The purpose of this blog is the creation of an open, international, independent and free forum, where every UFO-researcher can publish the results of his/her research. The languagues, used for this blog, are Dutch, English and French.You can find the articles of a collegue by selecting his category. Each author stays resposable for the continue of his articles. As blogmaster I have the right to refuse an addition or an article, when it attacks other collegues or UFO-groupes.
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Deze blog is opgedragen aan mijn overleden echtgenote Lucienne.
In 2012 verloor ze haar moedige strijd tegen kanker!
In 2011 startte ik deze blog, omdat ik niet mocht stoppen met mijn UFO-onderzoek.
BEDANKT!!!
Een interessant adres?
UFO'S of UAP'S, ASTRONOMIE, RUIMTEVAART, ARCHEOLOGIE, OUDHEIDKUNDE, SF-SNUFJES EN ANDERE ESOTERISCHE WETENSCHAPPEN - DE ALLERLAATSTE NIEUWTJES
UFO's of UAP'S in België en de rest van de wereld Ontdek de Fascinerende Wereld van UFO's en UAP's: Jouw Bron voor Onthullende Informatie!
Ben jij ook gefascineerd door het onbekende? Wil je meer weten over UFO's en UAP's, niet alleen in België, maar over de hele wereld? Dan ben je op de juiste plek!
België: Het Kloppend Hart van UFO-onderzoek
In België is BUFON (Belgisch UFO-Netwerk) dé autoriteit op het gebied van UFO-onderzoek. Voor betrouwbare en objectieve informatie over deze intrigerende fenomenen, bezoek je zeker onze Facebook-pagina en deze blog. Maar dat is nog niet alles! Ontdek ook het Belgisch UFO-meldpunt en Caelestia, twee organisaties die diepgaand onderzoek verrichten, al zijn ze soms kritisch of sceptisch.
Nederland: Een Schat aan Informatie
Voor onze Nederlandse buren is er de schitterende website www.ufowijzer.nl, beheerd door Paul Harmans. Deze site biedt een schat aan informatie en artikelen die je niet wilt missen!
Internationaal: MUFON - De Wereldwijde Autoriteit
Neem ook een kijkje bij MUFON (Mutual UFO Network Inc.), een gerenommeerde Amerikaanse UFO-vereniging met afdelingen in de VS en wereldwijd. MUFON is toegewijd aan de wetenschappelijke en analytische studie van het UFO-fenomeen, en hun maandelijkse tijdschrift, The MUFON UFO-Journal, is een must-read voor elke UFO-enthousiasteling. Bezoek hun website op www.mufon.com voor meer informatie.
Samenwerking en Toekomstvisie
Sinds 1 februari 2020 is Pieter niet alleen ex-president van BUFON, maar ook de voormalige nationale directeur van MUFON in Vlaanderen en Nederland. Dit creëert een sterke samenwerking met de Franse MUFON Reseau MUFON/EUROP, wat ons in staat stelt om nog meer waardevolle inzichten te delen.
Let op: Nepprofielen en Nieuwe Groeperingen
Pas op voor een nieuwe groepering die zich ook BUFON noemt, maar geen enkele connectie heeft met onze gevestigde organisatie. Hoewel zij de naam geregistreerd hebben, kunnen ze het rijke verleden en de expertise van onze groep niet evenaren. We wensen hen veel succes, maar we blijven de autoriteit in UFO-onderzoek!
Blijf Op De Hoogte!
Wil jij de laatste nieuwtjes over UFO's, ruimtevaart, archeologie, en meer? Volg ons dan en duik samen met ons in de fascinerende wereld van het onbekende! Sluit je aan bij de gemeenschap van nieuwsgierige geesten die net als jij verlangen naar antwoorden en avonturen in de sterren!
Heb je vragen of wil je meer weten? Aarzel dan niet om contact met ons op te nemen! Samen ontrafelen we het mysterie van de lucht en daarbuiten.
A artist's picture of Ganymede's magnetosphere. Illustration Credit: NASA, ESA, and G. Bacon (STScI); Science Credit: NASA, ESA, and J. Saur (University of Cologne, Germany)
We already know a decent amount about how planets form, but moon formation is another process entirely, and one we’re not as familiar with. Scientists think they understand how the most important Moon in our solar system (our own) formed, but its violent birth is not the norm, and can’t explain larger moon systems like the Galilean moons around Jupiter. A new book chapter (which was also released as a pre-print paper) from Yuhito Shibaike and Yann Alibert from the University of Bern discusses the differing ideas surrounding the formation of large moon systems, especially the Galileans, and how we might someday be able to differentiate them.
The Galilean moons form what is known as the circum-Jovian disc (CJD), and analogue of the circum-stellar disc (CSD) that surrounds the Sun, but instead has Jupiter at its center. The other 93+ non-Galilean moons around Jupiter also define the CJD, but their creation might be different due to the size differentials.
According to the paper, there are three main differences between the formation of planets and the formation of moons. Moon formation happens on a much faster time scale - around 10-100 times faster than planet formation. The system itself is also always gaining additional material from the CSD and losing it to whatever is at the center of the disk, which in the CJD’s case is Jupiter. And finally, there aren’t nearly as many examples of systems with multiple large moons as there are planetary systems, at least since the discovery of exoplanets 30 years ago. Jupiter and Saturn remain our only examples of large moon systems, and it will be awhile before any multi-exo-moon system will be found.
Fraser discusses the formation of our own Moon, which was dramatically different than that of the Galileans.
So what we can tell about the formation of these moon systems from the two we know about. The paper breaks the process down into a three-step process. First is the formation of the CJD, which includes gas and dust as well as moons. This was originally supported by a “minimum mass model” developed in the 1980s that assumed the disc was static and contained approximately the overall mass of the Galilean moons. In 2002, a new theory was developed that modeled the CJD as a “gas-starved disc” where the original CJD was relatively material poor but had plenty of additional material added to it by gravitational capture from the CSD.
That gravitational capture is believed to have played a key role in the formation of the Galilean moons and marks the second phase of their creation. However, Jupiter is a planet, and one of the requirements of a planet is that it clears its orbital path. Since Jupiter is the largest planet, it does so very effectively, which includes what astronomers consider “pebbles” (but on Earth could be considered a decent-sized boulder a few meters across).
One way for moons to accrete given this paucity of small material is by using even smaller material - small dust particles can make their way into the CJD without being disrupted by Jupiter, though there’s some debate about how effective this process is. Another method would be "planetesimal capture” where Jupiter’s gravity well catches the core of what would have ended up being a planet, but then ends up simply being one of the giant planet’s moons. They could have been gravitationally disturbed by Saturn, and then slowed in their orbit by running through the gas cloud surrounding early Jupiter that made up the CJD.
Fraser discusses the missions that will explore Jupiter's moons in more detail.
There are some differences in the Galilean moons themselves that can be used to prove or disprove these different formation theories. For example, Callisto isn’t in resonance with Jupiter at all, unlike the rest of its Galilean brethren. One potential theory for that is that Jupiter’s fourth moon was formed under different conditions, or maybe was hit by its own impactor that knocked it from its natural course. Callisto is again an outlier as it’s only partially “differentiated” (meaning it has a separate core, mantle, and outer shell), unlike its three compatriots. Some pebble accretion models think that Callisto is still early on in its formation journey and will eventually begin to look more like its peers.
But ultimately those questions, and many more about the formation of large moon systems, will be hard to answer without more data. The Jupiter Icy Moon Explorer (JUICE) mission will help shed some light on those questions, but even then it's still only one, or at the most two, data sets that we have available. Until exoplanet hunting telescopes become powerful enough to start finding exomoons as often as they currently find planets, many of these formation theories will remain untested. That data will eventually come along someday, and when it does it will help us understand some important parts of our own solar system better.
A scene from a visualization of the Lee-Lincoln scarp in Taurus-Littrow on the Moon. This scarp is evidence of moonquakes that sent rocks and landslides across the surface. Seismometers left on the Moon by Apollo astronauts recorded hundreds of events between 1969 and 1977, including 28 shallow moonquakes. The study narrowed the locations of these quakes and found that many of them occurred near scarps, implying that the forces creating the scarps also caused the quakes, and they continue to shape the lunar surface. The Lee-Lincoln scarp was only about 13 kilometers from one of the epicenters identified by the scientists. Credit: NASA's Scientific Visualization Studio
Our Moon is a seismically active world with a long history of quakes stretching back to its early history. It turns out those quakes can and will affect the safety of permanent base structures for anybody planning to explore and inhabit the Moon. That's one conclusion from a study of quakes along the Lee-Lincoln fault in the Taurus-Littrow valley where the Apollo 17 astronauts landed in 1972. “The global distribution of young thrust faults like the Lee-Lincoln fault, their potential to be still active and the potential to form new thrust faults from ongoing contraction should be considered when planning the location and assessing stability of permanent outposts on the Moon,” said Smithsonian senior scientist emeritus Thomas R. Watters, lead author of the paper.
They base their work on evidence of moonquakes in the region over the past 90 million years, largely in material gathered by the Apollo astronauts. Chunks of rocks and landslides are mute proof of the power of magnitude 3.0 quakes to shift the surface materials around. Along with other active faults on the Moon, the Taurus-Littrow rocks and landslides show that our lunar companion is likely still geologically active.
Why Lunar Seismicity?
Here on Earth, we get earthquakes all the time. By some estimates, our planet shakes about 55 times a day, although many of these tremors are so weak we don't feel them. They happen largely due to plate tectonics and volcanic activity. Plates slip past each other very gradually, which releases energy that gets dissipated as an earthquake. We all know about the really famous spots on Earth for that kind of action - the San Andreas Fault line, the Ring of Fire in the Pacific, and parts of southeast Asia, for example. Volcanic activity also spurs earthquakes when underground magma causes "shudders" as it moves. Recent events such as the ongoing Kilauea eruptions in Hawai'i and those near Grindavik, Iceland, cause swarms of earthquakes as a result of that magma movement.
However, that's not how it works on the Moon. The two most likely causes for lunar quakes are tidal pulling and the continual cooling and shrinking of the Moon. The tidal quakes happen because Earth's gravity pulls on the Moon, which results in deep quakes up to hundreds of miles inside. Weaker quakes originate closer to the surface and those are generally thought to be due to lunar shrinkage. Since the Moon formed billions of years ago, it has lost about 150 feet of its diameter due to the gradual cooling after its birth. There are also very minor temblors that happen when a meteoroid slams into the surface, or when surface rocks react to heating and cooling from the Sun. All this activity describes a world that is constantly shaking and shuddering.
This artist’s concept shows the Moon’s hot interior and volcanism about 2 to 3 billion years ago. It is thought that volcanic activity on the lunar near side (the side facing Earth) helped create a landscape dominated by vast plains called mare, which are formed by molten rock that cooled and solidified. As the Moon has continued to cool, it has shrunk and its surface contracted. That causes scarps and fault lines to form.
