Dit is ons nieuw hondje Kira, een kruising van een waterhond en een Podenko. Ze is sinds 7 februari 2024 bij ons en druk bezig ons hart te veroveren. Het is een lief, aanhankelijk hondje, dat zich op een week snel aan ons heeft aangepast. Ze is heel vinnig en nieuwsgierig, een heel ander hondje dan Noleke.
This is our new dog Kira, a cross between a water dog and a Podenko. She has been with us since February 7, 2024 and is busy winning our hearts. She is a sweet, affectionate dog who quickly adapted to us within a week. She is very quick and curious, a very different dog than Noleke.
DEAR VISITOR,
MY BLOG EXISTS ALREADY 13 YEARS AND 1 MONTH.
ON 06/07/2024 MORE THAN 2.101.500
VISITORS FROM 135 DIFFERENT NATIONS ALREADY FOUND THEIR WAY TO MY BLOG.
THAT IS AN AVERAGE OF 400GUESTS PER DAY.
THANK YOU FOR VISITING MY BLOG AND HOPE YOU ENJOY EACH TIME.
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.
Druk op onderstaande knop om te reageren in mijn forum
Zoeken in blog
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 In België had je vooral BUFON of het Belgisch UFO-Netwerk, dat zich met UFO's bezighoudt. BEZOEK DUS ZEKER VOOR ALLE OBJECTIEVE INFORMATIE , enkel nog beschikbaar via Facebook en deze blog.
Verder heb je ook het Belgisch-Ufo-meldpunt en Caelestia, die prachtig, doch ZEER kritisch werk leveren, ja soms zelfs héél sceptisch...
Voor Nederland kan je de mooie site www.ufowijzer.nl bezoeken van Paul Harmans. Een mooie site met veel informatie en artikels.
MUFON of het Mutual UFO Network Inc is een Amerikaanse UFO-vereniging met afdelingen in alle USA-staten en diverse landen.
MUFON's mission is the analytical and scientific investigation of the UFO- Phenomenon for the benefit of humanity...
Je kan ook hun site bekijken onder www.mufon.com.
Ze geven een maandelijks tijdschrift uit, namelijk The MUFON UFO-Journal.
Since 02/01/2020 is Pieter ex-president (=voorzitter) of BUFON, but also ex-National Director MUFON / Flanders and the Netherlands. We work together with the French MUFON Reseau MUFON/EUROP.
ER IS EEN NIEUWE GROEPERING DIE ZICH BUFON NOEMT, MAAR DIE HEBBEN NIETS MET ONZE GROEP TE MAKEN. DEZE COLLEGA'S GEBRUIKEN DE NAAM BUFON VOOR HUN SITE... Ik wens hen veel succes met de verdere uitbouw van hun groep. Zij kunnen de naam BUFON wel geregistreerd hebben, maar het rijke verleden van BUFON kunnen ze niet wegnemen...
23-07-2024
Why is Jupiter’s Great Red Spot Shrinking? It’s Starving.
Why is Jupiter’s Great Red Spot Shrinking? It’s Starving.
The largest storm in the Solar System is shrinking and planetary scientists think they have an explanation. It could be related to a reduction in the number of smaller storms that feed it and may be starving Jupiter’s centuries-old Great Red Spot (GRS).
This storm has intrigued observers from its perch in the Jovian southern hemisphere since it was first seen in the mid-1600s. Continuous observations of it began in the late 1800s, which allowed scientists to chart a constant parade of changes. In the process, they’ve learned quite a bit about the spot. It’s a high-pressure region that generates a 16,000 km-wide anticyclonic storm with winds clocking in at more than 321 km per hour. The storm extends down through the atmosphere to a depth of about 250 km below the mainly ammonia cloud tops.
Modeling a Shrinking and Growing Great Red Spot
Over the past century, scientists noticed the GRS shrinking, leaving them with a puzzle on their hands. Yale Ph.D. student Caleb Keaveney had the idea that perhaps smaller storms that feed the GRS could play a role in starving it. He and a team of researchers focused on their influence and conducted a series of 3D simulations of the Spot. They used a model called the Explicit Planetary Isentropic-Coordinate (EPIC) model, which is used in studying planetary atmospheres. The result was a suite of computer models that simulated interactions between the Great Red Spot and smaller storms of varying frequency and intensity.
