Earth Had Ring System 466 Million Years Ago, New Research Suggests

Breakup of an asteroid passing within Earth’s Roche limit likely formed the debris ring during the middle Ordovician period, according to new research from Monash University.

Tomkins et al. suggest that a large chondrite asteroid had a near miss encounter with Earth 466 million years ago, which caused it to break up as it passed through Earth’s Roche limit.

All large planets in our Solar System have rings, and it has been suggested that Mars may have had a ring in the past.

This raises the question of whether our home planet also had a ring system in the past.

In new research, Monash University’s Professor Andy Tomkins and his colleagues examined the positions of 21 asteroid impact craters from a 40-million-year period of enhanced meteor impact cratering known as the Ordovician impact spike.

All these craters are located within 30 degrees of the equator, despite over 70% of Earth’s continental crust being outside this region, an anomaly that conventional theories cannot explain.

The researchers believe this localized impact pattern was produced after a large asteroid had a close encounter with Earth.

As the asteroid passed within Earth’s Roche limit, it broke apart due to tidal forces, forming a debris ring around the planet — similar to the rings seen around Saturn and other gas giants today.

“Over millions of years, material from this ring gradually fell to Earth, creating the spike in meteorite impacts observed in the geological record,” Professor Tomkins said.

“We also see that layers in sedimentary rocks from this period contain extraordinary amounts of meteorite debris.”

“What makes this finding even more intriguing is the potential climate implications of such a ring system,” he said.

The researchers speculate that the ring could have cast a shadow on Earth, blocking sunlight and contributing to a significant global cooling event known as the Hirnantian Icehouse.

This period, which occurred near the end of the Ordovician, is recognized as one of the coldest in the last 500 million years of Earth’s history.

“The idea that a ring system could have influenced global temperatures adds a new layer of complexity to our understanding of how extraterrestrial events may have shaped Earth’s climate,” Professor Tomkins said.

“The existence of such a ring, forming around 466 million years ago and persisting for a few tens of millions of years, could explain several puzzles in our planet’s past,” lead author Andrew G. Tomkins, a geologist at Monash University in Australia, writes in the Conversation.

• The team’s findings appear in the journal Earth and Planetary Science Letters.
• Andrew G. Tomkins et al. 2024. Evidence suggesting that Earth had a ring in the Ordovician. Earth and Planetary Science Letters 646: 118991; doi: 10.1016/j.epsl.2024.118991

{ https://www.sci.news/ }

20-09-2024 om 00:22 geschreven door peter  

Er is een radiosignaal uit de diepe ruimte op aarde aangekomen: het is 8 miljard jaar oud

door Janine

M. Kornmesser/Eso

Als we aan het heelal denken, stellen we ons een oneindige uitgestrektheid voor met een paar hemellichamen, maar voor het grootste deel helemaal leeg. Toch zit de ruimte, naast sterren en planeten, vol bewegende deeltjes, fotonen en elektromagnetische golven die enorme afstanden afleggen. Soms bereiken ze zelfs de aarde, zoals onlangs is ontdekt door een team van astronomen: het oudste radiosignaal dat ooit door de mens is vastgelegd en dat acht miljard jaar geleden ontstond. Laten we eens kijken waar het over gaat!

Het oudste en krachtigste radiosignaal ooit ontdekt

Na acht miljard jaar door de ruimte te hebben gereisd, werd het radiosignaal ontdekt door wetenschappers hier op aarde. Concreet moeten we ons een ongelooflijk krachtige lichtflits voorstellen die echter geen enkele seconden duurt, maar eerder een paar milliseconden of zelfs minder: het gaat om een Fast Radio Burst, oftewel snelle radio-uitbarsting. Dit zijn de woorden van Ryan Shannon, astrofysicus aan de Swinburne University of Technology en een van de auteurs van het onderzoek:

Dat is genoeg vermogen om een ​​kom popcorn van ongeveer twee keer de grootte van de zon in de magnetron te zetten. Het onderzoek bevestigt dat snelle radio-uitbarstingen veel voorkomende gebeurtenissen zijn in de kosmos, en dat we ze kunnen gebruiken om materie tussen sterrenstelsels te detecteren en de structuur van het universum beter te begrijpen.

Het onderzoek, gepubliceerd in het tijdschrift Science, stelt ook de vraag wat voor soort explosie zo'n FRB zou kunnen produceren, het oudste en krachtigste radiosignaal dat ooit is ontdekt. In minder dan een milliseconde gaf het signaal evenveel energie af als de zon in 30 jaar kan uitzenden.

Wat zijn snelle radioflitsen?

CSIRO/Wikimedia Commons - CC BY 3.0

De sleutel tot het begrijpen van het mysterie van het oudste en krachtigste radiosignaal dat ooit is ontdekt, zijn de snelle radio-uitbarstingen. Dit zijn raadselachtige fenomenen waarover we nog steeds niet veel weten: FRB 20220610A werd in juni 2022 onderschept door ASKAP-radiotelescopen in Australië. Vervolgens werden de gegevens verfijnd door andere telescopen in Europa en Zuid-Amerika om de oorsprong van het signaal te achterhalen.

De onderzoekers ontdekten vervolgens het gebied in de ruimte waar de snelle radioflits zou zijn ontstaan: het zou niet gaan om een enkel sterrenstelsel, maar om een hele cluster van sterrenstelsels die aan het samensmelten waren. Deze en andere FRB's zouden dus gekoppeld kunnen worden aan neutronensterren, extreem dichte objecten met een enorm magnetisch veld. In de praktijk zouden de snelle radioflitsen kunnen ontstaan door botsingen tussen neutronensterren en zwarte gaten, of door de aard van binaire stelsels waarin neutronensterren voorkomen.

Acht miljard jaar door het heelal

Zoals we in de inleiding al zeiden, is de ruimte helemaal niet leeg, hoewel het voor ons het tegenovergestelde lijkt. Er zijn niet alleen elektromagnetische golven en snelle radioflitsen, maar ook andere elementaire deeltjes, zoals bijvoorbeeld elektronen. Volgens Ryan Shannon kan het bestuderen van een FRB in de praktijk helpen om de materie die in de ruimte tussen sterrenstelsels is verspreid beter te begrijpen:

Zelfs in een bijna volledig lege ruimte kunnen snelle radioflitsen alle elektronen “zien”, waardoor we kunnen meten hoeveel materie er tussen sterrenstelsels is. Als we de hoeveelheid normale materie in het heelal tellen, de atomen waar we allemaal van gemaakt zijn, zien we dat meer dan de helft van wat er vandaag zou moeten zijn, ontbreekt.

De manier waarop deze FRB's interageren met de ruimte tussen sterrenstelsels kan ons dus veel meer vertellen over hoe de materie in het heelal verdeeld is. Dit is nog belangrijker als we bedenken dat de laatste snelle radioflits de oudste en krachtigste is die ooit is ontdekt: hij heeft acht miljard jaar door het heelal gereisd tot hij ons bereikte. En het gaat nog verder door.

{ https://www.curioctopus.nl/ }

19-09-2024 om 23:37 geschreven door peter  

The Big Bang started it all - but the 'Big Crunch' is what could wipe us out

• Is the 'dark energy' which fuels the expansion of the universe weakening?
• Another scenario sees stars 'blink out' one by one in a 'Big Freeze' 
•  READ MORE: How a 'Big Rip' could end the universe - 'everything goes wrong' 

By Rob Waugh and Matthew Phelan Senior Science Reporter For Dailymail.Com

While the 'Big Bang' is widely accepted as the cosmic event that started our entire universe, scientists warn there might just be a 'Big Crunch' that destroys it all.

As theorized, the 'Big Crunch' would be a horrific scenario whereby the universe's current process of expansion snaps into reverse — ending with galaxies, stars and planets all crashing into one another, as every last shred of matter collapses inward. 

But in the past year, scientists have discovered that 'dark energy,' a force proposed to explain what 'pushes' the cosmos to expand, may be becoming less 'pushy

'That means,' as one physics professor put it, 'revising our understanding of basic physics, our understanding of the Big Bang itself, and our understanding of the long-range forecast for the Universe.'

The Big Crunch could 'suck' the universe back in on itself. Above, a NASA animation still frame which depicts two neutron stars colliding, produced by NASA's Goddard Space Flight Center

TKTK. Above, a nighttime photo of the Dark Energy Spectroscopic Instrument (DESI) installed at the Kitt Peak National Observatory near Tucson, Arizona

For most people on Earth, the first signs of the Big Crunch would be in the sky, with galaxy clusters and galaxies merging, or stars beginning to collide with each other.