NASA/JPL-Caltech
Quakes and Risks
To understand the risk of quakes to future bases, Watters and research partner Nicholas Schmerr of the University of Maryland, studied materials from the Apollo 17 landing site. These rock samples, along with other details about rock falls and landslides on the Moon, told them that there are thousands of young thrust faults on the Moon. They point to a continual evolution of surface units, many caused by earthquake activities that create lunar thrust faults. That happens when rocks are compressed and one block is pushed up over another, generally as a result of the ongoing contraction of the Moon.
According to Watters and Schmerr, mission planners are going to have to consider those fault lines and the ongoing related lunar quakes when planning bases on the Moon. Short-term missions, like the Apollo landing, which had astronauts on the Moon for nearly 2 weeks, didn't face much danger from a quake or two. However, permanent bases face significant chances of damage during a quake, simply due to numbers. “If astronauts are there for a day, they’d just have very bad luck if there was a damaging event,” Schmerr pointed out. “But if you have a habitat or crewed mission up on the Moon for a whole decade, that’s 3,650 days times 1 in 20 million, or the risk of a hazardous moonquake becoming about 1 in 5,500. It’s similar to going from the extremely low odds of winning a lottery to much higher odds of being dealt a four of a kind poker hand.”
Taurus-Littrow valley taken by NASA’s Lunar Reconnaissance Orbiter spacecraft. The valley was explored in 1972 by the Apollo 17 mission astronauts Eugene Cernan and Harrison Schmitt. They had to zig-zag their lunar rover up and over the cliff face of the Lee-Lincoln fault scarp that cuts across this valley.
Credits: NASA/GSFC/Arizona State University
Planning for Quakes
It's not just habitats and science missions that could be damaged by lunar quakes. Russia, China, and the U.S. are planning to put nuclear power plants on the Moon. Such facilities could supply all the power anyone needs for bases and exploration, but they come with a safety price and could be quite susceptible to quake damage. That's why any these and other places need to be built with tough safety margins, and not located near any active fault lines. That's going to be a tall order, considering the extent of quakes and the numbers of fault lines that thread through the Moon.
This is why the scientists' study of lunar paleoseismology is so important. Gathering evidence of past quakes (going back many millennia), as well as more recent ones, is going to help chart the safest places to build bases, habitats, and power plants. “If astronauts are there for a day, they’d just have very bad luck if there was a damaging event,” Schmerr added. “But if you have a habitat or crewed mission up on the Moon for a whole decade, that’s 3,650 days times 1 in 20 million, or the risk of a hazardous moonquake becoming about 1 in 5,500. It’s similar to going from the extremely low odds of winning a lottery to much higher odds of being dealt a four of a kind poker hand.”
A scene from a visualization of the Lee-Lincoln scarp in Taurus-Littrow on the Moon. This scarp is evidence of moonquakes that sent rocks and landslides across the surface. Seismometers left on the Moon by Apollo astronauts recorded hundreds of events between 1969 and 1977, including 28 shallow moonquakes. The study narrowed the locations of these quakes and found that many of them occurred near scarps, implying that the forces creating the scarps also caused the quakes, and they continue to shape the lunar surface. The Lee-Lincoln scarp was only about 13 kilometers from one of the epicenters identified by the scientists. Credit: NASA's Scientific Visualization Studio
Our Moon is a seismically active world with a long history of quakes stretching back to its early history. It turns out those quakes can and will affect the safety of permanent base structures for anybody planning to explore and inhabit the Moon. That's one conclusion from a study of quakes along the Lee-Lincoln fault in the Taurus-Littrow valley where the Apollo 17 astronauts landed in 1972. “The global distribution of young thrust faults like the Lee-Lincoln fault, their potential to be still active and the potential to form new thrust faults from ongoing contraction should be considered when planning the location and assessing stability of permanent outposts on the Moon,” said Smithsonian senior scientist emeritus Thomas R. Watters, lead author of the paper.
They base their work on evidence of moonquakes in the region over the past 90 million years, largely in material gathered by the Apollo astronauts. Chunks of rocks and landslides are mute proof of the power of magnitude 3.0 quakes to shift the surface materials around. Along with other active faults on the Moon, the Taurus-Littrow rocks and landslides show that our lunar companion is likely still geologically active.
Why Lunar Seismicity?
Here on Earth, we get earthquakes all the time. By some estimates, our planet shakes about 55 times a day, although many of these tremors are so weak we don't feel them. They happen largely due to plate tectonics and volcanic activity. Plates slip past each other very gradually, which releases energy that gets dissipated as an earthquake. We all know about the really famous spots on Earth for that kind of action - the San Andreas Fault line, the Ring of Fire in the Pacific, and parts of southeast Asia, for example. Volcanic activity also spurs earthquakes when underground magma causes "shudders" as it moves. Recent events such as the ongoing Kilauea eruptions in Hawai'i and those near Grindavik, Iceland, cause swarms of earthquakes as a result of that magma movement.
However, that's not how it works on the Moon. The two most likely causes for lunar quakes are tidal pulling and the continual cooling and shrinking of the Moon. The tidal quakes happen because Earth's gravity pulls on the Moon, which results in deep quakes up to hundreds of miles inside. Weaker quakes originate closer to the surface and those are generally thought to be due to lunar shrinkage. Since the Moon formed billions of years ago, it has lost about 150 feet of its diameter due to the gradual cooling after its birth. There are also very minor temblors that happen when a meteoroid slams into the surface, or when surface rocks react to heating and cooling from the Sun. All this activity describes a world that is constantly shaking and shuddering.
This artist’s concept shows the Moon’s hot interior and volcanism about 2 to 3 billion years ago. It is thought that volcanic activity on the lunar near side (the side facing Earth) helped create a landscape dominated by vast plains called mare, which are formed by molten rock that cooled and solidified. As the Moon has continued to cool, it has shrunk and its surface contracted. That causes scarps and fault lines to form.
NASA/JPL-Caltech
Quakes and Risks
To understand the risk of quakes to future bases, Watters and research partner Nicholas Schmerr of the University of Maryland, studied materials from the Apollo 17 landing site. These rock samples, along with other details about rock falls and landslides on the Moon, told them that there are thousands of young thrust faults on the Moon. They point to a continual evolution of surface units, many caused by earthquake activities that create lunar thrust faults. That happens when rocks are compressed and one block is pushed up over another, generally as a result of the ongoing contraction of the Moon.
According to Watters and Schmerr, mission planners are going to have to consider those fault lines and the ongoing related lunar quakes when planning bases on the Moon. Short-term missions, like the Apollo landing, which had astronauts on the Moon for nearly 2 weeks, didn't face much danger from a quake or two. However, permanent bases face significant chances of damage during a quake, simply due to numbers. “If astronauts are there for a day, they’d just have very bad luck if there was a damaging event,” Schmerr pointed out. “But if you have a habitat or crewed mission up on the Moon for a whole decade, that’s 3,650 days times 1 in 20 million, or the risk of a hazardous moonquake becoming about 1 in 5,500. It’s similar to going from the extremely low odds of winning a lottery to much higher odds of being dealt a four of a kind poker hand.”
Taurus-Littrow valley taken by NASA’s Lunar Reconnaissance Orbiter spacecraft. The valley was explored in 1972 by the Apollo 17 mission astronauts Eugene Cernan and Harrison Schmitt. They had to zig-zag their lunar rover up and over the cliff face of the Lee-Lincoln fault scarp that cuts across this valley.
Credits: NASA/GSFC/Arizona State University
Planning for Quakes
It's not just habitats and science missions that could be damaged by lunar quakes. Russia, China, and the U.S. are planning to put nuclear power plants on the Moon. Such facilities could supply all the power anyone needs for bases and exploration, but they come with a safety price and could be quite susceptible to quake damage. That's why any these and other places need to be built with tough safety margins, and not located near any active fault lines. That's going to be a tall order, considering the extent of quakes and the numbers of fault lines that thread through the Moon.
This is why the scientists' study of lunar paleoseismology is so important. Gathering evidence of past quakes (going back many millennia), as well as more recent ones, is going to help chart the safest places to build bases, habitats, and power plants. “If astronauts are there for a day, they’d just have very bad luck if there was a damaging event,” Schmerr added. “But if you have a habitat or crewed mission up on the Moon for a whole decade, that’s 3,650 days times 1 in 20 million, or the risk of a hazardous moonquake becoming about 1 in 5,500. It’s similar to going from the extremely low odds of winning a lottery to much higher odds of being dealt a four of a kind poker hand.”
This artist’s concept depicts planet TRAPPIST-1 d passing in front of its turbulent star, with other members of the closely packed system shown in the background. Image Credit: NASA, ESA, CSA, J. Olmsted (STScI)
When global events set our minds to wondering if humanity has what it takes to persist, it's natural to wonder about other worlds, other life, other intelligent species, and if those others might be better suited to survive whatever Great Filters they face. Those are fanciful thoughts, but there's an underpinning of nuts-and-bolts thinking to them. It starts with identifying which planets in habitable zones around other stars might actually be habitable.
That begins with liquid water and a life-friendly atmosphere that can contain it.
The discovery of the TRAPPIST-1 system generated a lot of excitement a few years ago. It contains seven roughly Earth-like worlds, and three or perhaps four of them are in the red dwarf's compact habitable zone. One of them, TRAPPIST-1 d, could host water on its surface, or at least on parts of its surface, according to some research. But without a suitable atmosphere, a planet can't retain surface water, and new observations from the JWST show that TRAPPIST-1 d does not have an Earth-like atmosphere.
The TRAPPIST-1 system compared to our Solar System. TRAPPIST-1 d is on the inner edge of the star's habitable zone.
Image Credit: NASA/JPL-Caltech
The JWST observed two consecutive transits of TRAPPIST-1 d with its NIRSpec/PRISM instrument in November, 2022. Researchers from Canada, the UK, France, and the USA analyzed the data from those transits and concluded that the promising exoplanet does not have an Earth-like atmosphere. Their results are in a paper in The Astrophysical Journal titled "Strict Limits on Potential Secondary Atmospheres on the Temperate Rocky Exo-Earth TRAPPIST-1 d." The lead author is Caroline Piaulet-Ghorayeb of the University of Chicago and Trottier Institute for Research on Exoplanets (IREx) at Université de Montréal.
"While TRAPPIST-1 d may prove a barren rock illuminated by a cruel red star, the outer planets TRAPPIST-1e, f, g, and h, may yet possess thick atmospheres." - co-author Ryan MacDonald, University of St. Andrews.
"The nearby TRAPPIST-1 system, with its seven small rocky planets orbiting a late-type M8 star, offers an unprecedented opportunity to search for secondary atmospheres on temperate terrestrial worlds," the authors write in their research. "Here we present the first 0.6–5.2 μm NIRSpec/PRISM transmission spectrum of TRAPPIST-1 d from two transits with JWST."
TRAPPIST-1 d is right at the inner edge of TRAPPIST-1's habitable zone. It's a great target for transmission spectroscopy, and these JWST observations provide the first detailed transmission spectrum of the planet's atmosphere. Unfortunately, the spectrum is flat, meaning there are no detectable atmospheric features.