A separate control group of simulations left out the small storms. Then, the team compared the simulations. They saw that the smaller storms seemed to strengthen the Great Red Spot and make it grow. “We found through numerical simulations that by feeding the Great Red Spot a diet of smaller storms, as has been known to occur on Jupiter, we could modulate its size,” Keaveney said.
If that’s true, then the presence (or lack thereof) of those smaller storms could be what’s changing the spot’s size. Essentially, a lot of smaller spots cause it to grow larger. Fewer little ones cause it to shrink. Furthermore, the team’s modeling supports an interesting idea. Without forced interactions with these smaller vortices, the Spot can shrink over a period of about 2.6 Earth years.
Using Earth Storms as a Comparison
The Great Red Spot isn’t the only place in the Solar System that sports such a long-lived high-pressure system. Earth experiences plenty of them, usually called “heat domes” or “blocks.” Most of us are familiar with heat domes because we experience them during the summer months. They happen frequently in the upper atmosphere jet stream that circulates across our planet’s mid-latitudes. We can blame them for some of the extreme weather people experience—such as heat waves and extended droughts. They tend to last a long time, and they are linked to interactions with smaller transient weather such as high-pressure eddies and anticyclones.
Given that the Great Red Spot is an anticyclonic feature, it has interesting implications for similar atmospheric structures on both planets, according to Keaveney. “Interactions with nearby weather systems have been shown to sustain and amplify heat domes, which motivated our hypothesis that similar interactions on Jupiter could sustain the Great Red Spot,” he said. “In validating that hypothesis, we provide additional support to this understanding of heat domes on Earth.”
The Ever-changing Great Red Spot
In addition to the changing size of the Great Red Spot, observers also notice shifts in its color. It’s mainly reddish-orange but has been known to fade to a pinkish-orange hue. The colors suggest some complex chemistry occurring in the region spurred by solar radiation. It has an effect on a chemical compound called ammonium hydrosulfide as well as the organic compound acetylene. That creates a substance called a tholin, which gives a reddish color wherever it exists.
At times the spot has nearly disappeared altogether due to some complex interaction with a feature called the Southern Equatorial Belt (SEB). The SEB is where the spot is located, and when it is bright and white, the spot goes dark. At other times, the reverse color change happens. In some cases, the SEB itself has disappeared at various times. No one is quite sure why this is happening, but it’s one more piece of the Jovian atmospheric puzzle.
Changes to the Great Red Spot have been studied extensively not just from the ground, but also by spacecraft missions, beginning with Voyager and extending through the Galileo, Cassini, and Juno missions. Each spacecraft used specialized instruments to probe the spot, measure its windspeeds and temperatures, and sample the gas and compounds in the upper atmosphere. All of that data feeds models like the ones used at Yale to model the smaller storms’ contributions to the Great Red Spot’s growth and shrinkage.
SpaceX Reveals the Beefed-Up Dragon That Will De-Orbit the ISS
The International Space Station (ISS) has been continuously orbiting Earth for more than 25 years and has been visited by over 270 astronauts, cosmonauts, and commercial astronauts. In January 2031, a special spacecraft designed by SpaceX – aka. The U.S. Deorbit Vehicle – will lower the station’s orbit until it enters our atmosphere and lands in the South Pacific. On July 17th, NASA held a live press conference where it released details about the process, including a first glance at the modified SpaceX Dragon responsible for deorbiting the ISS.
As usual, the company shared details about the press conference and an image of the special Dragon via their official X account (formerly Twitter). As they indicated, SpaceX will deploy a modified spacecraft that will have six times the propellant and four times the power of “their “today’s Dragon spacecraft.” The image shows that the U.S. Deorbit Vehicle will have a robust service module in place of the trunk used by the standard Crew Dragon vehicle. This module is larger and has additional fold-out solar arrays in addition to hull-mounted solar panels.
It also appears to have more Draco engines than the standard Crew Dragon vehicle – which has 18 engines capable of generating 400 Newtons (90 lbf) each – for a total of 7,200 N (360 lbf) of thrust. Presumably, this means the U.S. Deorbit Vehicle will have 72 Draco thrusters (arranged concentrically) and be capable of generating close to 30,000 Newtons (1,440 lbf) of thrust. The image also shows the spacecraft docking with the Kibo module operated by the Japan Aerospace Exploration Agency (JAXA).