Telescopes would show that the cosmic microwave background (a fossil echo of the Big Bang) was warming up — and would soon reach thousands of degrees Celsius.

For comparison, the current temperature of this background microwave radiation is just under 3 degrees above 'absolute zero' or 'negative 273.15 degrees Celsius,' according to the European Space Agency (ESA), NASA and other experts.

Roughly 300,000 years after the Big Bang, this cosmic microwave background is estimated to have been 3,000 degrees Celsius; and farther back in time, closer to the Big Bang itself, NASA estimates that its heat was as high as 273 million degrees.

'At these high temperatures,' according to NASA's Wilkinson Microwave Anisotropy Probe team. 'hydrogen was completely ionized into free protons and electrons.'

In short, the forces which currently make the universe expand would fizzle out and the universe would fall in on itself, in an obscene reversal of the Big Bang.

All intergalactic matter would condense together with stars and planets sucked into a burning core where the surface of stars would ignite other celestial bodies.

Eventually, the universe itself would become a single, vast fireball, at least according to some astronomers and astrophysicists, with all living things incinerated, and time and space itself wiped out of existence.

The new data suggesting that the Big Crunch may, in fact, be the ultimate fate of our universe emerged from an incredible telescopic system on a modest mountain in Kitt Peak, Arizona — automated with the help of 5,000 tiny robots that reposition its fiber optic cables.

The Dark Energy Spectroscopic Instrument (DESI) is a telescope which has spent three years building a 3D map of the universe, including millions of galaxies, at a speed previously unheard of in astronomy thanks to its robotic systems.

Over the course of one recent record-setting night this year, February 12, 2024, DESI managed to document the locations of nearly 200,000 distant 'redshift' galaxies.

It was data like this, collected by DESI, that appears to suggest that the dark energy 'fuel' responsible for the steady expansion of our universe appears to be weakening.

'The entire cosmological community was really shocked,' according to ex-DESI team member Luz Ángela García Peñaloza, a cosmologist at Columbia's Universidad ECCI.

Physicsts current 'standard model' of how the cosmos works, its history, and how it has evolved is called the Lambda Cold Dark Matter (LCDM) model — and it rests on the assumption that dark energy remains constant throughout all time.

The 'Lambda' in the theory's name, in fact, comes from a constant value, one pairing both Einstein's 'cosmological constant' and the once-presumed-constant of dark energy, a presumption DESI data collected from the past 11 billion years seem upend.

Above, an image issued by Durham University depicts portions of DESI's validation as part of the 'One-Percent Survey.' Researchers took detailed sky images in 20 different directions, crafting a 3D map of 700,000 objects, about 1 percent of the total volume DESI plans to study

The new data suggesting that the Big Crunch may, in fact, be the ultimate fate of our universe emerged from DESI, an incredible telescopic system perched on a modest mountain in Kitt Peak, Arizona. Above, DESI installed inside the dome of the Kitt Peak National Observatory

'DESI saw that the "equation of state" of the universe isn't consistent with the usual LCDM model,' García Peñaloza told Space.com, 'but instead, it is showing a hint that dark energy is varying with time.'

'This was pretty surprising because most cosmological observations thus far have favored the LCDM model,' she explained. 

The shocking discovery, she added, 'open a window for variable dark energy models' meaning not just the possibility of a Big Crunch but for other odd outcomes as well.

First theorized in 1998, dark energy is a theoretical force which explains why the universe is expanding, and why that expansion is accelerating.

The idea of dark energy is that the vacuum of space possesses a tiny amount of energy of its own, so faint and difficult to measure that it was dubbed 'dark energy.'

But the hints coming from DESI suggest that not only is dark energy weakening, but there has been a process whereby it first got stronger, only then to slowly weaken.

'If dark energy isn't a strict constant, who knows how it evolves,' as astronomer Joan Najita with the National Science Foundation's NOIRLab said this year. 

'That uncertainty, and the potential unshackling from a cosmological constant,' she noted, 'opens a richer set of potential futures for us.'

Each point in this cross section of the DESI map represents one galaxy. The preliminary version of the DESI map (above) shows only 400,000 of the 35 million galaxies expected for final map

A slide through 3-D map of galaxies from the completed SDSS survey (left) and from the first few months of the DESI survey (right). The earth is at the centre, with the furthest galaxies plotted at distances of 10 billion light years

If the expansion of the universe continues, fueled by dark energy, another possible end will be almost as nightmarish - a scenario described as the 'Big Freeze', where as the universe expands relentlessly, eventually stars will stop forming.

Existing stars will run out of fuel, and stars travel further and further apart, leading to a lonely, dark universe as one by one the stars blink out.

From our Milky Way galaxy, no other galaxies will be visible.

Once the stars burn out, the dominant features of the universe will be black holes - until they too evaporate, leaving a universe barely above absolute zero, in a new 'dark era' which will last far longer than any which came before it.

But DESI scientists are actually optimistic that the new data (which is still being analyzed) will lead to a new understanding of physics.

The DESI team have already used their observations to detect a new Quasar (above), one of the brightest types of galaxies visible from Earth

The new results will likely mean a new understanding of dark energy — and, thus, even of the 'standard model' scientists have relied on to understand the physics that undergirds our universe.

'Essentially we have to start from scratch,' Physics professor Carlos Frenk of Durham University told The Guardian earlier this year. 

And other researchers believe this reckoning for dark energy is well over due.

'The idea that dark energy is varying is very natural,' according to Princeton University cosmologist Paul Steinhardt.

If it were not, as Steinhardt told Quanta: 'It would be the only form of energy we know which is absolutely constant in space and time.' 

WHAT IS DARK ENERGY?

Dark energy is a phrase used by physicists to describe a mysterious 'something' that is causing unusual things to happen in the universe. 

The universe is full of matter and the attractive force of gravity pulls all matter together. 

Then came 1998 and the Hubble Space Telescope observations of very distant supernovae that showed that, a long time ago, the universe was actually expanding more slowly than it is today.

The universe is not only expanding, but it is expanding faster and faster as time goes by,' Dr Kathy Romer, scientist at the Dark Energy Survey told MailOnline, as illustrated in this Nasa graphic

So the expansion of the universe has not been slowing due to gravity, as everyone thought, it has been accelerating. 

No one expected this, no one knew how to explain it. But something was causing it.

'The universe is not only expanding, but it is expanding faster and faster as time goes by,' Dr Kathy Romer, scientist at the Dark Energy Survey told MailOnline.

'What we'd expect is that the expansion would get slower and slower as time goes by, because it has been nearly 14 billion years since the Big Bang.'

{ https://www.dailymail.co.uk/ }

19-09-2024 om 23:23 geschreven door peter  

See the Northern Lights from SPACE: NASA astronaut on board the ISS films a stunning video of the astronomical light display

• Mr Dominick has been on board the ISS since March 3, 2024
• He has tweeted a stunning bird's-eye-view of the Northern Lights 

By Shivali Best For Mailonline

Witnessing the Northern Lights is something that features on many people's bucket-lists.

Now, one lucky astronaut has trumped seeing them from Earth, and instead has posted an incredible video of the aurora from space.

Matthew Dominick, a NASA astronaut currently on board the International Space Station (ISS), tweeted his bird's-eye view of the Northern Lights.  

The stunning footage has garnered huge attention, with fans dazzled by the unique view of the aurora. 

Even NASA itself was impressed, with the NASA Earth X account replying: 'These videos never get old.'

Mr Dominick launched to the ISS on March 3, 2024 as commander of NASA’s SpaceX Crew-8 mission. 

He’s serving as a flight engineer aboard the orbiting laboratory and was expected to spend around six months on the ISS, although his return to Earth could be pushed back amid the issues with the Boeing Starliner. 

While he spends most of his time on the ISS conducting scientific experiments, Mr Dominick also regularly snaps photos and films footage from his unique vantage point.  

'Timelapse of the moon setting into streams of red and green aurora followed by a sunrise lighting up Soyuz with a light blue,' he wrote in the caption with his latest video.

'The aurora have been amazing the past few days.'

His video has already been viewed almost 800,000 times, and several fans have replied, expressing their amazement. 

'Man that is just amazing... what a sight,' one user wrote. 

Another added: 'you are becoming the ultimate space photographer, great work again!'