“Ultimately, we want to know if something like the environment we enjoy on Earth can exist elsewhere, and under what conditions. While the James Webb Space Telescope is giving us the ability to explore this question in Earth-sized planets for the first time, at this point we can rule out TRAPPIST-1 d from a list of potential Earth twins or cousins,” said lead author Piaulet-Ghorayeb in a press release.
The JWST failed to detect the types of molecules present in Earth's atmosphere like methane, carbon dioxide, and water. However, that doesn't completely rule out an atmosphere; there are a couple of other possibilities.
“There are a few potential reasons why we don’t detect an atmosphere around TRAPPIST-1 d. It could have an extremely thin atmosphere that is difficult to detect, somewhat like Mars. Alternatively, it could have very thick, high-altitude clouds that are blocking our detection of specific atmospheric signatures — something more like Venus. Or, it could be a barren rock, with no atmosphere at all,” Piaulet-Ghorayeb said.
Studying TRAPPIST-1 d and its atmosphere is about more than just ruling out its habitability. There's a greater scientific endeavor involved.
A visual comparison of Solar System orbits, TRAPPIST-1 orbits, and Galilean moon orbits.
Image Credit: By ESO/O. Furtak - http://www.eso.org/public/images/eso1706b/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=56526718
Red dwarfs, or M dwarfs, like TRAPPIST-1 are common, and are likely the most plentiful type of star in the Milky Way. They're known to host their share of rocky worlds where we can reasonably wonder if life persists. But red dwarfs are also known for their violent flaring, and TRAPPIST-1 is no exception. It flares every couple of days, and each year it emits between four and six superflares. This powerful flaring activity could shred any planetary atmospheres, rendering the TRAPPIST-1 planets inhabitable.
However, there's considerable uncertainty around red dwarf flaring and habitability. Some research shows that the planets couldn't retain atmospheres in the face of the coronal mass ejections coming from the star. But it's at least possible that some of these planets could retain their atmospheres. For example, powerful planetary magnetic fields could provide a protective barrier from the star's flaring. The JWST opens a path to understanding red dwarf flaring effects on atmospheres.
“Webb’s sensitive infrared instruments are allowing us to delve into the atmospheres of these smaller, colder planets for the first time,” said Björn Benneke of IREx at Université de Montréal, a co-author of the study. “We’re really just getting started using Webb to look for atmospheres on Earth-sized planets, and to define the line between planets that can hold onto an atmosphere, and those that cannot.”
The only features in the JWST's spectra are attributed to stellar contamination rather than atmospheric absorption. "Our precise transmission spectrum can be fully explained by stellar contamination alone, and therefore enables us to rule out cloud-free or thick atmosphere scenarios across a wide range of potential atmospheric metallicities," the authors write.
This artist's illustration of TRAPPIST-1 d is from several years ago when scientists wondered about its nature and if it could support liquid water.
Updated Feb. 2018, Public Domain, https://commons.wikimedia.org/w/index.php?curid=76364484
A low molecular weight atmosphere is harder for a planet to retain, and these observations ruled out those types of hydrogen-dominated atmospheres. The observations also ruled out thicker atmospheres like Venus' or Titan's. The only things left are extremely thin atmospheres unlikely to bolster habitability, or atmospheres dominated by high clouds that mask molecular absorption features from the JWST. But the research effectively rules them out.
"Therefore, we conclude that
thick cloud-free hydrogen-rich atmospheres are ruled out by our transmission spectrum;
thin H2-rich alternatives are strongly disfavored when considering TRAPPIST-1 d in the context of its formation and evolution under stellar irradiation; and
high-altitude clouds or hazes are not expected to form on TRAPPIST-1 d if it has a low-metallicity atmosphere," the researchers explain.
This work almost certainly eliminates TRAPPIST-1 d from a list of potentially habitable, water-supporting exoplanets. This is Nature, so TRAPPIST-1 d's elimination isn't absolutely certain. "Our observations cannot yet completely exclude other potential atmosphere scenarios for TRAPPIST-1 d which were predicted in the literature," the authors explain, noting that other research involving climate models hints at the possibility that the tidally-locked planet could form high-altitude water clouds at its terminator, blocking atmospheric absorption signals from view.
But what about the other planets in the system?
“All hope is not lost for atmospheres around the TRAPPIST-1 planets,” Piaulet-Ghorayeb said. “While we didn’t find a big, bold atmospheric signature at planet d, there is still potential for the outer planets to be holding onto a lot of water and other atmospheric components.”
However, the outer planets aren't the juicy scientific targets that planet d is. They're further from the star, and colder. Even the JWST's powerful instruments struggle in those conditions. While detailed spectra aren't available for those worlds, the researchers still reached some conclusion.
"We find that even complete atmosphere loss for TRAPPIST-1 d would not preclude atmosphere presence for the outer HZ planets TRAPPIST-1 e, f, and g," the authors write in their conclusion. Contrary to the inner planets, it's possible that these outer planets held onto their water "even if they initially accreted only a few Earth oceans of volatiles."
“Our detective work is just beginning. While TRAPPIST-1 d may prove a barren rock illuminated by a cruel red star, the outer planets TRAPPIST-1e, f, g, and h, may yet possess thick atmospheres," added Ryan MacDonald, a co-author of the paper, now at the University of St Andrews in the United Kingdom, and previously at the University of Michigan. “Thanks to Webb we now know that TRAPPIST-1 d is a far cry from a hospitable world. We're learning that the Earth is even more special in the cosmos."
Being a human being means bearing witness to humanity's greatest, most triumphant moments of accomplishment and unity, but also to the depraved actions we take against one another. The minds of thinking people are bound to wonder if there are other worlds out there that host life. Each potentially habitable world is a glimmer of hope that humans, with all their struggles, are not the only intelligent species out there.
If we look to the heavens, and to exoplanets, for some kind of reprieve from humanity's troubles, TRAPPIST-1 d won't provide it. If this research is correct, its stricken from the list of hope-inspiring exoplanets.
What invaded our solar system? On July 1st, NASA's ATLAS telescope in Chile identified an unusual object soaring through our solar system. It was later determined that this strange celestial object originated from beyond our little corner of the universe.
Traveling at a remarkably high speed Originating from the constellation Sagittarius, scientists observed that the object traveled at a speed of more than 60 kilometers per second, or about 37 miles per second. That is incredibly fast!
A rare phenomenon According to researchers, this was the third interstellar visitor of this type ever identified by humanity, as highlighted by National Geographic.
Researchers gave the object a name Named 3I/ATLAS, the interstellar object was classified by researchers as a comet. However, a NASA webpage on the new interstellar object reported that the comet's size and physical properties are still being investigated.
What we know about the size of 3I/ATLAS Comet 3I/ATLAS's size was estimated at 10 to 20 kilometers (6 to 12 miles) in diameter, but could be smaller if it is composed of ice, which means the comet would also reflect more light.
Could 3I/ATLAS impact Earth? 3I/ATLAS reportedly does not pose a risk to the Earth and will pass by far from our planet at a distance of about 1.6 astronomical units (equivalent to about 240 million kilometers or 250 million miles), NASA reported.
The comet will pass close to Mars The newly discovered interstellar comet's closest approach to the Sun is expected to occur around October 30th, when it will be slightly closer to the orbit of Mars, according to current research on 3I/ATLAS.
A seven billion year old space rock According to astronomers, 3I/ATLAS might have formed long before our solar system existed. The comet reportedly has an estimated age of seven billion years, Deutsche Welle reported.
Photo Credit: NASA, ESA, David Jewitt (UCLA); Image Processing: Joseph DePasquale (STScI)
The oldest comet ever observed Matthew Hopkins, lead author of a study on 3I/ATLAS, and an astronomer at the University of Oxford, explained in a statement published by the Royal Astronomical Society that the newly discovered interstellar object is very likely the oldest comet ever observed by humanity.
3I/ATLAS will be visible until September 3I/ATLAS should remain visible in the night sky through ground-based telescopes until September 2025. After that, it will be too close to the Sun to be observable from Earth.
Proximity to the Sun Deutsche Welle also reported that as the comet approaches the Sun, the heat from sunlight will warm its surface and trigger cometary activity, releasing gas and dust, with a bright 'aura' around it and a visible tail.
We might be able to see the comet again 3I/ATLAS is expected to reappear on the other side of the Sun sometime in early December 2025, which will allow researchers to gather even more observations about the comet, NASA reported.
A unique opportunity to expand our knowledge "This is an object from a part of the galaxy we've never seen up close before," Professor Chris Lintott, co-author of the study, was quoted as saying by the Royal Astronomical Society.
The evolution of the comet Researchers are excited since interstellar comets like 3I/ATLAS can carry valuable clues about the origin of the universe and the star systems where these types of cosmic objects originate before making their way to us.
The world is watching "We're in an exciting time: 3I is already showing signs of activity," noted study co-author Dr. Michele Bannister, of the University of Canterbury in New Zealand, according to the Royal Astronomical Society.
The world's biggest telescopes are already investigating "The gases that may be seen in the future as 3I is heated by the Sun will test our model," Dr. Bannister added. "Some of the biggest telescopes in the world are already observing this new interstellar object."
Understanding the formation of the universe As highlighted by National Geographic, the researchers' goal is to identify the comet's composition in order to study how planets form, how other star systems evolve, and the diversity of materials present in the universe.
Scientists have examined scientific articles and media publications from the last 30 years devoted to the search for extraterrestrial life. They analyzed in which aspects and promises scientists were overly optimistic, and in which journalists distorted everything.
Is there life on other planets?
Research into extraterrestrial life
So far, no life has been found beyond Earth, but publications about the prospects for such research continue to appear one after another. And not only in scientific publications, but also in popular media. At the same time, it is difficult to give a simple answer as to whether modern science is really sure of its existence.
Researchers from Leiden University attempted to figure this out. In a study recently published in PLOS One, they took a bunch of studies, press releases, and newspaper articles on the subject from 1996 to 2024 and analyzed what they were overly optimistic about and what they were not.
The total number of articles analyzed was 630. Most of them were in English, although there were also publications in Spanish and Portuguese. In particular, sources included The New York Times (United States), The Guardian (United Kingdom), Folha and Estadão (Brazil), Público (Portugal), and El País (Spain).
Is there any exaggeration?
Researchers found that most often the distortion concerned the conditions necessary for life to exist outside Earth, i.e., the question of the “key condition.” However, speculation about the results of research and the prospects for detecting life was relatively rare.
The study showed that expectations regarding technology helping to find life beyond Earth are relatively high. They appear in about a third of news articles, a fifth of press releases, and a tenth of scientific articles. The promise of rapid development in astrobiology in the near future was also quite widespread. Approximately one-fifth of press releases and news articles contained such content.
However, there are very few promises to find extraterrestrial life in publications, at least in those that appeared in peer-reviewed journals. There is much more manipulation in newspaper publications. Press releases remained largely neutral except for the part about the research results, which were usually exaggerated.