NASA announced the selection of SpaceX in late June to develop the vehicle as part of a single-award contract with a total potential value of $843 million. While SpaceX is responsible for developing the spacecraft, NASA will take ownership once it is complete and operate it throughout the mission. Both the spacecraft and ISS are expected to break up during re-entry, and the remains will land in the “spacecraft cemetery” in the South Pacific. The contract for the launch services has not yet been awarded but is expected to be announced shortly.
SpaceX is also responsible for developing the Human Landing System (HLS) – the Starship HLS – that will transport astronauts to the lunar surface as part of the Artemis IIIand IV missions. SpaceX has also been contracted to launch the core elements of the Lunar Gateway – the Power and Propulsion Element (PPE) and the Habitation and Logistics Outpost (HALO) – into lunar orbit using a Falcon Heavy rocket in November 2025.
Since 1998, the ISS has served as a unique scientific platform where crew members from five space agencies – including NASA, the Canadian Space Agency), the European Space Agency (ESA), JAXA, and the Russian State Space Corporation (Roscosmos). During its operational lifetime, crew members have performed experiments ranging from the effects of microgravity and space radiation on human, animal, and plant physiology. This research will play a vital role as NASA and its international partners conduct long-duration missions to the Moon and Mars in the coming decades.
The station has also allowed for extensive research into space science, biology, the physical sciences, and technology demonstrations that are not possible on Earth. Above all, the ISS has served as a symbol of international cooperation, consistent with the Outer Space Treaty and its core philosophy of “space is for all.” NASA, the CSA, the ESA, and JAXA have all committed to operating the station through 2030, while Roscomos has committed to continue operations until 2028 at least. The safe deorbit of the ISS is the responsibility of all five space agencies.
The Entrance of a Lunar Lava Tube Mapped from Space
Craters are a familiar sight on the lunar surface and indeed on many of the rocky planets in the Solar System. There are other circular features that are picked up on images from orbiters but these pits are thought to be the collapsed roofs of lava tubes. A team of researchers have mapped one of these tubes using radar reflection and created the first 3D map of the tube’s entrance. Places like these could make ideal places to setup research stations, protected from the harsh environment of an alien world.
Lava tubes have been hotly debated for the last 50 years. They are the result of ancient volcanic activity and develop when the surface of a lava flow cools and hardens. Below this, the molten lava continues to move and eventually drains away leaving behind a hollow tunnel. Exploring these tunnels can mean we can learn more about the geological history of the Moon from the preserved records in the rocks.
The lava tubes have been the subject of analysis by NASA’s Lunar Reconnaissance Orbiter (LRO) which began its journey in 2009. It’s purpose was to gather information about the Moon’s surface and environment and to that end has a plethora of scientific equipment. LRO has been mapping the lunar surface using high resolution imagery capturing temperature, radiation levels and water ice deposits. All with a view to identifying potential landing sites for future missions.
A team of scientists from around the world have been working together to make a breakthrough in the quest to understand these tubes. The research was led by the University of Trento in Italy and the results published in Nature Astronomy. They have identified the first, confirmed tunnel just under the surface of the Moon that seems to be an empty lava tube. Until now, their existence was just a theory, now they are a reality.
The discovery would not have been possible without the LRO and its Miniature Radio-Frequency instrument. In 2010 it surveyed Mare Tranquilitatis – location for Apollo 11’s historic lunar landing in 1969 – capturing data which included the region around a pit. As part of this new research the data was reanalysed with modern complex signal processing techniques. The analysis revealed previously unidentified radar reflections that can best be explained by an underground cave or tunnel. Excitingly perhaps is that this represents an underground tunnel on the surface of the Moon but it is an accessible tunnel too.
The discovery highlights the importance of continued analysis of historical data, even from decades ago for hidden information that modern techniques can reveal. It also highlights the importance of further remote sensing and lunar exploration from orbit to identify more lava tubes as potential safe havens for lunar explorers.
Travellers to the Moon can experience temperatures on the illuminated side of 127 degrees down to -173 degrees on the night time side. Radiation from the Sun can rocket – pardon the pun – to 150 times more powerful than here on Earth and that’s not even considering the threat of meteorite impacts. We are protected from thousands of tonnes of the stuff thanks to the atmosphere but there is no protective shield on the Moon. If we build structures on the surface of the Moon then they must be built to withstand such a hostile environment but look to lava tubes and many of the problems naturally go away making it a far safer and cheaper prospect to establish a lunar presence.