While he spends most of his time on the ISS conducting scientific experiments, Mr Dominick also regularly snaps photos and films footage from his unique vantage point

His video has already been viewed almost 800,000 times, and several fans have replied, expressing their amazement

And one joked: 'What a strange world. Fun to visit, I'm sure.'

Auroras are caused by disturbances in Earth's 'magnetosphere' (its system of magnetic fields) due to powerful activity on the sun. 

High-energy particles travel from the sun towards us at hundreds of miles per second before bombarding our magnetosphere.

At this point, some of the energy and small particles can travel down the magnetic field lines at the north and south poles into our planet's atmosphere.

There, the particles interact with gases in our atmosphere, resulting in beautiful displays of light in the sky, known as auroras. 

Oxygen gives off green and red light, while nitrogen glows blue and purple. 

WHAT ARE AURORAS AND WHAT TRIGGERS THE STUNNING NATURAL DISPLAYS?

The Northern and Southern Lights are natural light spectacles triggered in our atmosphere that are also known as the 'Auroras'.

There are two types of Aurora - Aurora Borealis, which means 'dawn of the north', and Aurora Australis, 'dawn of the south.'

The displays light up when electrically charged particles from the sun enter the Earth’s atmosphere. 

There are two types of Aurora - Aurora Borealis (file photo), which means 'dawn of the north', and Aurora Australis, 'dawn of the south.' The displays light up when electrically charged particles from the sun enter the Earth’s atmosphere

Usually the particles, sometimes referred to as a solar storm, are deflected by Earth’s magnetic field.

But during stronger storms they enter the atmosphere and collide with gas particles, including hydrogen and helium.

These collisions emit light. Auroral displays appear in many colours although pale green and pink are common.

{ https://www.dailymail.co.uk/ }

19-09-2024 om 23:03 geschreven door peter  

Both asteroids were captured in a series of radar images obtained by the Deep Space Network’s Goldstone Solar System Radar near Barstow, California. The principal technique for studying asteroids is radar – called planetary radar. While astronomers can study the Universe by capturing light from stars, planets, and galaxies, they can also study nearby objects by shining radio light on them and analyzing the signals that echo back. Planetary radar can reveal incredibly detailed information about our planetary neighbors.

“When astronomers are studying light that is being made by a star, or galaxy, they’re trying to figure out its properties,” said Patrick Taylor, radar division head for the National Radio Astronomy Observatory, in an interview I did with him earlier this year. “But with radar, we already know what the properties of the signals are, and we leverage that to figure out the properties of whatever we bounced the signals off of. That allows us to characterize planetary bodies – like their shape, speed, and trajectory. That’s especially important for hazardous objects that might stray too close to Earth.”

2024 ON was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) on Mauna Loa in Hawaii on July 27. The asteroid was discovered by the Catalina Sky Survey in Tucson, Arizona, on May 4.

NASA labels objects larger than 492 feet that come within 4.6 million miles of Earth “potentially hazardous objects,” so scientists are monitoring 2024 JV33 for potential danger even though they don’t expect the asteroid to pose a threat in the future..

 { https://www.universetoday.com/ }

19-09-2024 om 22:31 geschreven door peter  

These four samples will then be sent to Earth for quality analysis and testing. Two will be sent to the ESA’s European Space Research and Technology Centre (ESTEC) in the Netherlands, a third to the Technical University of Denmark (DTU), and the fourth to the ESA’s European Astronaut Centre (EAC) in Cologne, where it will be integrated into the LUNA facility—a lunar analog environment designed for astronaut training. The availability of ISM will significantly reduce the challenges of resupplying spacecraft as they travel to the Moon, Mars, and other locations in deep space.

For long-duration missions on the lunar surface, the ability to print machine parts and ship them directly from LEO will reduce the number of launches needed to sustain operations there. As for Mars, the ability to manufacture replacement parts, repair equipment, and construct specific tools on demand will ensure a measure of autonomy for mission crews and reduce their reliance on resupply missions sent from Earth. This is especially important given the limited launch windows to Mars (every 26 months) and the time it takes to make a one-way transit (6 to 9 months).

NASA is also pursuing an ISM project aboard the ISS with the help of its commercial partners through the Marshall Space Flight Center (MSFC), with additional support provided by the physics-based modeling group at NASA’s Ames Research Center. These efforts began in 2014 when NASA launched the first 3D printer (manufactured by Made In Space, Inc.) to the ISS. This technology demonstrator used the fused filament fabrication (FFF) process to create objects out of plastic and proved that 3D printing could work in a microgravity environment.

This was followed by the creation of the Additive Manufacturing Facility (AMF), which can print using a variety of materials. These devices allowed for the creation of the first 3D-printed tools in space, including a plastic wrench, a rachet wrench, and more. In 2019, NASA added the ReFabricator experiment to the ISS, which was developed by Tethers Unlimited to create 3D-printed parts using recycled plastic materials. However, the ESA’s technology demonstrator is the first to successfully print a metal component in microgravity conditions.

The experiments will not stop there. In 2021, NASA sent another 3D printer to the ISS, the Redwire Regolith Print (RRP), designed to fashion construction materials out of lunar regolith. They are also investigating how Moon rover wheels can be 3D-printed on the lunar surface and how Martian rocks and minerals could be used to manufacture whatever future missions will need in situ. In collaboration with the University of Texas at El Paso (UTEP) and Youngstown State University (YSU), NASA is also considering how batteries could be 3D printed using lunar or Martian resources.

The potential applications for this technology are almost limitless and are integral to all plans for human expansion beyond Low Earth Orbit (LEO).

Further Reading: 

• ESA

NASA astronaut and Expedition 71 Flight Engineer Jeanette Epps configures the Metal 3D printer that manufactures experimental samples printed with stainless steel abaord the International Space Station's Columbus laboratory module. 

(Image credit: NASA/JSC)

NASA astronauts (from left) Suni Williams, Pilot for Boeing's Crew Flight Test, and Jeanette Epps, Expedition 71 Flight Engineer, configure the Metal 3D printer inside the Columbus laboratory module. They retrieved an experimental sample printed with stainless steel, replaced a substrate in the advanced manufacturing hardware, then reinstalled the 3D printer back in Columbus' European Drawer Rack-2. 

(Image credit: NASA/JSC)

 { https://www.universetoday.com/ }

19-09-2024 om 20:45 geschreven door peter  

We are all familiar with our one Moon but other planets have different numbers of moons; Mercury has none, Jupiter has 95 and Mars has two. A new paper proposes that Mars may actually have had a third larger moon. Why? The red planet has a triaxial shape which means it bulges just like Earth does but along a third axis. The paper suggests a massive moon could have distorted Mars into this shape. 

Celestial bodies that orbit planets or dwarf planets are known as moons. They vary significantly in size from just a few kilometres to several thousand kilometres. Earth’s Moon (notice capital ‘M’) is the moon everyone is familiar with but there are many fascinating moons in the outer Solar System from the largest moon Ganymede to the icy ocean world Europa or Titan with its methane lakes. Even Mars has two moons; Phobos and Deimos.

In a paper published by Michael Efroimsky from the US Naval Observatory in Washington the shape of Mars is explored with a view to assessing the liklihood of a third moon of Mars. Efroimsky explains that the triaxial nature of Mars is noticeable through the equatorial ellipticity which is produced by the Tharsis Rise. Another less noticeable bulge is located almost opposite to the Tharsis rise and is in the Syrtis Major Planum region.

The paper proposes the peculiar bulge shape of Mars has been caused by two different elements. The initial shape was caused by a massive moon in orbit around the young and pliable Mars. It was in a synchronous or captured orbit so the same face of Mars was always pointing toward the moon. Under the constant tug of gravity, a triaxial ellipsoid shape evolved. A triaxial ellipsoid is shaped like a rugby ball but the three axes are of different lengths. The longest axis was aligned to the Moon while the others were forged by other tidal effects. 

The second element of the development of the shape of Mars relates to the convection processes under its surface. After the triaxial ellipsoid shape developed, the tidally raised regions became more prone to uplift driven by convection, tectonic and volcanic activity. The activity slowly enhanced the triaxial ellipticity seen today. 

Efroimsky demonstrates that a moon of less than a third of the mass of the Moon, in a synchronous orbit around Mars was capable of creating the initial triaxiality (this is my new favourite word!) The research also put showed that the asymmetry of the equator was significant if the synchronous moon existed while Mars still have magma oceans, and was weaker if the moon showed up at the solidification stage.