The study also reveals that expectations for the search for life are more closely linked to the study of exoplanets than to the study of the Solar System, and are much higher than for the search for extraterrestrial intelligence (SETI).
There is indeed a lot of speculation. However, according to the authors of the study, this is not such a bad thing. After all, there is so much unknown in the Universe, and in order to develop new bold theories, we need to move beyond what we see here and now.
The exact location of the most distant known galaxy, JADES-GS-z14-0. Source: Space Telescope Science Institute Office of Public Outreach via CNN Newsource
Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have detected traces of oxygen in the extremely distant and ancient galaxy JADES-GS-z14-0, whose light has been traveling toward us for 13.4 billion years. This means that we see it as it was when the Universe was less than 300 million years old. Previously, it was believed that heavy elements such as oxygen could not have appeared at that time.
The discovery indicates that at least two generations of stars have already been born and died in this galaxy, scattering “metals” (as astronomers call all elements heavier than helium) throughout space. This is very fast by cosmic standards and contradicts older models, which assumed that such enrichment would take hundreds of millions of years.
ALMA was able to determine the distance to this galaxy very accurately, with an error of only 0.005%. It turned out that the gas in it contained about 20% of the “metals” found in the Sun, and the movements of the ionized gas hinted at a large halo of dark matter.
“I was amazed by the unexpected results, because they opened up a new perspective on the early phases of galaxy evolution,” said Stefano Carniani from the Scuola Normale Superiore University in Pisa.
This discovery is forcing scientists to rethink their theories about the formation of the first galaxies. Perhaps the star systems of that time formed and exploded much faster and more energetically than researchers had assumed.
Scientists plan to study this galaxy using the James Webb Telescope and the future Very Large Telescope to understand whether it was a cosmic “wunderkind” or whether there were many such early and mature galaxies in the Universe.
It went through the roof, HAVC duct, and left a hole in the floor the size of a cherry tomato.
Planetary geologist Scott Harris concluded the space rock formed 4.56 billion years ago, roughly 20 million years before Earth.
'It belongs to a group of asteroids in the main asteroid belt between Mars and Jupiter that we now think we can tie to a breakup of a much larger asteroid about 470 million years ago,' Harris said.
The homeowner said he continues to find specks of space dust scattered around his living room from the impact.
The meteorite shot through a man's home in Georgia. He gave the fragments to scientists who revealed their findings this week
The 23 gram fragment showed the meteorite is about 20 million years older than Earth
'A mysterious extraterrestrial visitor now has a permanent home and identity, thanks to University of Georgia (UGA) researchers,' the team shared in a press release.
'Multiple fragments, which tore through a residential roof in Henry County, were turned over to a UGA planetary geologist and impact expert to determine.'
Before breaking into fragments small enough to analyze, the meteor, known as a bolide, was recorded entering Earth's atmosphere at an incredible cosmic velocity.
This massive space rock hurtled toward McDonough at speeds exceeding the speed of sound.
'When they encounter Earth, our atmosphere is very good at slowing them down,' Harris said.
'But you're talking about something that is double the size of a 50-caliber shell, going at least 2,236 miles per second. That's like running 10 football fields in one second.'
Using optical and electron microscopy to examine the fragments, Harris identified the meteorite as a Low Metal (L) ordinary Chondrite.
This classification indicates the meteorite likely formed 4.56 billion years ago in an oxygen-rich environment.
The meteorite still had enough impact to go through a man's roof and his HVAC duct, leave a solid dent in his floor and make a sound and vibration equivalent to a close-range gunshot
The tiny space rock was traveling at amazing speeds, enough to smash through a roof, HVAC duct and ceiling
This is the 27th meteorite recovered in Georgia in history, and the sixth witnessed fall.
Harris said the fragment broke the sound barrier when it entered the Earth's atmosphere.
Several metro Atlanta city and county officials relayed reports of a 'fireball' sighting from the sky on June 26
'I'm not crazy! I just saw a huge ball of fire fall from the sky in East Tennessee around the Cherokee National Forest!' a firefighter wrote on X.
'Anyone else see it? Right around 12:20pm ET. Very cool but a little unnerving given the current times!'
While some speculated it could have been a falling aircraft, the firefighter described it as 'like a mini sun falling with a tail of fire.'
In Georgia, one resident said they not only saw the object, but heard it pass overhead and felt the ground shake when it hit.
The National Weather Service confirmed the many reports across the Southeast US saying: 'It is not certain, but the satellite-based lightning detection shows a streak within cloud-free sky over the NC/VA border, over Gasbury, VA.
'This streak was detected between 12:51 to 12:56 pm.'
Hundreds of reports of a possible fireball were submitted to the American Meteor Society website from Georgia, South Carolina and Tennessee, which are still pending.
A flaming object was seen streaking across the skies of several southern states, sparking panic and confusion, as no explosion or fire were reported on the ground
'This was the middle of the day, and it just came out of nowhere,' according to one fireball report on the American Meteor Society from Perry, Georgia.
A report submitted by Ashley R from Suwanee, Georgia read: 'I thought it was a missile.'
Brian S from Alpharetta, Georgia said: 'It was full daylight, no clouds, and still it was very bright. I heard a muffled and slight boom sound, maybe 30 seconds later, but that could be unrelated.'
He added that he saw a 'smoke trail that quickly fell apart.'
Marc Tozer of Georgia shared on Facebook: 'Stone mountain here and it made a booming sound, house shook with a long rumble. Dogs went crazy.'
Another Georgia local posted: 'House totally rumbled, sounded like a log rolling off the roof, thought nukes were coming...'
WRDW, an Atlanta news source, reported that black smoke was seen south of I-20, although it may be from a controlled burn, first responders said.
Scientists are urging NASA to send a message to a mysterious interstellar object before it is too late.
The object, known as 3I/ATLAS, is traveling on a rare retrograde path and will reach its closest point to the sun on October 29, 2025, which Harvard physicist Avi Loeb suggested could be an ideal window for a covert approach on Earth.
The physicist told the Daily Mail that he wants to beam, 'Hello, welcome to our neighborhood. Peace!'
'The only way to reach it now is with a beam of light,' Loeb explained, suggesting a radio message could be sent in hopes of detecting a response.
Loeb warned that if the object is an alien probe, it could reach Earth by Christmas 2025, giving humanity only months to prepare for a possible encounter.
However, he also acknowledged the risks, noting that any intelligent life aboard might see the signal as a threat.
'A visitor to our backyard, like 3I/ATLAS, can easily enter our home planet, Earth, within a travel time of less than a few months,' Loeb said.
A Harvard physicist is calling on NASA to beam a message to the interstellar object hurting through space before it is too late
'There were claims of a tail,' Loeb said, 'but since 3I/ATLAS is accelerating and its current size is not much larger than the angular resolution of Earth-based telescopes, it is not easy to avoid fictitious elongation of the image as a result of the object's motion.'
He also questioned the object's unusual lack of gas emissions and its precise, retrograde trajectory, which aligns suspiciously well with the inner solar system.
Loeb has developed what he calls the 'Loeb Scale', a ranking system to evaluate the likelihood that an object is artificial, and gave 3I/ATLAS a six out of ten.
That suggests it is more likely than not to be engineered, though he emphasized that this score may change as more data becomes available.
'During an exchange with 3I/ATLAS, we could use the Turing Test as a measure of the intelligence with which we communicate, as long as the two sides develop a common language for communication,' Loeb shared in a blog post.
'Our side of the communication channel can be assisted by our most advanced artificial intelligence systems to decode the messages we receive.
The scientist noted that there is not enough data to rule out that the object is not of alien origin and Earth should communicate with it as a precaution
Avi Loeb has remained adamant that something about 3I/ATLAS does not add up. He said its retrograde orbit, meaning it's moving against the flow of the solar system, is oddly aligned with Earth's path
'But as anyone who went on a blind date knows, exchanging text messages could be a very different experience than an actual encounter 'in person.''
Among his more provocative theories, Loeb suggested 3I/ATLAS could be an alien mothership releasing small probes to intercept Earth.
'The more likely scenario from an engineering perspective involves a mothership that releases mini-probes which perform a reverse Oberth maneuver to slow down at perihelion and intercept Earth,' Loeb wrote.
This type of maneuver uses the sun's gravitational pull at the object's closest approach to adjust the trajectory efficiently, enabling the probes to reach Earth without large amounts of fuel.
Chris Lintott, an astronomer at the University of Oxford, dismissed Loeb's theory as 'nonsense on stilts,' calling it 'an insult to the exciting work going on to understand this object.'
However, Loeb said his analysis remains rooted in observational data.
His latest paper, based on ground-based telescope readings between July 2 and 29, revealed reddening colors in 3I/ATLAS, usually interpreted as surface dust or organic compounds.
Loeb noted that spectroscopic data from this and three previous studies show no signs of atomic or molecular gas in a coma, a feature typically expected in comets.
While the reddening may suggest dust, it could also mean the object simply has a naturally red surface, much like D-type asteroids or other ancient space rocks.
'Continued monitoring around perihelion is necessary to track changes in activity and color,' the study concluded, 'which will provide insights into the evolution of interstellar materials under solar radiation.'
The Eye of Sauron is an integral part of the Lord of the Rings series.
The flaming, floating fiery eyeball, positioned atop a dark tower in Mordor, is a symbol of the Dark Lord's all–seeing power and vigilance.
Now, experts have detected a similarly terrifying vision in real life.
But rather than looking for Frodo or the Ring, it seems to be peering directly at us from deep space.
The image is of a phenomenon called a cosmic jet, which is an extremely powerful stream of plasma and energy emitted from celestial objects.
This particular one comes from a blazar – a type of galaxy powered by a supermassive black hole.
The PKS 1424+240 blazar is one of the brightest in the sky despite being located billions of light–years away.
And as well as a foreboding picture, the discovery may have helped researchers solve a decades–long cosmic puzzle.
Using 15 years of ultra–precise radio observations, researchers were able to stitch together a deep image of the jet at unparalleled resolution
Fans of fantasy might notice that the image bears a striking resemblance to the Eye of Sauron from The Lord of the Rings
The blazar has long baffled astronomers as its cosmic jet appeared to move slowly, despite it being one of the brightest sources of high–energy gammas rays and cosmic neutrinos ever observed.
This contradicted the belief that only the fastest jets could be behind such exceptional brightness.
Using 15 years of ultra–precise radio observations from the Very Long Baseline Array – a system of 10 radio telescopes – researchers were able to stitch together a deep image of the jet at unparalleled resolution.
'When we reconstructed the image, it looked absolutely stunning,' lead author Yuri Kovalev, from the Max Planck Institute for Radio Astronomy, said.
'We have never seen anything quite like it—a near–perfect toroidal magnetic field with a jet, pointing straight at us.'
Since the jet is aligned almost exactly in the direction of Earth, its high–energy radio emissions are dramatically amplified.
'This alignment causes a boost in brightness by a factor of 30 or more,' co–author Jack Livingston said.
'At the same time, the jet appears to move slowly due to projection effects—a classic optical illusion.'