Zwarte gaten ontsnappen aan de normale classificaties: we weten dat ze bestaan, misschien zelfs waar we ze niet verwachten, maar verder weten we er weinig van. Door de ruimte te observeren kunnen we doorgaans relatief gemakkelijk twee soorten zwarte gaten identificeren: sterrenmassa's gevormd door de ineenstorting van sterren en superzware, zoals het zwarte gat in het centrum van de Melkweg. Toch zijn er ook zwarte gaten met een middelzware massa, zeer zeldzaam maar ongelooflijk nuttig om de vorming en evolutie van deze hemellichamen te begrijpen. Een aantal onderzoekers hebben er misschien één ontdekt, verborgen achter een paar sterren die er niet zouden moeten zijn.
Het belang van zwarte gaten met middelzware massa
Zoals we in de inleiding al zeiden, vinden we in de ruimte meestal alleen zwarte gaten met stellaire massa en superzware zwarte gaten. Terwijl de eerstgenoemden een massa hebben die enkele tientallen malen groter is dan die van een ster, hebben de laatstgenoemden een massa die miljarden malen groter is dan die van de zon, net als Sagittarius A*. In het midden bevinden zich echter de zogenaamde Intermediate Mass Black Holes of IMBH, zwarte gaten met een massa tussen de ongeveer 100 en 100 duizend zonnemassa’s. Ze zijn essentieel voor het begrijpen van de overgang van kleinere naar grotere zwarte gaten en zijn zo zeldzaam dat het vinden ervan helemaal niet eenvoudig is. Zelfs als je het letterlijk voor ogen hebt.
Om deze reden is de ontdekking van astronomen van het Max Planck Instituut voor Astronomie in Duitsland historisch. Na twintig jaar aan gegevens van de Hubble-ruimtetelescoop te hebben geanalyseerd, merkten onderzoekers iets vreemds op in de Omega Centauri-regio, een cluster op 17.000 lichtjaar van ons verwijderd, waarin sommige sterren snel bewogen. Misschien wel te snel.
Zwart gat met middelzware massa gevonden in Omega Centauri
NASA Goddard/Youtube
Om te begrijpen hoe we een zwart gat met middelzware massa kunnen vinden, moeten we eerst begrijpen wat een bolvormige sterrenhoop is. Het is in feite een bolvormige formatie waarbinnen miljoenen sterren naast elkaar bestaan, maar over wiens oorsprong alleen maar vermoedens bestaan. Omega Centauri heeft bijvoorbeeld een doorsnede van 150 lichtjaar en zou kunnen vertegenwoordigen wat er overblijft van een dwergstelsel dat zich nu in de Melkweg bevindt. Net zoals de sterren van ons sterrenstelsel rond Sagittarius A* draaien, kunnen de sterren van Omega Centauri dus ook rond een zwart gat draaien. Maar welke?
In een studie gepubliceerd in Nature hebben onderzoekers van het Max Planck Instituut voor Astronomie bewijs gevonden voor deze dynamiek. Dankzij de door Hubble verzamelde beelden ontdekten ze vooral dat zeven sterren in de sterrenhoop zich met een grotere snelheid bewogen dan die van de sterrenhoop. Wat is de reden voor dit verschil? Het enige antwoord dat verenigbaar is met de waarnemingen is een zwart gat, maar met een middelzware massa.
Sterren die er niet zouden moeten zijn en zwarte gaten die niet gezien kunnen worden
Uit de uitgevoerde waarnemingen blijkt dat de nieuwe IMBH een massa heeft die minstens 8200 keer zo groot is als die van de zon, en kan helpen de vorming en evolutie van zwarte gaten in onze Melkweg te begrijpen. Dit zijn de woorden van de hoofdauteur van de studie, Maximilian Häberle:
We hebben zeven sterren ontdekt die er niet zouden moeten zijn. Ze bewegen zo snel dat ze de sterrenhoop zouden verlaten en nooit meer terugkeren. De meest waarschijnlijke verklaring is dat een zeer massief object deze sterren door de zwaartekracht aantrekt en ze dicht bij het centrum houdt. Het enige object dat zo massief kan zijn, is een zwart gat, met een massa die minstens 8200 keer zo groot is als die van onze zon.