In order for the second element to be evidenced, further research is required. However Efroimsky believes the tidal deformations could very easily oscillate and generate heat. A moon in an elliptical but synchronous orbit would appear to oscillate east/west around the same region of sky. This would enhance the tidal deformation and internal heating of the system giving credence to Efroimsky’s theory that Mars did indeed once have a third larger moon. 

Source : 

• A synchronous moon as a possible cause of Mars’ initial triaxiality

{ https://www.universetoday.com/ }

19-09-2024 om 20:25 geschreven door peter  

Story by Robert Lea

On Friday, 13, 2029, Earth will have a fascinating and intimidating visitor in the form of the "God of Destruction" asteroid Apophis. The asteroid — named after the Egyptian serpent god of chaos and destruction Apep — is so large and will pass within 19,000 miles (30,600 kilometers) of Earth, so close to our planet that it could be visible to the naked eye. 

Will Apophis Hit Earth in 2036?

New research has suggested that if other much smaller space rocks hit Apophis, the asteroid, which is almost as wide as the Empire State Building is tall, could be redirected, and Earth might not be narrowly missed by it during subsequent passages or in extreme circumstances, even during the 2029 passage. But don't panic just yet. 

Research author Paul Wiegert, an astronomer at the University of Western Ontario, told Space.com that the odds of a dangerous asteroid strike on Apophis are very low. "The odds are essentially 1 in a million that an asteroid strike could deflect Apophis enough to put it in danger of a future post-2029 collision, and only 1 in a billion that it could send Apophis colliding with Earth in 2029," he said.

"I calculated the odds of asteroid Apophis, whose current path is computed to take it near but safely past our planet in 2029, being deflected onto a more dangerous path by an unexpected small asteroid impact," Wiegert explained. "These are the same kind of small asteroids that occasionally appear in our atmosphere as 'shooting stars' or 'fireballs' and could strike Apophis just as unexpectedly."

Related:

•  'God of Destruction' asteroid Apophis will come to Earth in 2029 — and it could meet some tiny spacecraft

Wiegert explained that in the research, he questioned whether an asteroid would strike during the period from 2021 to 2027 when our telescopes couldn't observe Apophis and if this could deflect it enough to make it dangerous. 

"Asteroid Apophis is essentially unobservable from now until 2027 because it is in the daytime sky, and so it could be hit without us being immediately aware of the event," he continued.

A chaotic event could mean the rise of Apophis

Discovered in 2004, Apophis (full designation Apophis 99942) immediately rose to the top of tables that measure the risk of so-called potentially hazardous asteroids (PHAs) asteroids with widths of 460 feet (140 meters) or more that come within 20 lunar distances of Earth. 

Both the size of Apophis and its trajectory saw it remain at the top of both the European Space Agency's (ESA's) "impact risk list" of PHAs and NASA's Sentry Risk Table for almost two decades.

That was until a close flyby of the asteroid in March 2021 allowed NASA scientists to determine Apophis actually won't hit the Earth for at least 100 years. 

Now, this new research shows that chance encounters with other space rocks could redirect the 1,000-foot-wide (305-meter-wide)  Apophis to put it on a collision course with Earth in 2029 or later, meaning it could rocket back to the top of the risk tables. 

Wiegart calculated the effect that objects of different sizes would have if they struck Apophis and then used the number of objects of these sizes that strike Earth each year to determine the probability of such an impact.

"An asteroid about 60 centimeters (24 inches) across could, if it struck Apophis from exactly the right direction, put Apophis onto a post-2029 collision course. But it would take a 3 meter (10 foot) diameter asteroid to strike Apophis, again, in just the right direction, to put in danger of a collision in 2029," Wiegart said. "These kinds of collisions are extremely rare."

When considering the angle necessary to divert Apophis so that it could strike Earth on a future passage, Wiegart found the chance of the asteroid being diverted to hit our planet after 2029 to be 1 in 1 million. The chances of a roughly 3-meter-wide asteroid hitting Apophis and putting it on a collision course with Earth in 2029 were  1 in 2 billion.

An illustration of NASA's Double Asteroid Redirection Test, or DART, as it approaches its target. Could such measures be deployed against Apophis??

(Image credit: NASA/Johns Hopkins APL)© Provided by Space

These low odds are fortunate considering the huge damage Apophis would cause were it to strike Earth. The Planetary Society estimated that if Apophis were to hit Earth it could release energy equal to more than 1,000 megatons of TNT, equivalent to the detonation of tens or even hundreds of nuclear weapons.

This could spread devastation across a radius of hundreds of miles. Even though it won't come close to the devastation caused 65,000,000 years ago by the asteroid that wiped out the dinosaurs and two-thirds of all species on Earth, millions of people would die if Apophis hit a highly populated metropolitan area.

If we discover Apophis is on a collision course with Earth during its next passages in 2029, 2036, and 2068, we would have some options to attempt to divert it. For instance, just as a small impact could shift the God of Destruction space rock toward Earth, another small collision could reorientate its trajectory away again if space agencies had enough warning.

In 2022, NASA tried out this idea, striking the asteroid system Dimorphos and Didymos with the Double Asteroid Redirection Test (DART) impactor and measuring the change in its motion.

"It is possible that a mission like DART could be used to divert Apophis back onto a safe path, but exactly how and if this would work has yet to be worked out," Wiegart said. 

Other diversions range from the forceful, such as hitting an asteroid with a nuclear weapon, to the sublime, such as painting one side of an asteroid black, causing it to absorb more solar radiation, shifting its center of mass, and altering its trajectory. These methods are well-founded scientifically but are yet to be tested.

"It's difficult to say what other diversion methods would work, but scientists are thinking hard about our options," Wiegart said.

Though Apophis is unlikely to live up to its fearsome name in 2029 by impacting Earth, its scientific impact will be immeasurable. Plans are already being hatched to use spacecraft and satellites to rendezvous with the asteroid as it heads toward its closest approach to our planet.

"Apophis' upcoming close pass in 2029 is a natural milestone for our planet, as we move into a time where we as a global community have the ability to avoid disastrous asteroid impacts like those that may have extinguished the dinosaurs," Wiegart concluded. "The astronomical community as a whole is continuing to think about dangerous asteroids like Apophis as well as possible next steps."

• Wiegart's Apophis research was published in The Planetary Science Journal.

Watch it here:

Animation of Asteroid Apophis’ 2029 Close Approach with Earth

Apophis, The Asteroid That Could Hit Earth In 2029

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19-09-2024 om 01:13 geschreven door peter  

• https://youtu.be/XYu9YC_rGII

Engineers at NASA have successfully fired up a set of thrusters Voyager 1 hasn’t used in decades to solve an issue that could keep the 47-year-old spacecraft from communicating with Earth from billions of miles away.

When Voyager 1 lifted off to space on September 5, 1977, no one expected that the probe would still be operating today.

As a result of its exceptionally long-lived mission, Voyager 1 experiences issues as its parts age in the frigid outer reaches beyond our solar system. When an issue crops up, engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, have to get creative while still being careful of how the spacecraft will react to any changes.

Currently the farthest spacecraft from Earth, Voyager 1 is about 15 billion miles (24 billion kilometers) away. The probe operates beyond the heliosphere — the sun’s bubble of magnetic fields and particles that extends well beyond Pluto’s orbit — where its instruments directly sample interstellar space.

Earlier this year, engineers spotted an issue when the fuel tube inside one of Voyager’s thrusters became clogged. If the thrusters are clogged, they can’t generate as much force to keep the spacecraft steady. Voyager’s thrusters keep the spacecraft oriented in a way that it can communicate with Earth.

If Voyager 1 isn’t positioned in such a way so that its antenna is pointed at Earth, the spacecraft can’t “hear” commands from mission control or send back data, according to Calla Cofield, media relations specialist at JPL.

“If the thrusters that keep the antenna pointed at Earth get clogged, that would be end of mission,” she said.

The team realized it would have to send commands to the spacecraft to switch to another set of thrusters, but the fix wouldn’t be a simple one.

A recurring problem

It’s not the first time Voyager 1 has needed to switch over to another set of thrusters in recent decades. Fortunately, the spacecraft has three sets of thrusters: two sets of attitude propulsion thrusters and one set devoted to trajectory correction maneuvers.

Voyager 1 used the thrusters for a variety of purposes as it flew by planets such as Jupiter and Saturn in 1979 and 1980, respectively.