Far from being a flattering moniker, the Eye of Sauron represents the Dark Lord's terrifying omnipotence and terrible gaze in J. R. R. Tolkein's Lord of the Rings novels
This head–on view also gave scientists the extremely rare opportunity to peer directly into the heart of the blazar's jet.
Radio signals helped the team map out the structure of the jet's magnetic field, revealing it is likely helical (a spiral) or toroidal (doughnut–shaped).
This structure likely plays a key role in accelerating particles to extreme energies, the researchers said.
Black holes are so dense and their gravitational pull is so strong that no form of radiation can escape them - not even light.
They act as intense sources of gravity which hoover up dust and gas around them. Their intense gravitational pull is thought to be what stars in galaxies orbit around.
How they are formed is still poorly understood. Astronomers believe they may form when a large cloud of gas up to 100,000 times bigger than the sun, collapses into a black hole.
Many of these black hole seeds then merge to form much larger supermassive black holes, which are found at the centre of every known massive galaxy.
Alternatively, a supermassive black hole seed could come from a giant star, about 100 times the sun's mass, that ultimately forms into a black hole after it runs out of fuel and collapses.
When these giant stars die, they also go 'supernova', a huge explosion that expels the matter from the outer layers of the star into deep space.
This artist’s concept depicts planet TRAPPIST-1 d passing in front of its turbulent star, with other members of the closely packed system shown in the background. Image Credit: NASA, ESA, CSA, J. Olmsted (STScI)
When global events set our minds to wondering if humanity has what it takes to persist, it's natural to wonder about other worlds, other life, other intelligent species, and if those others might be better suited to survive whatever Great Filters they face. Those are fanciful thoughts, but there's an underpinning of nuts-and-bolts thinking to them. It starts with identifying which planets in habitable zones around other stars might actually be habitable.
That begins with liquid water and a life-friendly atmosphere that can contain it.
The discovery of the TRAPPIST-1 system generated a lot of excitement a few years ago. It contains seven roughly Earth-like worlds, and three or perhaps four of them are in the red dwarf's compact habitable zone. One of them, TRAPPIST-1 d, could host water on its surface, or at least on parts of its surface, according to some research. But without a suitable atmosphere, a planet can't retain surface water, and new observations from the JWST show that TRAPPIST-1 d does not have an Earth-like atmosphere.
The TRAPPIST-1 system compared to our Solar System. TRAPPIST-1 d is on the inner edge of the star's habitable zone.
Image Credit: NASA/JPL-Caltech
The JWST observed two consecutive transits of TRAPPIST-1 d with its NIRSpec/PRISM instrument in November, 2022. Researchers from Canada, the UK, France, and the USA analyzed the data from those transits and concluded that the promising exoplanet does not have an Earth-like atmosphere. Their results are in a paper in The Astrophysical Journal titled "Strict Limits on Potential Secondary Atmospheres on the Temperate Rocky Exo-Earth TRAPPIST-1 d." The lead author is Caroline Piaulet-Ghorayeb of the University of Chicago and Trottier Institute for Research on Exoplanets (IREx) at Université de Montréal.
"While TRAPPIST-1 d may prove a barren rock illuminated by a cruel red star, the outer planets TRAPPIST-1e, f, g, and h, may yet possess thick atmospheres."
- co-author Ryan MacDonald, University of St. Andrews.
"The nearby TRAPPIST-1 system, with its seven small rocky planets orbiting a late-type M8 star, offers an unprecedented opportunity to search for secondary atmospheres on temperate terrestrial worlds," the authors write in their research. "Here we present the first 0.6–5.2 μm NIRSpec/PRISM transmission spectrum of TRAPPIST-1 d from two transits with JWST."
TRAPPIST-1 d is right at the inner edge of TRAPPIST-1's habitable zone. It's a great target for transmission spectroscopy, and these JWST observations provide the first detailed transmission spectrum of the planet's atmosphere. Unfortunately, the spectrum is flat, meaning there are no detectable atmospheric features.
“Ultimately, we want to know if something like the environment we enjoy on Earth can exist elsewhere, and under what conditions. While the James Webb Space Telescope is giving us the ability to explore this question in Earth-sized planets for the first time, at this point we can rule out TRAPPIST-1 d from a list of potential Earth twins or cousins,” said lead author Piaulet-Ghorayeb in a press release.
The JWST failed to detect the types of molecules present in Earth's atmosphere like methane, carbon dioxide, and water. However, that doesn't completely rule out an atmosphere; there are a couple of other possibilities.
“There are a few potential reasons why we don’t detect an atmosphere around TRAPPIST-1 d. It could have an extremely thin atmosphere that is difficult to detect, somewhat like Mars. Alternatively, it could have very thick, high-altitude clouds that are blocking our detection of specific atmospheric signatures — something more like Venus. Or, it could be a barren rock, with no atmosphere at all,” Piaulet-Ghorayeb said.
Studying TRAPPIST-1 d and its atmosphere is about more than just ruling out its habitability. There's a greater scientific endeavor involved.
A visual comparison of Solar System orbits, TRAPPIST-1 orbits, and Galilean moon orbits.
Image Credit: By ESO/O. Furtak - http://www.eso.org/public/images/eso1706b/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=56526718
Red dwarfs, or M dwarfs, like TRAPPIST-1 are common, and are likely the most plentiful type of star in the Milky Way. They're known to host their share of rocky worlds where we can reasonably wonder if life persists. But red dwarfs are also known for their violent flaring, and TRAPPIST-1 is no exception. It flares every couple of days, and each year it emits between four and six superflares. This powerful flaring activity could shred any planetary atmospheres, rendering the TRAPPIST-1 planets inhabitable.
However, there's considerable uncertainty around red dwarf flaring and habitability. Some research shows that the planets couldn't retain atmospheres in the face of the coronal mass ejections coming from the star. But it's at least possible that some of these planets could retain their atmospheres. For example, powerful planetary magnetic fields could provide a protective barrier from the star's flaring. The JWST opens a path to understanding red dwarf flaring effects on atmospheres.
“Webb’s sensitive infrared instruments are allowing us to delve into the atmospheres of these smaller, colder planets for the first time,” said Björn Benneke of IREx at Université de Montréal, a co-author of the study. “We’re really just getting started using Webb to look for atmospheres on Earth-sized planets, and to define the line between planets that can hold onto an atmosphere, and those that cannot.”
The only features in the JWST's spectra are attributed to stellar contamination rather than atmospheric absorption. "Our precise transmission spectrum can be fully explained by stellar contamination alone, and therefore enables us to rule out cloud-free or thick atmosphere scenarios across a wide range of potential atmospheric metallicities," the authors write.
This artist's illustration of TRAPPIST-1 d is from several years ago when scientists wondered about its nature and if it could support liquid water.
Updated Feb. 2018, Public Domain, https://commons.wikimedia.org/w/index.php?curid=76364484
A low molecular weight atmosphere is harder for a planet to retain, and these observations ruled out those types of hydrogen-dominated atmospheres. The observations also ruled out thicker atmospheres like Venus' or Titan's. The only things left are extremely thin atmospheres unlikely to bolster habitability, or atmospheres dominated by high clouds that mask molecular absorption features from the JWST. But the research effectively rules them out.
"Therefore, we conclude that (1) thick cloud-free hydrogen-rich atmospheres are ruled out by our transmission spectrum; (2) thin H2-rich alternatives are strongly disfavored when considering TRAPPIST-1 d in the context of its formation and evolution under stellar irradiation; and (3) high-altitude clouds or hazes are not expected to form on TRAPPIST-1 d if it has a low-metallicity atmosphere," the researchers explain.
This work almost certainly eliminates TRAPPIST-1 d from a list of potentially habitable, water-supporting exoplanets. This is Nature, so TRAPPIST-1 d's elimination isn't absolutely certain. "Our observations cannot yet completely exclude other potential atmosphere scenarios for TRAPPIST-1 d which were predicted in the literature," the authors explain, noting that other research involving climate models hints at the possibility that the tidally-locked planet could form high-altitude water clouds at its terminator, blocking atmospheric absorption signals from view.
But what about the other planets in the system?
“All hope is not lost for atmospheres around the TRAPPIST-1 planets,” Piaulet-Ghorayeb said. “While we didn’t find a big, bold atmospheric signature at planet d, there is still potential for the outer planets to be holding onto a lot of water and other atmospheric components.”
However, the outer planets aren't the juicy scientific targets that planet d is. They're further from the star, and colder. Even the JWST's powerful instruments struggle in those conditions. While detailed spectra aren't available for those worlds, the researchers still reached some conclusion.
"We find that even complete atmosphere loss for TRAPPIST-1 d would not preclude atmosphere presence for the outer HZ planets TRAPPIST-1 e, f, and g," the authors write in their conclusion. Contrary to the inner planets, it's possible that these outer planets held onto their water "even if they initially accreted only a few Earth oceans of volatiles."
“Our detective work is just beginning. While TRAPPIST-1 d may prove a barren rock illuminated by a cruel red star, the outer planets TRAPPIST-1e, f, g, and h, may yet possess thick atmospheres," added Ryan MacDonald, a co-author of the paper, now at the University of St Andrews in the United Kingdom, and previously at the University of Michigan. “Thanks to Webb we now know that TRAPPIST-1 d is a far cry from a hospitable world. We're learning that the Earth is even more special in the cosmos."
Being a human being means bearing witness to humanity's greatest, most triumphant moments of accomplishment and unity, but also to the depraved actions we take against one another. The minds of thinking people are bound to wonder if there are other worlds out there that host life. Each potentially habitable world is a glimmer of hope that humans, with all their struggles, are not the only intelligent species out there.
If we look to the heavens, and to exoplanets, for some kind of reprieve from humanity's troubles, TRAPPIST-1 d won't provide it. If this research is correct, its stricken from the list of hope-inspiring exoplanets.
NASA computer generated image of debris objects in Earth orbit, c. 2005
The numbers paint a stark picture of our orbital traffic problem. More than 11,000 active satellites currently circle Earth, with thousands more planned for launch in coming years. Even more concerning are the over 1.2 million pieces of space debris larger than one centimetre hurtling through space at incredible speeds. At those velocities, even a paint chip can damage a spacecraft, while larger debris can destroy entire satellites.
This growing congestion has turned collision avoidance into a daily headache for satellite operators worldwide. Currently, teams of specialists must manually assess threats, calculate risks, and coordinate with other operators when collisions seem likely. This process is time consuming, labor intensive, and prone to communication breakdowns that can complicate emergency responses.
That is where CREAM comes in, it aims to revolutionise this chaotic process by automating most collision avoidance activities. The system can evaluate potential crashes, generate precise manoeuvre plans, and support decision making with minimal human intervention. Think of it as an air traffic control system for space, but with artificial intelligence handling much of the complex coordination.
The launch of yet more satellites into Earth orbit onboard a Falcon 9 rocket delivering 60 Starlink satellites to orbit on November 11, 2019.
(Credit : US Air Force)
One of CREAM's most innovative features is its ability to connect different types of organisations involved in space operations. Satellite operators, space monitoring services, regulators, and observers can all communicate through the system, streamlining what was previously a fragmented and often frustrating process.