Kortom, in Omega Centauri bevindt zich een zwart gat met een middelzware massa dat de ruimtetijd voldoende kan buigen om de relatieve snelheid van de sterren te vergroten. De ontdekking door het team van astronomen bevestigt verder de verscheidenheid aan zwarte gaten in onze Melkweg, maar vertegenwoordigt slechts het begin. Wie weet ontdekken we wel dat er een zwart gat dicht bij ons in de buurt is, aan de rand van het zonnestelsel of net daarbuiten.
NASA's Perseverance Rover Captures Snowman-Like Rock Formation on Mars
NASA's Perseverance Rover Captures Snowman-Like Rock Formation on Mars
Story by Mike Brown
Though this was not a predicted finding, NASA’s Perseverance rover has just snapped a picture of a snowman-like rock formation standing on Mars. This fanciful discovery, captured by the Right Mastcam-Z camera on 13 July 2024, set many minds racing at the imagination.
Since landing in Jezero Crater in February 2021, Perseverance has been studying the Martian surface relentlessly, taking pictures, and gathering rock samples. The latest picture, taken during Sol 1208 of the mission, contains the stack of rocks that are in the lower left corner, looking remarkably like a snowman. Though this “snowman” is made from dry, dusty Martian rock rather than fluffy snow, it serves to remind one that even in the desolate landscapes on Mars, sometimes familiar shapes can arise.
The discovery comes at a time when the Mars sample-return mission, a crucial component in the search for extraterrestrial life, faces budget overruns and significant delays. Notwithstanding that, the mission keeps returning insights regarding the geological history of Mars and its potential to support life.
NASA experts have, for a long time, proposed that there might be water on Mars. Because the atmosphere is extremely thin, very little water can stay in its liquid form on the surface. However, there are pieces of evidence of water ice existing at subsurface levels in the polar regions and briny water that flows down hillsides and crater walls seasonally, which opens up some very exciting possibilities regarding the past life of this planet and its ability to support life.
More than just the wacky “snowman” formation, this is something a bit more, a window into the dynamic climate and weather events taking place on Mars. It is the Red Planet, a place of dust storms, and extreme weather, and where an atmosphere thick enough once existed that liquid water could flow for long periods across its surface.
As Perseverance continues in its quest, it will leave behind the Jezero Crater, climb up the rim, and explore other areas. Every discovery, from a rock sample to some odd formation, helps to increase our knowledge of Mars and its habitability for future human exploration.
Another observer compared attaching sentimental shapes to Martian rocks with identifying animals in overhead clouds. Moments of imagination and wonder like this remind us of the endless possibilities that space exploration holds, even when technical and financial challenges for interplanetary missions come into play.
The car-sized NASA robot has spent much of 2024 exploring the Gediz Vallis channel, a dried-up waterway that travels down the three-mile-high Mount Sharp. Although Mars today is 1,000 times drier than the driest desert on Earth, the rover has spotted clues that long ago the Red Planet experienced momentous floods. It was a wet world.
"This was not a quiet period on Mars," Becky Williams, a scientist at the Planetary Science Institute who researches Mars using the rover's Mast Camera, said in a statement. "There was an exciting amount of activity here. We’re looking at multiple flows down the channel, including energetic floods and boulder-rich flows."
The images below show what Curiosity has recently found.
Below is a wide-view photo of a section of Gediz Vallis as it winds down Mount Sharp. You can see prominent buildups of rocks and boulders, such as those in the foreground on left. "This area was likely formed by large floods of water and debris that piled jumbles of rocks into mounds within the channel," NASA explained. Impressively, this debris pile-up extends some two miles down the mountain (though some of this was likely caused by landslides, too).
Mars' Gediz Vallis channel with large buildups of rocky debris.
Curiosity also closely examined these water-tumbled rocks. A number of them contain telltale "halo" markings, as seen in the image below. "Finally, water soaked into all the material that settled here," the space agency explained. "Chemical reactions caused by the water bleached white 'halo' shapes into some of the rocks."
At center, a Martian rock displaying a clear "halo" created by ancient interactions with water.
Unlike Earth, Mars no longer harbors an insulating atmosphere. The Red Planet's hot metallic core deep below its surface cooled long ago, and without a heated interior to generate a protective magnetic field, the once water-rich world was exposed to a relentless flow of particles from the sun, called the solar wind. The solar wind progressively stripped Mars of its thick atmosphere, leaving it the frigid, callous, irradiated desert we see today.