Now, the spacecraft is traveling on an unchanging path away from our solar system, so it just requires one set of thrusters to help keep its antenna pointed at Earth. To fuel the thrusters, liquid hydrazine is converted into gas and released in about 40 short puffs per day to keep Voyager 1 oriented correctly.

Over time, engineers discovered that a fuel tube inside the thrusters can become clogged with silicon dioxide, a byproduct of the fuel tank’s rubber diaphragm aging. As the thrusters become clogged, they generate less force.

In 2002, the team commanded Voyager 1 to switch to its second set of attitude propulsion thrusters when the first set showed signs of clogging. Engineers switched again to the trajectory correction thruster set in 2018 when the second set also appeared clogged.

But when the team recently checked on the status of Voyager’s trajectory correction thrusters, they were even more clogged than the previous two sets of thrusters.

When the team initially switched Voyager over to the trajectory correction thrusters six years ago, the tube opening was 0.01 inches (0.25 millimeters) across. But now, clogging has reduced it to 0.0015 inches (0.035 millimeters) — half the width of a human hair, according to NASA.

It was time to rotate back to another set of attitude propulsion thrusters.

Making a challenging swap

As Voyager 1 and its twin probe, Voyager 2, have aged, the mission team has slowly turned off nonessential systems on both spacecraft to conserve power, including heaters. As a result, components on Voyager 1 are colder now, and the team knew it couldn’t just send a command to Voyager 1 to switch immediately to one of the attitude propulsion thrusters without doing something to warm them up.

But Voyager 1 doesn’t have enough power to switch any heaters back on without turning something else off, and its scientific instruments are too valuable to shut off in case they don’t come back on, the team said.

After going back to the drawing board, the team realized it could shut off one of the spacecraft’s main heaters for about an hour, which would enable engineers to turn on the thruster heaters and safely make the switch.

This plan worked, and by August 27, Voyager 1 was back to relying on one of its original thruster sets to stay in touch with Earth.

The team has taken steps to use the thrusters less, and it is expecting to get another two to three years out of the original set, said Todd Barber, Voyager propulsion engineer.

Once the spacecraft has exhausted this thruster set, Voyager 1’s remaining option is the other already clogged set of attitude propulsion thrusters.

“All the decisions we will have to make going forward are going to require a lot more analysis and caution than they once did,” said Suzanne Dodd, Voyager’s project manager, in a statement.

Voyager 2 has also gone through thruster swaps in 1999 and 2019, and “the situation there is less dire,” Barber said. Voyager 2 has traveled more than 12 billion miles (20 billion kilometers) from Earth.

The information collected by these long-lived probes is helping scientists learn about the cometlike shape of the heliosphere and how it protects Earth from energized particles and radiation in interstellar space.

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19-09-2024 om 00:20 geschreven door peter  

Massive underground ocean found 700 km below Earth’s surface : Groundbreaking discovery stuns scientists

Scientists have made a groundbreaking discovery that challenges our understanding of Earth's water cycle. A massive underground ocean, three times larger than all surface oceans combined, has been found 700 kilometers beneath the Earth's surface. This astonishing find could revolutionize theories about the origin of water on our planet and its long-term stability.

Unveiling the hidden reservoir

The monumental reservoir lies hidden within a blue rock formation known as ringwoodite, deep within Earth's mantle. This layer of scorching rocks, situated between the planet's surface and core, harbors an aqueous secret of immense proportions. The discovery lends credence to the theory that oceans may have gradually seeped from Earth's interior, rather than originating from cometary impacts.

Steven Jacobsen, lead researcher from Northwestern University in Illinois, states, "This is tangible evidence that water on Earth came from within." The implications of this finding are far-reaching, potentially explaining the consistent size of surface oceans over millions of years.

The underwater expanse is not a traditional ocean but rather water molecules trapped within the crystal structure of ringwoodite. This unique arrangement allows for an enormous amount of water to be stored in a relatively compact space.

Innovative research techniques

To uncover this subterranean ocean, scientists employed cutting-edge seismological methods. The research team utilized an extensive network of 2,000 seismographs across the United States to study seismic waves generated by over 500 earthquakes. These waves, capable of penetrating deep into the Earth's core, can be detected at the surface, providing valuable data about the planet's internal structure.

By measuring the velocity of these waves at various depths, researchers were able to determine the composition of the rocks they traversed. The presence of water was detected when the waves slowed significantly upon entering the water-rich rock layer. Jacobsen describes it as "a layer of rocks with water along the edges between the grains, as if they were sweating."

This innovative approach to studying Earth's interior has opened new avenues for understanding our planet's composition and evolution. The team's methodology can be summarized as follows :

• Deployment of seismographs across a wide area
• Collection of data from numerous earthquakes
• Analysis of seismic wave velocities at different depths
• Interpretation of rock composition based on wave behavior

Implications for Earth's water cycle

The discovery of this colossal subterranean reservoir has profound implications for our understanding of Earth's water cycle. Scientists now believe that this hidden ocean may play a crucial role in maintaining the stability of surface water bodies. "We should rejoice at the presence of this reservoir," Jacobsen remarks. "If it weren't there, it would be on the Earth's surface, and mountain tops would be the only visible land."

This finding challenges previous theories about the origin of Earth's water, which often attributed it to cometary impacts during the planet's early history. The new evidence suggests a more complex interplay between the planet's interior and surface, with water potentially cycling between these realms over geological timescales.

To better understand the global implications of this discovery, researchers plan to gather additional seismic data from around the world. Their goal is to determine whether mantle melting is a common phenomenon or unique to certain regions. The results could provide invaluable insights into Earth's water cycle and its long-term stability.

As scientists continue to probe the depths of our planet, more revelations about Earth's complex systems are likely to emerge. The discovery of this enormous underground ocean not only reshapes our understanding of the planet's water cycle but also opens up new questions about the potential for life in extreme environments and the long-term sustainability of Earth's ecosystems.

• https://youtu.be/aPBVGXdsR0I

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18-09-2024 om 23:59 geschreven door peter  

Enter EVE, which consists of three main components. The transport rails allow the robot to move to the correct location in the greenhouse. Its robotic “arm” enables the robot to position itself effectively to complete its assigned task, and the end effector can push, pull, pick up, or perform other manual tasks. The system uses about 700W and weighs about 170 kg fully installed.

First, let’s look at the transport trails. It’s actually an off-the-shelf commercial system for use in industrial automation. The eXtended Transport System, made by Beckhoff, an industrial automation company, can be mounted in different configurations. It allows whatever is attached to it to be driven to various locations based on a series of signals that control the “mover” to which the robotic arm would be connected.

The robotic arm is based on DLR’s “This Is Not an Arm” (TINA) project. It has seven degrees of freedom, which allows for precise positioning of its end effector. Each of its three joints has around three electronic controllers for motor control, power management, and communication. It’s supported by a camera system that senses its surroundings and allows remote operators to tell where the end effector is positioned.

The Compliant Low-Cost Antagonistic Servo Hand (CLASH) is the end effector. It has two “fingers” and a “thumb” to grip soft objects using force feedback sensors in its fingertips. It can also sense pressure from other components, such as the hand’s “tendons” and thumb and figure position.

These positioning and end-effector systems can work effectively together to perform the greenhouse’s daily maintenance tasks. For now, at least, it will require a skilled operator to do so, but that operator doesn’t have to be co-located with the greenhouse on the Moon – it could be back on Earth or even on the Lunar Gateway station orbiting above the lunar surface. Continuous operation is essential, though, as the first stages of the permanent occupation of the Moon involve temporary stays, where there will be long stretches with no human inhabitants.

DLR is fully backing the development of the EDEN LUNA greenhouse and the EVE robotic arm. Later this year, EVE will be fully integrated into the greenhouse at the Institute of Space Systems in Bremen, followed by a specially designed facility for the greater LUNA project of ESA/DLR in Cologne. As of now, both EVE and EDEN LUNA seem on track to be put through their paces before officially supporting the continual human occupation of the Moon within the next decade.