The system goes even further by facilitating negotiations between operators when potential collisions involve two active satellites rather than debris. If operators disagree on the best solution, CREAM can refer the dispute to mediation services, ensuring fair and transparent resolution.
Currently, CREAM exists as a ground-based prototype system developed by GMV and Guardtime. This version can already provide collision alerts and generate actionable avoidance manoeuvres that ground crews can implement. However, the real breakthrough will come when CREAM moves into orbit itself.
View of an orbital debris hole made in the panel of the Solar Max satellite
(Credit : NASA)
The project is preparing for expanded pilot testing while simultaneously developing space based versions. These include "piggyback missions" where CREAM will ride aboard other spacecraft as a digital payload, plus a dedicated demonstration mission to test the system's capabilities in the harsh environment of space.
Beyond preventing immediate collisions, CREAM addresses a fundamental challenge in space governance. Establishing "rules of the road" for space traffic has always faced a chicken and egg problem; you need both international agreement on the rules and the technology to enforce them.
CREAM provides that missing technological foundation. The system offers standardised tools that help operators follow best practices while giving regulators ways to monitor compliance. Its flexible design allows non-technical users to update standards and rules as international norms evolve. This adaptability ensures CREAM will remain relevant as space technology advances and new challenges emerge. Rather than becoming obsolete, the system can grow and adapt alongside our expanding presence in space.
The 3I/ATLAS object has become a real sensation in modern astronomy. Most scientists agree that it is a comet that has come to us from another star. Many popular publications write that it is even more interesting, because it may turn out to be an alien probe. Let’s figure out what’s what.
3I/ATLAS
Interstellar guest
On July 1, 2025, the ATLAS robotic telescope system discovered an object beyond Jupiter’s orbit that was moving quite rapidly against the backdrop of stars. Such behavior typically indicates a comet that has originated from the Oort cloud, located at the outskirts of the Solar System. However, no cometary activity was detected at first.
However, the speed and trajectory of this object immediately made it one of the major astronomical sensations of 2025, and soon even people who were far removed from observing the sky began to talk about it. It turned out that the comet, which was soon named 3I/ATLAS (C/2025 N1), had flown in from interstellar space.
The “3I” in the name indicates that this is the third macroscopic interstellar object known to humans. The first two were the asteroid Oumuamua (1I/ʻOumuamua) and the comet Borisov (2I/Borisov), discovered in 2017 and 2019, respectively. The fact that interstellar visitors were not recorded before, but now appear so abundantly, may frighten some people. But in reality, there is nothing mystical about it.
Over the past few decades, astronomical technology has advanced rapidly, with the emergence of large survey telescopes, space observatories, robotic instruments, and a network of enthusiasts who constantly exchange information on the Internet. Humanity has reached a level of observation where it can see things in the sky that previously went unnoticed.
Borisov comet. Source: Wikipedia
So, the appearance of the third interstellar object was eagerly awaited. Immediately after the announcement of the discovery of 3I/ATLAS, several powerful astronomical instruments were directed at it, thanks to which scientists were able to establish fairly quickly that it was indeed a comet and learn enough about it.
Comet characteristics
The first thing that interested scientists in 3I/ATLAS were its speed. In the Oumuamua and Borisov comets, it was significantly higher than in bodies with aphelion somewhere at the edge of the Solar System: 26 and 32 km/s, respectively.
However, in the case of 3I/ATLAS, this value was already 58 km/s at the moment when it entered the Solar System. That is, even then, it was flying a distance equal to the distance from Earth to the Sun in about a month. And this speed has only increased since then because now the gravity of our star acts on this body.
An interstellar comet in a photograph taken on July 2. Source: Wikipedia
Such high speed determined the trajectory, which turned out to be too unusual for objects in the Solar System. Its eccentricity is 6.141. Some may say that eccentricity cannot exceed unity. But this only applies to closed elliptical orbits, which are possessed by all bodies that constantly revolve around the Sun.However, eccentricity is also present in parabolic and hyperbolic trajectories, and the latter includes the orbit followed by 3I/ATLAS. Moreover, its eccentricity is so great that the trajectory resembles a straight line rather than a curve.
The second feature of 3I/ATLAS that caught the attention of scientists is the section of the sky from which the comet came to us. It is located in the constellation Sagittarius, close enough to the center of the Milky Way. At the same time, it has a sufficiently high vertical velocity component relative to the plane of our Galaxy’s disk, meaning that the comet flies through it rather than moving within it all the time.
The section of the sky where 3I/ATLAS was discovered. Source: Wikipedia
All this indicates that it originated near a star in the thick disk of the Milky Way. And they, as a rule, belong to the most ancient generations of stars. It was from this that perhaps the most sensational statement about 3I/ATLAS was derived, which is considered scientifically true and recognized by most scientists. This interstellar comet is older than the Sun. Its age is estimated to be between 7.6 and 13 billion years, although there is another estimate that it formed somewhere between 3 and 11 billion years ago.
In addition, throughout July, scientists observed 3I/ATLAS and confirmed that it exhibits normal cometary activity, i.e., it forms a coma and something resembling a tail. This, in turn, allowed them to conduct spectroscopic studies and confirm that it consists mainly of water and contains hydroxyl ions, OH. In addition, carbon dioxide and carbon monoxide were found on it, and it seems that their evaporation is responsible for the formation of the comet’s shell.
However, cyanides, oxygen, or complex organic molecules, which are found in comets that constantly revolve around the Sun, have not yet been detected in 3I/ATLAS. Instead, there is a lot of dust, and its particles are quite large, with a diameter of about 1 micron.
There is one interesting fact about 3I/ATLAS related to dust. When archival images from various telescopes were examined, an interstellar comet was found in images taken by the TESS satellite in May of this year. It operates in the infrared range, and its images show that this celestial body, even then, far beyond Jupiter’s orbit, was ejecting matter containing dust.
Image 3I/ATLAS taken by the Hubble Telescope. Source: Wikipedia
Finally, scientists were able to calculate the diameter of the comet’s nucleus with some accuracy. In early studies, it was estimated to be between 10 and 20 km. Then, thanks to the Hubble Space Telescope, it was reduced to a range of 0.32 to 5.6 km. But scientists disagree on whether its size is closer to the upper or lower limit. Some studies show that the nucleus is less than a kilometer in diameter, while others show that it is larger.
Aliens
It would be surprising if the appearance of 3I/ATLAS did not spark rumors that it was an alien spacecraft. This idea was expressed on social media almost from the very first days after the discovery, and on July 16, a certain Avi Loeb, a real professor of astrophysics at Harvard University, joined the discussion. He published an article in which he presented several entirely scientific arguments in favor of the idea that it could be an interstellar probe from aliens.
Of course, this sparked a flurry of publications speculating that this was a real alien spacecraft and that we should expect aliens to land in late autumn. Loeb has a rather scandalous reputation in academic circles: he has many high-quality scientific works to his credit, but he often makes overly bold predictions that are mostly unconfirmed.
The alien probe would not be much larger than Voyager-1. Source: www.space.com
After such a sensational statement, other scientists rushed to refute the words of Loeb and his colleagues. Their assumptions were mainly based on the fact that the orbit of 3I/ATLAS lies almost in the plane of the ecliptic, so it will pass close enough to several inner planets, which may indicate plans to explore them or even land on them.
In addition, Loeb stated that the object did not exhibit classic cometary activity. He was reasonably told that at the time of his statements, the object was far enough away from us that we could not see any emissions from it. Indeed, 3I/ATLAS subsequently showed quite standard cometary activity.
In addition, scientists pointed out that if it were an extraterrestrial probe, it would be a small metal object that we would see, at best, as it approached Mars’ orbit, but certainly not at a distance greater than 4 AU.
As for the comet’s orbit, although it is close to the ecliptic, it is still inclined at an angle of 5° relative to it, which may well be a coincidence. In general, its passage within the system deserves separate consideration.
Orbits of the Sun and 3I/ATLAS around the center of the Galaxy. Source: Wikipedia
Comet flight
Speaking about the possibility that there are aliens on 3I/ATLAS, it is important to note that at the moment of its closest approach to the Sun, Earth will be on the other side of it. Therefore, to approach it, a hypothetical alien spacecraft would have to detach itself from the ice mountain and perform a braking maneuver.
Many of those who like Loeb’s hypothesis says that all the prerequisites are in place because the comet’s trajectory is such that it will approach several large planets at once, and it will be possible to perform a gravitational maneuver near them.
However, let us consider what these approaches will look like. The first object on the path of 3I/ATLAS will be Mars. The comet will approach it at a minimum distance of 29 million kilometers. This is 75 times the average distance from Earth to the Moon. This is somewhat excessive for a gravitational maneuver.
Then, on October 29, 3I/ATLAS will pass through perihelion – the point closest to the Sun. At that time, it will be 1.36 AU away from the Sun. This means that it will be inside the orbit of Mars, but still very far from the orbit of our planet, which at that moment will be on the other side of our star.
Shortly after that, on November 3, the comet will pass at its closest distance to Venus, but that will still be 97 million km away. Earth regularly comes much closer to our neighbor. What gravitational maneuvers can be expected in this case remains unknown.
After that, Earth will appear in front of 3I/ATLAS, which will already be moving away from the Sun. The maximum approach will occur on December 19, and the distance will be 1.8 AU, which means that the interstellar visitor will be much farther away from us than the Sun. Finally, on March 16, 2026, 3I/ATLAS will approach a planet that could give it a nice gravitational maneuver – Jupiter. However, this will happen after it has flown through the entire inner Solar System and will have to turn back and catch up with Earth, which at that time will again be on the opposite side of the Sun from it. And the distance from the gas giant will be 53 million km. Which is quite a lot.
The 3I/ATLAS movement across the starry sky. Source: Wikipedia
Of course, we can assume that the aliens’ spaceship will detach from it precisely during its approach to Mars, or during its passage through perihelion when we cannot see it. In this case, it will have to slow down by more than 20 km/s.
And even so, this will not help the aliens much, because the trajectory will remain retrograde relative to the direction of the planets’ rotation around the Sun. So, if the aliens who flew to us billions of years ago have a plan that is a little more complicated than becoming kamikaze pilots, they will have to slow down again, spending a lot of energy on it. And the aliens still need to get that energy from somewhere.
So, most likely, we should not expect any extraterrestrial visitors at the end of the year. And we will not be able to admire the interstellar comet itself. By the time it emerges from behind the Sun, its brightness will already be approximately 11 stellar magnitudes, meaning it will be inaccessible even to small amateur instruments, let alone the naked eye.
And it will not be possible to launch a spacecraft to study it up close. Calculations show that to catch up with it, it would have to launch from Earth, and this would be a mission at the limit of our capabilities in terms of accelerating spacecraft. Better yet, it would have to launch from Mars’ orbit.
But scientists continue to study 3I/ATLAS. Now we can be sure that it is not the last one, and in a few years, we can expect the next interstellar visitor. And perhaps by then, we will be able to prepare a device that will take a closer look at it.