Related video:
NASA Calls Newest Mars Find 'Oasis' In The Desert (The Weather Channel)
The network of cracks in this Martian rock slab called "Old Soaker" may have formed from the drying of a mud layer more than 3 billion years ago. The view spans about 3 feet (90 centimeters) left-to-right and combines three images taken by the MAHLI camera on the arm of NASA's Curiosity Mars rover.› Full image and caption
Credit: NASA/JPL-Caltech/MSSS
The Curiosity rover, which landed on Mars in 2012, continues to scour Mars to determine if the planet could have ever harbored habitable conditions for microbial life. Meanwhile, NASA's Perseverance rover, which landed in 2020, is equipped with instruments that sleuth for hints of past life called "biosignatures" — elements, substances, or features providing evidence of ancient organisms. This could mean telltale chains of molecules or structures that were almost certainly produced by single-celled Martians.
Although it's clear that Mars once hosted bounties of water, robotic Martian explorers have spotted no evidence, so far, that this rocky world ever hosted life.
Pan around this 360-degree video to explore Gediz Vallis channel, the location where NASA’s Curiosity Mars rover discovered sulfur crystals and drilled its 41st rock sample. The images that make up this mosaic were captured by the rover’s MastCam in June.
Credit: NASA/JPL-Caltech/MSSS
Credit: NASA / JPL-Caltech / ASU / MSSS
Credit: NASA / JPL-Caltech / ASU
Credit: NASA / JPL-Caltech / University of Arizona
NASA’s Curiosity Rover Discovers a Surprise in a Martian Rock
NASA’s Curiosity Rover Discovers a Surprise in a Martian Rock
These yellow crystals were revealed after NASA's Curiosity happened to drive over a rock and crack it open on May 30. Using an instrument on the rover's arm, scientists later determined these crystals are elemental sulfur—and it's the first time this kind of sulfur has been found on the Red Planet.
NASA’s Curiosity captured this close-up image of a rock nicknamed “Snow Lake” on June 8, 2024, the 4,209th Martian day, or sol, of the mission. Nine days earlier, the rover had crushed a similar-looking rock and revealed crystalline textures—and elemental sulfur—inside.
Among several recent findings, the rover has found rocks made of pure sulfur — a first on the Red Planet.
Scientists were stunned on May 30 when a rock that NASA’s Curiosity Mars rover drove over cracked open to reveal something never seen before on the Red Planet: yellow sulfur crystals.
Since October 2023, the rover has been exploring a region of Mars rich with sulfates, a kind of salt that contains sulfur and forms as water evaporates. But where past detections have been of sulfur-based minerals — in other words, a mix of sulfur and other materials — the rock Curiosity recently cracked open is made of elemental, or pure, sulfur. It isn’t clear what relationship, if any, the elemental sulfur has to other sulfur-based minerals in the area.
While people associate sulfur with the odor from rotten eggs (the result of hydrogen sulfide gas), elemental sulfur is odorless. It forms in only a narrow range of conditions that scientists haven’t associated with the history of this location. And Curiosity found a lot of it — an entire field of bright rocks that look similar to the one the rover crushed.
“Finding a field of stones made of pure sulfur is like finding an oasis in the desert,” said Curiosity’s project scientist, Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Southern California. “It shouldn’t be there, so now we have to explain it. Discovering strange and unexpected things is what makes planetary exploration so exciting.”
It’s one of several discoveries Curiosity has made while off-roading within Gediz Vallis channel, a groove that winds down part of the 3-mile-tall (5-kilometer-tall) Mount Sharp, the base of which the rover has been ascending since 2014. Each layer of the mountain represents a different period of Martian history. Curiosity’s mission is to study where and when the planet’s ancient terrain could have provided the nutrients needed for microbial life, if any ever formed on Mars.
NASA’s Curiosity Mars rover captured this view of Gediz Vallis channel on March 31. This area was likely formed by large floods of water and debris that piled jumbles of rocks into mounds within the channel.
NASA/JPL-Caltech/MSSS
Floods and Avalanches
Spotted from space years before Curiosity’s launch, Gediz Vallis channel is one of the primary reasons the science team wanted to visit this part of Mars. Scientists think that the channel was carved by flows of liquid water and debris that left a ridge of boulders and sediment extending 2 miles down the mountainside below the channel. The goal has been to develop a better understanding of how this landscape changed billions of years ago, and while recent clues have helped, there’s still much to learn from the dramatic landscape.