Learn More:

• Prince et al. – EDEN Versatile End-effector (EVE): An Autonomous Robotic System to Support Food Production on the Moon
• UT – Plants Could Grow in Lunar Regolith Using Bacteria
• UT – A Greenhouse on the Moon by 2014?
• UT – Practical Ideas for Farming on the Moon and Mars

Lead Image:

• Greenhouse concept art on the Moon.
  Credit – DLR

{ https://www.universetoday.com/ }

18-09-2024 om 23:17 geschreven door peter  

Mars has always held a special place in our hearts, likely from hints over the decades of perhaps finding signs of life, albeit fossilised and primitive. It’s been the subject of study from telescopes and space missions alike, most notably ESA’s Mars Express which has been observing the red planet for 20 years. Over the two decades of observation it has studied an amazing variety of atmospheric phenomenon which have now been catalogued in a new ‘Cloud Atlas.’ Many will be familiar to sky watchers on Earth but some are very different. 

The atmosphere of the red planet is thin and mostly composed of carbon dioxide. There are traces of nitrogen and argon but with an atmospheric pressure of just 1% of the Earth’s it’s inhospitable for human life. The rarefied atmosphere provides insufficient insulation to the surface leading to aggressive temperature fluctuations from -125°C on night time side to 20°C during the day. It’s not unusual for dust storms to whip up in the atmosphere sometimes encircling the entire planet. It’s in this atmosphere that a multitude of cloud features have been observed. 

Over the last 20 years, Mars Express has been studying the cloud formations in the Martian atmosphere. It was launched in June 2003 to study Mars remotely from an orbit around the red planet. Mars Express was not only studying atmospheric phenomenon but also the surface, subsurface and geological history. With a suite of scientific instruments from high resolution cameras and radar to spectrometers and atmospheric sensors, Mars Express is well equipped for the task. 

Arsia Mons Elongated Cloud (AMEC): This elongated cloud has formed as a result of wind encountering the Arsia Mons mountains. It forms almost every day during a specific season, from early morning until noon. 

(Image credit: ESA/DLR/FU Berlin/A. Cowart)

Using the High Resolution Stereo Camera (HSRC) on board Mars Express, images of a multitude of clouds have been captured. The clouds are usually the result of microscopic dust particles in the atmosphere around which, water and carbon dioxide crystals form. The dust particles themselves can be left hanging in the atmosphere following unusually strong winds that lift large quantities of dust into the atmosphere. They are occasionally seen as large beige coloured clouds. In the north polar regions it’s possible to see giant spiral dust storms as cyclonic storm systems develop. They are one of the drivers of the global weather systems seen on Mars and studying them is crucial to understanding the dynamics of the atmosphere. 

So called ‘gravity waves’ are a common sight on Mars as they are on Earth. Somewhat resembling rolling hills or the rippling of water, they are usually seen in the mid-latitudes in the colder winter months. A particular type of these gravity waves, known as Lee waves, can build up on the downwind side of mountains and ridges. The presence of the mountain or other large obstacle disturbs the laminar flow of air to generate the effect.

Seemingly parallel white lines are Martian clouds sculpted by gravity waves, while the splotches of brown are wind-lifted dust clouds left wafting in the air due to seasonally sharp differences in temperatures and pressures. 

(Image credit: ESA/DLR/FU Berlin)

An example of cloud streets over Vastitas Borealis, a large area near the North Pole mostly devoid of craters

(Image credit: ESA/DLR/FU Berlin/A. Cowart)

Lee waves are a special type of cloud created by the wind encountering obstacles and build up on the ‘leeward‘ or downwind side. The geometries of the lee waves depend on the shape of the obstacles.

(Image credit: ESA/DLR/FU Berlin)

The study has led to a Martian cloud spotters dream, the publication of a fully browsable 20-years of cloud images and data. It was created by the German Aerospace Centre (DLR) in Berlin and is proving invaluable helping researchers to gain a better understanding of the Martian atmosphere. In particular how the different dynamical processes can lead to the clouds seen. The ‘Atlas’ which is available to the public here has been presented at the Europlanet Science Congress in Berlin by Daniela Tirsch form DLR.

Source : 

• Cloud Atlas of Mars Showcases Array of Atmospheric Phenomena

{ https://www.universetoday.com/ }

18-09-2024 om 23:07 geschreven door peter  

Scientists discover a 'smiley face' on Mars - and it could contain signs of life

• READ MORE: NASA discovers first 'possible' signs of life on Mars 

By Ellyn Lapointe For Dailymail.Com

Astronomers have discovered a smiley-face-shaped structure on Mars - and it could be more than just a planetary quirk. 

Researchers believe that it may be harboring signs of past life on the Red Planet. 

This grinning formation is made up of a pair of crater eyes and rings of ancient salt deposits.

These deposits are the remains of an ancient body of water that dried up long ago, leaving behind this emoji-like remnant that is only visible when viewed with an infrared camera.

The European Space Agency (ESA) - which snapped the photo - said: 'These deposits, remnants of ancient water bodies, could indicate habitable zones from billions of years ago.'

The European Space Agency snapped this photo of a smiley-face-shaped salt deposit on Mars that could harbor evidence of ancient alien life on the Red Planet

Scientists aren't sure exactly how big the smiley-face is, but it's one of 965 other salt deposits that have recently been catalogued on Mars' surface, which range in size from 1,000 to 10,000 feet wide.

Salt deposits are accumulations of salt - or chloride - found on a planetary surface. On Mars, they are the remnants of ancient bodies of water that dried up when the planet underwent a major climatic shift eons ago. 

Read More

Bezos' Boeing moment: NASA delays upcoming Mars mission due to issues with Blue Origin rockets 

Before the last puddles of Mars' liquid water disappeared, they may have been a 'haven' for microbial life, according to the ESA. 

These puddles would have been extremely salty, and thus the remains of microbes that once lived in them may still be preserved to this day - hiding in deposits like this smiley face. 

The ESA captured this image using their ExoMars Trace Gas Orbiter, which has been measuring the levels of methane and other gases in Mars' atmosphere since 2016 to help scientists understand possible biological or geological activity on the Red Planet.

Normally, salt deposits on Mars' surface are invisible. 

But the orbiter's infrared cameras allow us to see them glowing pink or violet - revealing the smiley-face.

The photo was published as part of a study in the journal Scientific Data. 

These salt deposits are typically invisible, but the infrared cameras on the ESA's ExoMars Trace Gas Orbiter allow us to see them glowing pink or violet

As Mars' liquid water disappeared, the last salty puddles could have harbored surviving microbial life, and their remains could be preserved in the resulting salt deposits

The research team, led by scientists from the University of Bern in Sweden, used images taken by the orbiter to create the most robust catalog of Mars' chloride salt deposits to-date. 

The new catalog contains data for nearly 1,000 different deposits located all across the planet's surface. 

These deposits paint a picture of ancient Mars that is very different than the red desert planet we know today. Billions of years ago, Mars hosted bodies of liquid water.

'In the distant past, water formed magnificent landforms such as riverbeds, channels, and deltas on the Red Planet,' said planetary scientist and study lead author Valentin Bickel in an ESA statement. 

But studies suggest that sometime between three billion and two billion years ago, severe climate change caused these bodies of water to dry up. 

That extreme climatic shift was likely triggered by the loss of Mars' magnetic field, which allowed solar wind to erode the atmosphere and caused liquid water to freeze, evaporate or become trapped within the planet's surface.

Now, salt deposits are some of the only evidence we have of Mars' ancient water bodies. 

What's more, studying them could reveal clues about ancient microbial life that once lived in the planet's liquid water, according to the study.

'The new data has important implications for our understanding of the distribution of water on early Mars, as well as its past climate and habitability,' Bickel said. 

While there is no conclusive evidence pointing to past or present life on Mars, this study adds to a growing body of research that has reignited the search for microbes on the Red Planet.

European Space Agency Shares Pic Of 'Smiley Face' Spotted On Mars

See the post here:

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18-09-2024 om 00:40 geschreven door peter  

New map of Mars reveals hidden 'structures' below the Martian surface

• READ MORE:  Scientists discover smiley-face on Mars that may hold signs of life

By Ellyn Lapointe For Dailymail.Com

A new map of Mars has revealed mysterious structures hiding beneath the sediment layers of a lost ocean.

The researchers detected about 20 features scattered around the planet's north polar cap that are significantly denser than their surroundings. 

The structures vary in shape and size, with one resembling the shape of a dog, leaving the team puzzled because they do not know exactly what the formations are or where they came from. But they do have some theories.

One idea is that the structures were compacted by ancient meteor strikes, or  formed by volcanic activity, but more research is needed to get to the bottom of these underground anomalies. 

A new analysis of Mars' gravitational field has revealed mysterious structures lurking beneath the planet's surface

The team of researchers from Denmark's TU Delft and Utrecht University presented their findings at the Europlanetary Science Conference in Berlin this week.