Illustration of a giant star being torn apart by a black hole. Credit: CfA
Supernova SN 2023zkd was discovered in July 2023 using the Zwicky Transient Facility telescope in California. Artificial intelligence, which analyzes data on stellar explosions on a daily basis, marked it due to its unusual behavior.
“The open supernova had two strange features. First, it seemed to explode twice: first it became brighter, then dimmed, and then flared up again. Secondly, supernovae usually reach their peak brightness in a matter of days or weeks, but in this case, the star gradually became brighter over several years before exploding,” said lead author Alexander Gagliano.
Death dance with a black hole
Researchers suggest that the strange behavior can be explained by the star falling into the gravitational trap of a black hole. Two objects began to approach each other, causing enormous gravitational stress, which led to the premature explosion of the star.
There is another scenario: perhaps the black hole completely tore the star apart before it had a chance to explode on its own. In this case, the stellar debris collided with the gas surrounding the black hole, triggering a flare.
How artificial intelligence helps find anomalies
The LAISS system, which detected SN 2023zkd, analyzes data on the luminosity of supernovae and their galaxies, comparing them with known samples. If something unusual is found, a specially configured bot notifies scientists.
“It’s an incredible instrument for finding rare phenomena,” says Gagliano. Thanks to such technologies, astronomers are discovering more and more exotic cosmic events.
The discovery of SN 2023zkd is just the beginning. Studying such supernovae will help us better understand how stars and black holes interact.
Scientists have created a specialized AI assistant that will help in the study of Earth and other planets. It is capable of receiving data from geophysical instruments and using it to construct graphs and make assumptions. At the same time, requests can be made to it in normal human language.
AI will help study processes on Earth and other planets. Source: phys.org
AI for scientists
The new generation of AI has long sparked debate about whether it can really help people acquire new knowledge, or whether it is simply capable of stringing letters together to form words. But it seems that researchers at the University of Hawaii at Manoa have the answer to this question.
They created the Intelligent Data Exploring Assistant (IDEA) software platform, which combines the functionality of large language models such as ChatGPT with the capabilities of specialized neural networks designed to analyze large scientific data sets.
Based on IDEA, it is possible to create a variety of assistant instruments capable of understanding questions in plain language, analyzing queries based on data sets from various measuring devices, and generating graphs and assumptions that will provide scientifically agreed answers to scientists’ questions.
Earth and beyond
First and foremost, the platform is designed for studying Earth as a planet. Based on IDEA, scientists were able to create a prototype of the Station Explorer Assistant (SEA) and applied it to analyze data from tide gauges — instruments that measure sea level with high accuracy. Usually, special programs need to be written to process data from them, but the new AI has already demonstrated its ability to provide answers without this.
Researchers say that it is not perfect, still makes mistakes, and its work needs to be carefully monitored. But it still makes the work of scientists much easier. And this applies not only to oceanographic data.
Although SEA focuses on sea level data, the basic structure of IDEA is designed to work across a wide range of geological scientific disciplines. In one example from the study, researchers applied IDEA to atmospheric data from Mars — an area they had never worked with before — and were surprised at how easily the assistant adapted to the new dataset with only a change in instructions and data sources.
Although SEA is still a prototype, it is available online for scientists or university students to test and try out. Developers are encouraged to familiarize themselves with the IDEA framework on GitHub and experiment with adapting it to their own data or using other large language modeling services.
Scientists are pondering the nature of 300 mysterious objects that the James Webb Space Telescope has spotted in the depths of space. Most likely, these are incredibly bright young galaxies, but this assumption still needs to be verified.
Scientists from the University of Missouri are discussing whether the bright objects recorded in large numbers by the James Webb Space Telescope could be distant but bright galaxies, or something else.
In the first few years of operation, the new space observatory saw many more objects than any telescope. This led to a problem with sorting all the objects it discovered. Initially, 300 of them simply could not be classified.
“These mysterious objects are candidate galaxies in the early universe, meaning they could be very early galaxies,” said Haojing Yan, a professor of astronomy at the College of Arts and Sciences at Mizzou and co-author of the study. “If even a few of these objects turn out to be what we think they are, our discovery could challenge current ideas about how galaxies formed in the early universe—the period when the first stars and galaxies began to take shape.”
But identifying objects in space does not happen instantly. This requires a careful, step-by-step process to confirm their nature, combining advanced technology, detailed analysis, and several space detective investigations.
Step 1: Identifying the first clues
Mizzou’s researchers used two powerful infrared cameras on the JWST: the Near Infrared Camera and the Mid-Infrared Instrument. Both devices are specially designed to detect light from the most distant corners of space, which is key to studying the early Universe.
Why infrared? Because the farther away an object is, the longer its light travels to reach us. As light from these early galaxies travels through space, it stretches into longer wavelengths — shifting from visible light to infrared. This stretching is called redshift, and it helps us determine how far away these galaxies are. The higher the redshift, the farther the galaxy is from Earth, and the closer it is to the beginning of the Universe.
Step 2: “ The dropout”
To identify each of the 300 candidates for early galaxies, researchers at Mizzou used a well-known method called the “dropout” technique.
This method detects galaxies with high redshifts by examining objects that appear in redder wavelengths but disappear in bluer ones — a sign that their light has traveled vast distances and time. This phenomenon is an indicator of the “Lyman Break” — a spectral feature caused by the absorption of ultraviolet light by neutral hydrogen. As the redshift increases, this signal shifts toward redder wavelengths.
Step 3: Estimating the details
Once the “dropout” technique identifies each of the galaxy candidates, the next step is to check whether they could be at very high redshifts, Yan said.
“Ideally this would be done using spectroscopy, a technique that spreads light across different wavelengths to identify signatures that would allow an accurate redshift determination,” he said.
However, when complete spectroscopic data are not available, researchers can use a technique called spectral energy distribution fitting. This method provided Sun and Yan with a basis for evaluating the redshifts of their candidate galaxies, as well as other properties such as age and mass.
In the past, scientists commonly believed that these extremely bright objects were not early galaxies, but rather something that mimicked them. However, based on their achievements, Sun and Yan believe that these objects deserve closer attention and should not be dismissed so quickly.
Step 4: Final answer
The final test will use spectroscopy — the gold standard — to confirm the team’s findings.
Spectroscopy separates light into different wavelengths, just as a prism separates light into a rainbow of colors. Scientists use this technique to detect the unique fingerprint of a galaxy, which can tell them how old the galaxy is, its formation and composition.
“One of our objects is already confirmed by spectroscopy to be an early galaxy,” Sun said. “But this object alone is not enough. We will need to make additional confirmations to say for certain whether current theories are being challenged.”
Researchers from the Max Planck Institute for Radio Astronomy have obtained a detailed image of an object resembling the Eye of Sauron from “The Lord of the Rings.” The shot helped reveal its long-held secret.
The cosmic “Eye of Sauron.” Portrait of the blazar PKS 1424+240, obtained by the VLBA radio telescope. Source: Y.Y. Kovalev et al.
The object captured in the photo is known as PKS 1424+240. It is located billions of light years from Earth and is a blazar — a galaxy with a supermassive black hole at its center that actively absorbs matter. The jet it produces is directed toward us, which makes it appear much brighter than usual.
PKS 1424+240 has long puzzled astronomers. It stands out as the brightest of the known blazars emitting neutrinos, and is also a source of very high-energy gamma rays. However, strangely enough, its radio jet moves slowly, which contradicts models according to which only very fast jets can be the source of such powerful radiation.
Now, thanks to 15 years of super-precise radio astronomical observations using the VLBA radio telescope, researchers have been able to create a detailed image of this jet with unprecedented resolution. It showed an almost perfect toroidal magnetic field with a jet directed straight at us.
Illustration showing the position of the jet of blazar PKS 1424+240 relative to Earth. Source: NSF/AUI/NRAO/B. Saxton/Y.Y. Kovalev et al.
Since the jet is directed almost exactly toward Earth, its high-energy radiation is significantly amplified by the effects of special relativity. This alignment results in a brightness increase of 30 times or more. At the same time, the jet appears to move slowly due to projection effects — a classic optical illusion.
This geometry allowed scientists to look directly into the heart of the blazar jet — an extremely rare opportunity. Polarized radio signals helped the team map the structure of the jet’s magnetic field, revealing its probable spiral or toroidal shape. This structure plays a key role in launching and collimating the plasma flow and may be necessary for accelerating particles to extreme energies.
According to scientists, solving this mystery confirms that active galactic nuclei with supermassive black holes are not only powerful accelerators of electrons, but also protons — sources of the observed high-energy neutrinos.
This discovery is a triumph for the MOJAVE program, under which VLBA has been monitoring relativistic jets in active galaxies for decades. Scientists use very long baseline interferometry (VLBI) technology, which connects radio telescopes around the world to form a virtual telescope the size of the Earth. This provides the highest resolution available in astronomy, allowing us to study the smallest details of distant cosmic jets.
While the American President aims to shut down NASA greenhouse gas monitoring missions, European scientists are figuring out how to use ground-based astronomical telescopes to fill the gap. Image Credit: ESA
Our powerful, modern, ground-based telescopes have to deal with a lot of noise in the starlight they observe. The noise comes from Earth's atmosphere, which forces telescopes to use solutions like adaptive optics to filter it out. Researchers at the University of Warwick in the UK, in partnership with Spanish institutions, are developing a method to use that noise to measure greenhouse gases (GHGs) in Earth's atmosphere.
Earth's atmospheric carbon won't just disappear if we stop measuring it. More and more carbon is accumulating in the atmosphere and the effects of that carbon are felt in our warming world. There are many different ways to measure that carbon and determine how it affects different parts of the world, and how it affects agriculture, drought, receding ice, and forest fires. Since we have so many telescopes operating around the world, maybe they can contribute to these measurements.
When observing distant objects, astronomers often use spectroscopy to determine the chemical contents of exoplanet atmospheres, stars, and other objects like gas clouds. All molecules have spectroscopic fingerprints that reveal their presence. Telluric contamination is the effect that Earth's atmospheric molecules have on the starlight observed by telescopes. It introduces telluric lines into observations that make the signal from distant objects noisy. They can mask or mimic the spectroscopic lines from the target object.
A PhD student in the Astronomy and Astrophysics group at Warwick University, Marcelo Aron Fetzner Keniger, has developed a way to use these contaminating telluric lines to measure GHGs. It's called Astroclimes, and it can measure molecules like methane, carbon dioxide, and water vapour in our planet's atmosphere.
“Monitoring the abundance of GHGs is necessary to quantify their impact on global warming and climate change," Keniger said in a press release. "Using telluric lines to measure the abundance of GHGs in the Earth’s atmosphere has been extensively employed using solar spectra, for example by the COllaborative Carbon Column Observing Network (COCCON). However, since they rely on solar spectra, these measurements can only be carried out during the day, so Astroclimes can hopefully fill the gap with nighttime measurements.”
This is a plot from the Astroclimes algorithm showing Telluric lines.