Since Curiosity’s arrival at the channel earlier this year, scientists have studied whether ancient floodwaters or landslides built up the large mounds of debris that rise up from the channel’s floor here. The latest clues from Curiosity suggest both played a role: some piles were likely left by violent flows of water and debris, while others appear to be the result of more local landslides.
While exploring Gediz Vallis channel in May, NASA’s Curiosity captured this image of rocks that show a pale color near their edges. These rings, also called halos, resemble markings seen on Earth when groundwater leaks into rocks along fractures, causing chemical reactions that change the color.
NASA/JPL-Caltech/MSSS
Those conclusions are based on rocks found in the debris mounds: Whereas stones carried by water flows become rounded like river rocks, some of the debris mounds are riddled with more angular rocks that may have been deposited by dry avalanches.
Finally, water soaked into all the material that settled here. Chemical reactions caused by the water bleached white “halo” shapes into some of the rocks. Erosion from wind and sand has revealed these halo shapes over time.
“This was not a quiet period on Mars,” said Becky Williams, a scientist with the Planetary Science Institute in Tucson, Arizona, and the deputy principal investigator of Curiosity’s Mast Camera, or Mastcam. “There was an exciting amount of activity here. We’re looking at multiple flows down the channel, including energetic floods and boulder-rich flows.”
A Hole in 41
All this evidence of water continues to tell a more complex story than the team’s early expectations, and they’ve been eager to take a rock sample from the channel in order to learn more. On June 18, they got their chance.
While the sulfur rocks were too small and brittle to be sampled with the drill, a large rock nicknamed “Mammoth Lakes” was spotted nearby. Rover engineers had to search for a part of the rock that would allow safe drilling and find a parking spot on the loose, sloping surface.
After Curiosity bored its 41st hole using the powerful drill at the end of the rover’s 7-foot (2-meter) robotic arm, the six-wheeled scientist trickled the powderized rock into instruments inside its belly for further analysis so that scientists can determine what materials the rock is made of.
Curiosity has since driven away from Mammoth Lakes and is now off to see what other surprises are waiting to be discovered within the channel.
More About the Mission
Curiosity was built by NASA’s Jet Propulsion Laboratory, which is managed by Caltech in Pasadena, California. JPL leads the mission on behalf of NASA’s Science Mission Directorate in Washington.
Wetenschappers waren verbaasd toen een steen waar Marsrover Curiosity overheen reed, barstte en iets onthulde dat nog nooit eerder op de rode planeet is gezien: gele zwavelkristallen.
Sinds oktober 2023 verkent het Marswagentje Curiosity een gebied op Mars dat rijk is aan sulfaten, een type zout dat zwavel bevat en ontstaat wanneer water verdampt. Toch waren onderzoekers zeer verrast toen ze een betere blik wierpen op een steen die Curiosity per ongeluk had opengebroken. Curiosity had onverwacht gesteenten gevonden die uit puur zwavel bestaan – een unicum op de rode planeet.
Gele zwavelkristallen Hieronder is de foto van de gele zwavelkristallen te aanschouwen. Waar eerdere ontdekkingen zwavelhoudende mineralen betroffen – dus een mix van zwavel en andere materialen – bestaat het gesteente dat hieronder te zien is uit elementaire, oftewel pure, zwavel. Het is nog onduidelijk welke relatie, als die er is, deze pure zwavel heeft met de andere zwavelhoudende mineralen in het gebied.
Zwavel Curiosity hoeft in de buurt van deze gele zwavelkristallen gelukkig zijn neus niet dicht te houden. Hoewel zwavel vaak wordt geassocieerd met de geur van rotte eieren (door waterstofsulfidegas), is pure zwavel geurloos. Het opmerkelijke is alleen dat het zich vormt onder een beperkte reeks omstandigheden die wetenschappers nog niet eerder hadden gekoppeld aan de geschiedenis van de vindplaats. Bovendien vond Curiosity er veel van: het lag verspreid over een veld van heldere gesteenten die lijken op het gesteente waar de rover overheen reed.
Oase Missieleden kunnen hun geluk niet op. “Het ontdekken van een veld met stenen van puur zwavel is vergelijkbaar met het vinden van een oase in de woestijn,” legt missie-lid Ashwin Vasavada uit. “Het zou daar eigenlijk niet moeten zijn, dus we moeten nu uitzoeken hoe dat zo is gekomen. Het vinden van zulke vreemde en onverwachte dingen maakt planetaire verkenning zo opwindend.”