The team used tiny deviations in satellite orbits to create a picture of Mars' gravitational field, or the region of space around a planet where its gravitational force can be felt. 

Read More

• Bezos' Boeing moment: NASA delays upcoming Mars mission due to issues with Blue Origin rockets 

They did this to look for clues about how mass is distributed throughout the planet's subsurface. 

The team then combined these observations with data on the thickness and flexibility of the Mars' crust, as well as the dynamics of the planet's mantle and deep interior. 

These observations were collected by NASA's InSIGHT lander, which completed its study of Mars' crust, mantle and core in 2022.

This allowed the researchers to create a global density map of Mars that revealed the existence of 20 previously unknown underground structures scattered around the planet's north polar cap.

The structures are about 19 to 25 pounds per cubic foot denser than their surroundings, and vary in shape and size. 

Additionally, they are covered by a thick, smooth layer of sediment that may have once been a seabed. 

The researchers used tiny deviations in satellite orbits and data from NASA's InSIGHT lander to create a global density map of Mars

Their analysis revealed 20 previously unknown underground structures scattered around the planet's north polar cap

Billions of years ago, Mars was not the desert planet we know today. It was once covered in oceans and rivers, but water dried up in an extreme climactic shift. 

Now, the only evidence of these bodies of water lies in Mars' geologic record - like this sediment layer. 

As for the structures that lie beneath, 'there seems to be no trace of them at the surface,' lead author Bart Root, an assistant professor at TU Delft, said. 

'However, through gravity data, we have a tantalizing glimpse into the older history of the northern hemisphere of Mars.' 

This isn't the first time that scientists have uncovered oddities beneath the surface of Mars. 

In December 2023, China's Zhurong found large honeycomb-shaped crevasses buried dozens of meters beneath Mars' equator that likely formed when drastic temperature dips contract and fracture the ground.

But Root and his team are having a harder time figuring out what these most recently structures are, and where they came from. Right now, they have two main theories. 

Either the structures were compacted by ancient impact events, like meteor strikes, or they were formed by some kind of volcanic activity. This latter idea challenges scientists' longstanding view of Mars as a geologically inactive planet. 

But while studies have shown that Mars does not have as much geological activity as Earth, a growing body of evidence suggests that it isn't completely 'dead.'

Root's study adds to this evidence not just by discovering structures that may be volcanically formed, but through a totally separate finding. 

In addition to finding the mysterious structures, the team's analysis revealed that Mars' mantle may still host active geological processes that could be feeding Olympus Mons, the largest known volcano in the solar system.

Olympus Mons is located in the Tharsis Montes region near Mars' equator. Scientists estimate that it hasn't erupted for 25 million years.

The subterranean geology of the Tharsis region is incredibly dense, but Root and his team detected a much lighter mass lying 700 miles beneath the surface. 

He believes this mass is an enormous plume of magma that stretches 1,000 miles across in Mars' mantle. What's more, this plume might be in the process of bubbling to the surface.

'This means we need to rethink how we understand the support for the Olympus Mons volcano and its surroundings,' Root said. 

'It shows that Mars might still have active movements happening inside it, affecting and possibly making new volcanic features on the surface.' 

Intro to Areography | The Geography of Mars

A close-up photo taken by the Curiosity rover shows pure yellow sulfur crystals within a rock.

NASA/JPL-Caltech/MSSS

NASA’s Curiosity rover captured a close-up image of a rock nicknamed “Snow Lake." Nine days earlier, the rover had crushed a similar-looking rock and revealed sulfur crystals.

NASA/JPL-Caltech/MSSS

The Gediz Vallis channel is visible above the rocky area in the foreground.

NASA/JPL-Caltech

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18-09-2024 om 00:23 geschreven door peter  

Huge landslide unleashes 650-foot 'mega-tsunami' and causes Earth to vibrate for 9 DAYS 

• READ MORE: California rocked by swarm of five earthquakes in just 48 hours

By Ellyn Lapointe For Dailymail.Com

After a mountaintop collapsed into the sea in Greenland, a 'mega-tsunami' as tall as a skyscraper shook the Earth for nine straight days, baffling scientists around the world.

No one was injured by the landslide or resulting tsunami, but the 650-foot-tall wave destroyed roughly $200,000 worth of infrastructure at an unoccupied research station on Ella Island. 

What's more, the events occurred near a route that is commonly traveled by cruise ships. Had one been sailing through at this time, it could have led to tragedy. 

Until now, no one knew what caused the mysterious seismic activity that began in September 2023 and lasted over a week. It took an international team of scientists to trace it back to the landslide.

'When we set out on this scientific adventure, everybody was puzzled and no one had the faintest idea what caused this signal,' said Kristian Svennevig, study lead author and geologist at the Geological Survey of Denmark and Greenland.

Before and after the massive landslide that dumped 33 million cubic yards of ice and rock into a Greenland fjord, triggering a 650-foot-tall 'mega-tsunami' that shook Earth for nine days

Svennevig and her colleagues now believe that climate change set the stage for this landslide by melting a glacier at the base of the mountain and destabilizing enough ice and rock to fill 10,000 Olympic swimming pools. 

And as rising global temperatures continue to melt Earth's polar regions, destructive landslides like this one could become more common. 

The research team published their findings today in the journal Science. 

When seismic monitoring networks first detected the activity, scientists were perplexed for two reasons. 

First, the signal was much more spread out than the typical tight squiggles that an earthquake produces on a seismograph - a device used to record ground shaking.

'It oscillated with a 92-second-interval between its peaks, too slow for humans to perceive,' according to a statement from the University of California San Diego, one of the institutions that contributed to the research.

Second, the signal remained strong for nine straight days. Typical seismic events decay much more rapidly - the average earthquake lasts only seconds to minutes.

Scientists around the world quickly began working to get to the bottom of this strange signal. 

Climate change set the stage for this landslide by melting a glacier at the base of the mountain and destabilizing enough ice and rock to fill 10,000 Olympic swimming pools

The mega-tsunami destroyed roughly $200,000 worth of infrastructure at an unoccupied research station on Ella Island, but no one was hurt

Discussions online eventually turned up reports of a massive landslide that occurred on a mountain overlooking a remote fjord in East Greenland on September 16 2023.

To determine whether the landslide was connected to the mysterious shaking, a team of researchers led by Svennevig digitally reconstructed the landslide and resulting shakes.

They did this using a combination of seismic recordings from around the world, field measurements, satellite imagery and computer simulations.

The researchers also used supercomputers to simulate the 650-foot-tall mega-tsunami triggered by the 33 million cubic yards of rock and ice that crashed into the fjord. 

The waves sloshed back and forth inside the fjord in a phenomenon known as seiche. The researchers concluded that this sloshing is what caused the nine-day stretch of seismic activity that rocked the Earth last year. 

'Ultimately, it took a plethora of geophysical observations and numerical modeling from researchers across many countries to put the puzzle together and get a complete picture of what had occurred,' said co-author Robert Anthony, a geophysicist with the United States Geological Survey's Earthquake Hazards program, in a statement.

The findings demonstrate the 'complex, cascading hazards' driven by the impact of climate change on Earth's polar regions, according to the researchers.

'Climate change is shifting what is typical on Earth, and it can set unusual events into motion,' said co-author Alice Gabriel, a seismologist at the University of California San Diego, in a statement. 

Fortunately, no people were in the area when the enormous landslide and resulting tsunami occurred. But this incident emphasizes the importance of monitoring polar regions as climate change accelerates. 

{ https://www.dailymail.co.uk/ }

17-09-2024 om 23:54 geschreven door peter  

The Moon has inspired poets and artists, musicians and playwrights. The sight of our one and only Moon is familiar to anyone that has ever glanced up at the night time (and sometimes day time sky!) Every so often though, our Moon (note the use of capital ‘M’)is joined by a small asteroid that wanders too close. Astronomers have detected an 11-metre wide asteroid that has the snappy name 2024 PT5 and it came within 567,000 kilometres of Earth and will become a temporary satellite from 29 September until 25 November when it will leave our system. 

Planets, comets, satellites and asteroids are the main constituents of our Solar System, plus of course, the Sun. The asteroids are small rocky objects that orbit the Sun with the majority in orbits between Mars and Jupiter. These remnants of the early Solar System come in a wide range of sizes from those measuring just a few centimetres to others measuring hundreds of kilometres. They have no atmosphere and are usually irregular in shape. 