Image Credit: Marcelo Aron Fetzner Keniger/University of Warwick
The University of Warwick collaborated with Calar Alto Astronomical Observatory (CAHA) in Almería, Spain, the University of Almería and the Spanish State Meteorological Agency (AEMET on an observing campaign in July to test Astroclimes. The goal was to show how combining night-time observations of stars with Astroclimes with day-time observations of the Sun can help scientists study Earth's carbon cycle and the role that GHGs play.
"Astroclimes can measure the abundance of greenhouse gases on Earth by generating a model telluric transmission spectra and fitting it to the spectra of telluric standard stars in the near-infrared taken by ground-based telescopes," Keniger said in a presentation to the Royal Meteorological Society.
CAHA hosts several telescopes, including a 3.5 meter telescope with the CARMENES (Calar Alto high-Resolution search for M-dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs). CARMENES was used with the Astroclimes algorithm during nighttime observations, while a temporary, portable FTIR spectrometer (EM27/SUN) from the COCCON-Spain network was used during the day. The COCCON instrument can measure GHG concentrations and calibrate the readings from CARMENES.
“If we can successfully calibrate Astroclimes with the help of COCCON measurements, it could provide a new network for measuring GHG abundances, complementing current networks with nighttime measurements," Keniger said.
It's not a simple task, though. Telluric lines not only change due to different GHGs; changing temperature, humidity, and pressure can also alter them.
This image shows the EM27/SUN instrument of the COCCON-Spain network observing the Sun, almost in the direction of the CAHA 3.5 m telescope.
Image Credit: Calar Alto Observatory (CAHA)
EM27/SUN is at about 2,100 meters in altitude, and its measurements were combined with an instrument at sea level at the University of Almería (UAL). Joaquín Alonso Montesinos is a Professor at UAL and is the representative of the UAL in the COCCON-Spain project. Montesinos said, “We are grateful to AEMET for counting on us for such an important project, which we believe will be a benchmark in the energy transition.”
The COCCON-Spain project is intended to be an integrated GHG observation system for the country. There is a gap in the observation of GHGs in Spain, and COCCON aims to fill that gap. Initially, it will consist of 12 stations that measure background GHG concentrations as well as concentrations near major urban/industrial greenhouse gas emission zones.
“The COCCON-Spain national network aims to address the latent lack of atmospheric GHG observations in Spain through the implementation of a network of stations for measurement on a national scale. One of the main objectives of the COCCON-Spain network is to improve current knowledge of GHG sources and sinks, thus contributing to the development of mitigation and adaptation strategies for climate change,” said Omaira García-Rodríguez (AEMET-CIAI), coordinator of the network.
COCCON and Astroclimes dovetail nicely with the Calar Alto observatory. Observatories are typically placed in environments that are isolated and not connected to power grids. In Calar Alto's case, it burns diesel to generate electricity and heat water, generating more than 100 tons of CO2 annually. The observatory is turning itself into a low-carbon energy island with the addition of solar panels and a biomass boiler to replace diesel fuel.
Aerial view of the Calar Alto Observatory from the north at the telescope domes. From left to right: the 2.2-m telescope, the Spanish 1.5-m telescope (in the foreground), the 1.2-m telescope, the Schmidt-reflector and the dome of the 3.5-m telescope with a height of 43 m. In the background the coast of Almería is seen.
Credit: MPIA
"Due to the peculiar characteristics of the environments surrounding professional astronomical observatories, the costs in fuel and electricity are high" said Jesús Aceituno, director of the observatory and principal investigator of the project. "By implementing the Calar Alto energy island, we pretend to be a world reference for other professional observatories as a management model that helps the environment, with an estimated reduction of a hundred and sixty tons of carbon dioxide per year and the resulting optimization of the associated costs".
“Calar Alto, with its photovoltaic plant and biomass boiler, aims at reaching energy sustainability. These greenhouse gas detections made with CARMENES demonstrate that an astronomical observatory can also serve to monitor our planet's climate,” said Aceituno.
Images of 3I/ATLAS captured by Swift. Credit - Z. Xing et al.
3I/ATLAS, our third discovered interstellar visitor, has been in the news a lot lately for a whole host of reasons, and rightly so given the amount of unique scientific data different groups and telescopes have been collecting off of it. A new pre-release paper from researchers at the Auburn University Department of Physics recounts yet another interesting aspect of the new visitor - its water content.
Almost all comets have some amount of water in them, as water is one of the most common substances in the universe, despite its absence on many of the worlds of our solar system. Typically, comets have a “coma” of water particles trailing behind them as they approach the Sun. Doing so heats up the particles, sublimating them into water vapor, which then streams behind the comet, giving it its iconic “tail”.
But 3I/ATLAS is acting differently from other comets, to say the least. It was around 6 AU at its discovery, but has been making its way closer to the Sun on its one-way journey, which will eventually peak at around 1.3 AU in October. The Auburn astronomers observed it at the end of July, about a month after it was first discovered, and when it was 3.5 AU away from the Sun.
Fraser discusses the newest interstellar object - 3I/ATLAS
They did so using the Ultraviolet / Optical Telescope (UVOT) on the Neil Gehrels-Swift Observatory, which is in orbit above Earth and therefore easier to detect faint photometric lines from things like water. Typically, astronomers wouldn’t expect to find OH (hydroxyl) emissions, which they use as a proxy for water, as far out as 3.5 AU, since the water ice sublimation process isn’t very effective at that distance.
To their surprise, not only did they see a strong OH signal, they also didn’t see any signal of the cyanogen radical (CN), which is almost always one of the first signals found on a comet. That is due to its low sublimation point (around -13 C) and emission band in at a wavelength that easily passes through our atmosphere. However, its lack of detection in this round of observations could mean that the composition of 3I/ATLAS is dramatically different from other comets in our solar system.
Another useful statistic to come out of the water observations is an estimate of the “active surface area” of the comet - essentially an estimate of how much of the comet’s area is actively producing water. The authors calculated approximately 19 km2 of active surface on 3I/ATLAS. Given that the upper limit of the diameter of the comet is 2.8 km, that means that around 20% of the surface area of the comet is actively producing water vapor. That is 4 times higher than the typical 3-5% of solar system’s cometary population, and might be explained by the fact that this is likely the first time 3I/ATLAS is actually visiting a star itself, so it has more water to expel.
Fraser discusses the possibility of catching up to an interstellar object.
That amount of water is key to the next observational step suggested by the authors. They developed two hypotheses, which can each be confirmed as the comet reaches perihelion. If the water production peaks near perihelion, and only trace amounts of “high-metallicity” volatiles like carbon monoxide and cyanogen, that would indicate that 3I/ATLAS is from a “low-metallicity” system (i.e. one where there is only a large amount of hydrogen, and not many other elements). On the other hand, if the water production rate drops off significantly after perihelion, and is replaced by a significantly increased volatile production rate, this would indicate that it actually came from a high-metallicity system, and it would have more in common with the last interstellar visitor - 2I/Borisov.
Given the attention from both scientists and the wider public this comet has drawn, it will undoubtedly be observed as closely as possible over the coming months while it is still visible. With even more new hypotheses to test, 3I/ATLAS will help broaden our understanding of its origins as it begins to melt more. The world will be watching as it does.
The galaxy found to be hosting FRB 2020304B. The top left image shows the field of view surrounding the observation region, with the NIRcam footprint shown on the right. The square shows the NIRSpec IFS observation footprint, and the most likely position of FRB 2020304B shown as a green cross surrounded by the localisation uncertainty (white circle). The middle images show, from left to right, the author’s NIRCam observations, Oxygen III data from NIRSpec, Hydrogen alpha data from NIRSpec, and a white light image from NIRSpec. The bottom panel shows the spectrum (black line) and its uncertainties (shaded region) of the host galaxy (Credit : South African Radio Astronomy Observatory)
Fast radio bursts (FRBs) last around a millisecond and in doing so encode otherwise unattainable information on the plasma which permeates our Universe, providing insights into magnetic fields and gas distributions. In a paper authored by Manisha Caleb from the University of Sydney, the team report upon the discovery of FRB 20240304B which lies at a redshift of 2.148 +/- 0.001 corresponding to just 3 billion years after the Big Bang.
The burst, designated FRB 20240304B, was first detected on March 4, 2024, by South Africa's MeerKAT radio telescope array. What makes this discovery extraordinary is its incredible distance, at a whopping redshift of z = 2.148±0.001, or about 3 billion years after the Big Bang. This means we're observing light that traveled for over 11 billion years to reach Earth.
Artist illustration of the MeerKAT Radio Telescope
Finding the source of the signal required detective work across multiple observatories. The authors attempt to locate FRB 20240304B's host galaxy using ground based observatories and archival data but this came up short. However, follow ups with JWST's NIRCam and NIRSpec instruments succeeded in revealing the FRB's host galaxy and obtaining a spectroscopic redshift.
NIRCam being installed in 2014
(Credit : Chris Gunn)
The burst of radio waves travelled through space and as it does it disperses at a rate of approximately 2,330 pc cm⁻³, immediately suggesting an extremely distant origin. This measurement more accurately describes how much the radio signal was stretched and delayed by free electrons in space, acting like a fingerprint that reveals the vast distances the signal traveled.
This discovery doubles the redshift reach of localised FRBs and probes ionised baryons across ~80% of the history off the universe. Previous FRB detections had only reached back about halfway through cosmic time, but FRB 20240304B pushes our observational boundary to when the Universe was still in its youth. The host galaxy itself tells an interesting story. FRB 2024030 was detected with the MeerKAT radio telescope in South Africa and localised the signal to a low-mass, clumpy, star forming galaxy using the James Webb Space Telescope. This young, actively star-forming galaxy provides crucial clues about the origins of these mysterious bursts.
Since its host galaxy is relatively young, not very massive, and still forming stars, the presence of a FRB suggests an origin which can occur over relatively short timescales, such as young magnetars. This supports theories that FRBs originate from highly magnetised neutron stars called magnetars, rather than from processes requiring billions of years to develop.
Host galaxies of fast radio bursts
(Credit : NASA/Hubble Space Telescope)
The discovery also reveals complex magnetic field structures spanning gigaparsec scales. Its sightline, with the Virgo Cluster and a foreground group, reveals magnetic field complexity over many gigaparsec scales. As the radio waves traveled to Earth, they passed through various structures, each leaving its signature on the signal.
Perhaps most remarkably, the observations establish FRB activity during the peak of star formation and demonstrate that FRBs can probe galaxy formation during the most active era in cosmological history. The epoch when FRB 20240304B originated corresponds to when the Universe was forming stars at its most furious rate, a period astronomers call "cosmic noon."
As next generation telescopes come online, discoveries like FRB 20240304B point toward an exciting future where these fleeting signals become messengers from the universe's distant past, helping us understand how the universe evolved from its early, chaotic youth into the structured cosmos we see today.
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Over mijzelf
Ik ben Pieter, en gebruik soms ook wel de schuilnaam Peter2011.
Ik ben een man en woon in Linter (België) en mijn beroep is Ik ben op rust..
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