Asteroids that pass within 1.3 astronomical units (one astronomical unit is the average distance between the Sun and Earth) are typically referred to as near-earth objects (NEOs.) Their proximity to Earth means they may – if not immediately – pose a potential impact threat to Earth. Most NEO’s pass by harmlessly on each orbit but they are tracked for future threats. The study of this family of asteroids helps us to understand about the formation of the Solar System. 

On occasions, Earth can capture asteroids from the NEO group and for a short period, pull them into an orbit. These temporary captures can be very short lived not even lasting for an entire orbit before returning to their regular trajectory.  Others like 2006RH120 remained in orbit around Earth for a year, while some have been captured for more than a year. These mini-moon events have even turned out to be pieces of space junk like one identified in 2020 which turned out to be a rocket booster from the launch of Surveyor 2 in 1966!

Asteroid 2024 PT5 is a NEO that was discovered on 7 August 2024 by ATLAS, the Asteroid Terrestrial-impact Last Alert System. It measures 11 metres across and can approach within 1 million kilometres of Earth in an orbit whose path resembles a horseshoe shape. This complex type of orbit occurs when a smaller object orbits a relatively larger object. In the case of 2024 PT5, the gravitational attraction of Earth changes the shape of the asteroids elliptical orbit. The horseshoe shape is only evident when the orbit of the asteroid is mapped relative to both the Sun and the Earth.

The dynamics of the two objects means that for a period of 56 days from 29 September to 25 November, 2024 PT5 will officially orbit the Earth although it is only classed as a ‘temporary captured flyby.’ It will only perform one single orbit however before it returns to its usual heliocentric, Sun centred orbit. This won’t be the only time though as it is predicted to return again in 2055. 

Don’t get too excited about seeing it though. The object will be far too faint to be seen with the naked eye, even beyond the visual range of amateur telescopes. It is however possible for experienced amateur astronomers to capture images of the asteroid using astronomical imaging techniques.

Source : 

• A Two-month Mini-moon: 2024 PT5 Captured by Earth from September to November

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17-09-2024 om 22:01 geschreven door peter  

A skyscraper-sized asteroid is set to narrowly miss Earth next week, Nasa has warned.

The space rock, dubbed 2024 ON, has been classified as "potentially hazardous" - and is set to hurtle past our planet at a staggering speed of 19,685 miles per hour - approximately 25 times the speed of sound.

With a 220-480m diameter, 2024 ON dwarfs landmarks like the Shard or Eiffel Tower - and would sit at 14th in a list of the world's tallest skyscrapers.

But despite its size and speed, Nasa has maintained that 2024 ON is not expected to pose a danger to Earth or its inhabitants.

An asteroid is deemed "potentially hazardous" if it comes within 0.05 astronomical units (4.65 million miles) of Earth and exceeds 140m in diameter.

Fortunately, this space rock's closest approach to Earth will see it stay twice as far away as the moon - but 2024 ON is still classified as a near-Earth object (NEO) and is being monitored by Nasa.

Related video:

• The Most Dangerous Asteroid Is Here, But NASA Has a Plan (Bright Side)

The space agency's definition reads: "NEOs are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighbourhood."

It goes on to detail that comets are formed in the cold outer planetary system, whilst rockier asteroids originated in the warmer inner solar system between Mars and Jupiter.

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Asteroid warning issued by Nasa as meteor travelling at 19,000 miles an hour to narrowly miss Earth© GB News

(CA)

At its maximum estimated size, 2024 ON is still dwarfed by the largest known asteroid, Ceres, which boasts a diameter of 580 miles.

And despite its impressive dimensions, the approaching space rock will be too small to observe with the naked eye or even an average telescope.

Asteroids, remnants of ancient solar system collisions, travel at high speeds due to intense gravitational forces in space, and orbit the sun in elongated paths whilst rotating erratically.

Nasa's online tracker lists 2024 ON as one of the upcoming close approaches and highlights the agency's vigilance in monitoring potential threats from space.

The scientific interest in these celestial bodies stems from their status as relatively unchanged remnants of the solar system's formation process, dating back some 4.6 billion years.

Whilst 2024 ON's approach may seem alarming, it's important to note that such events aren't uncommon.

Nasa continuously tracks and studies these objects to better understand our cosmic neighbourhood and assess any potential risks to our planet.

The agency's efforts in asteroid detection and monitoring play a crucial role in planetary defence strategies, ensuring Earth's safety from potential space-borne hazards.

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17-09-2024 om 18:10 geschreven door peter  

On Thursday, Mr. Isaacman and Ms. Gillis became the first private astronauts to successfully complete a spacewalk. The operation involved the crew letting all the air out of the spacecraft, because it had no airlock, while the other two crew members wore spacesuits inside the airless capsule. Mr. Isaacman moved outside and conducted mobility tests of his spacesuit for a few minutes before re-entering the capsule. Ms Gillis then moved outside and performed the same tests.

This was the first of three Polaris missions aimed at accelerating technological advances needed to fulfill Mr. Musk’s dream of sending people to Mars someday. A key goal of the mission was to further the development of more advanced spacesuits that would be needed for SpaceX to try any future off-world colonization.

During a news conference before the launch, Mr. Isaacman mused that one day, someone might step onto Mars wearing a version of the spacesuit that SpaceX had developed for this flight. Closer to Earth, commercial spacewalks also present other possibilities, like technicians repairing private satellites in orbit.

During the spaceflight, the four astronauts conducted about 40 experiments, mostly about how weightlessness and radiation affect the human body. They also tested laser communications between the Crew Dragon and SpaceX’s constellation of Starlink internet satellites.

15-09-2024 om 22:29 geschreven door peter  

14-09-2024 om 23:58 geschreven door peter  

Getty / Futurism

Rocky Future

Don't panic, but the odds of a massive asteroid named Apophis smashing into Earth just got just a smidge higher.

Originally projected to harmlessly fly past us in a close approach, a new study published in The Planetary Science Journal suggests that there's actually a fraction of a chance that the 1,100-foot hunk of rock could collide with our planet after all, in the far off year of 2029.

The odds are less than one in a billion, fortunately, and would require the unfolding of a cosmic pool trick-shot to happen, but going from no chance to slim chance is still unnerving when we're talking about a mini-apocalypse on our hands.

Fortunately, Apophis — ominously named after the ancient Egyptian deity of Chaos — isn't considered big enough to wipe out human civilization outright, but it's certainly big enough to obliterate an entire city. But the real killer, most likely, will be the wait: we can't rule out the possibility of an impact until 2027, according to the study.

Bump Bump

First, we should note that Apophis, which astronomers have been observing since its discovery in 2004, isn't currently on a warpath for Earth. The study's sole author Paul Wiegert, an astronomer at Canada's Western University, found that it's still projected to fly past our planet at a distance of several Earth radii on April 13, 2029. Very close — it'll come between us and the Moon — but no cigar.

What's new, however, is the possibility that the trajectory could change if Apophis collides into another object along the way, like a smaller asteroid. According to Wiegert, almost none of the calculations on its trajectory so far have accounted for this happening since we haven't found any other asteroids that could cross paths with it. Even a study that did investigate this, which Wiegert published in March, found that the odds of this happening were "zero."

He's now recanting that. According to his latest findings, Wiegert says that Apophis could bump into tiny asteroids too small for us to see yet. If one of these wayward objects were just eleven feet across in size, that would be hefty enough to nudge it on a collision course with our planet in 2029.

And if it struck an object even just two feet across, it could also put it on a collision course — but at a later date, perhaps in 2036 or 2068.

Wait and See

Still, these impacts, even if they occur, would have to be perfectly placed to turn Apophis into an Earth-seeking missile. The odds, Wiegert calculated, is less than one in two billion. Even the odds of an impact occurring and causing a significant deflection — that doesn't necessarily put Apophis on a collision course — are less than one in one million.

Because Apophis is currently in the daytime sky, observing it with telescopes won't be possible until 2027. Even with a clear view, however, confirming that it was struck by something will be tricky, since by then most of the visible aftereffects will have dissipated, Wiegert wrote.

Still, he's optimistic that simple, direct observations of the asteroid that year will be enough to safely put the impact risk to rest — or perhaps to confirm our impending doom. Until then, it's out of our hands.

More on asteroids: 

• Debris From When NASA Smashed Asteroid Appears to Be Headed Back Toward Earth
  

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14-09-2024 om 22:53 geschreven door peter