Ontdekkingen De ontdekking van de gele zwavelkristallen kan worden toegevoegd aan de toch al indrukwekkende lijst van bijzondere vondsten die Curiosity heeft gedaan. Tijdens zijn verkenning van het Gediz Vallis-kanaal, een sleuf die langs een deel van de vijf kilometer hoge Mount Sharp slingert en waarvan de rover de basis sinds 2014 beklimt, stuitte hij al op veel verrassingen. Elke laag van de berg vertegenwoordigt een verschillende periode in de geschiedenis van Mars. Curiosity’s missie is om te onderzoeken waar en wanneer het oude oppervlak van de planeet mogelijk de voedingsstoffen heeft geboden die nodig zijn voor microbiologisch leven, mocht er ooit leven op Mars zijn geweest.
Gediz Vallis-kanaal Het Gediz Vallis-kanaal werd jaren vóór de lancering van Curiosity al vanuit de ruimte opgemerkt en is een van de belangrijkste redenen waarom het wetenschappelijk team dit deel van Mars wilde verkennen. Wetenschappers geloven dat het kanaal is gevormd door stromen van vloeibaar water en puin, die een richel van keien en sediment hebben achtergelaten die zich ongeveer drie kilometer langs de berghelling onder het kanaal uitstrekt. Het doel is om beter te begrijpen hoe dit landschap miljarden jaren geleden is veranderd. Hoewel recente ontdekkingen nuttig zijn geweest, is er nog veel te leren van dit indrukwekkende landschap.
Grote hopen puin Sinds Curiosity dit jaar bij het kanaal arriveerde, hebben wetenschappers onderzocht of oude overstromingen of aardverschuivingen verantwoordelijk zijn voor de grote hopen puin die vanuit de bodem van het kanaal omhoog komen. De meest recente gegevens van Curiosity wijzen erop dat beide factoren een rol hebben gespeeld: sommige hopen zijn waarschijnlijk ontstaan door heftige water- en puinstromen, terwijl andere mogelijk het gevolg zijn van meer lokale aardverschuivingen. Deze conclusies zijn gebaseerd op de stenen die in de puinhopen zijn aangetroffen: stenen die door waterstromen zijn meegenomen, zijn vaak afgerond zoals rivierstenen, terwijl sommige puinhopen juist vol zitten met hoekigere stenen die mogelijk zijn afgezet door droge lawines.
Water Uiteindelijk heeft water zich door al het materiaal dat hier is neergeslagen, verspreid. Chemische reacties door het water hebben in sommige stenen witte ‘halo’-vormen veroorzaakt. Erosie door wind en zand heeft deze halo-vormen door de tijd heen zichtbaar gemaakt. “Dit was geen rustige periode op Mars,” zegt onderzoeker Becky Williams. “We zien verschillende stromen door het kanaal, waaronder krachtige overstromingen en stromen vol puin.” Kortom, deze bevindingen suggereren dat Mars in het verleden een veel actievere planeet was dan eerder werd aangenomen, met periodes van gewelddadige overstromingen en aardverschuivingen die het landschap vormden.
Mammoth Lakes Al dit watergerelateerde bewijs onthult een complexer verhaal dan het team aanvankelijk had verwacht. Ze waren dan ook enthousiast om een gesteentemonster uit het kanaal te halen om meer te ontdekken. Hoewel de zwavelstenen te klein en breekbaar waren om met de boor te worden bemonsterd, werd in de buurt een grote steen met de bijnaam ‘Mammoth Lakes’ gevonden. Missieleden moesten een geschikt gedeelte van de steen vinden om veilig te kunnen boren en een geschikte plek op het losse, hellende oppervlak zoeken om te parkeren. Nadat Curiosity zijn 41e gat had geboord met de krachtige boor aan het einde van de twee meter lange robotarm, werd het poederige gesteente verzameld in de instrumenten in de rover voor verdere analyse. Dit stelt wetenschappers in staat om te bepalen uit welke materialen het gesteente is samengesteld.
Al met al hebben de ontdekkingen van de Curiosity rover in het Gediz Vallis-kanaal het inzicht in de geologische geschiedenis van Mars aanzienlijk verdiept. En elke nieuwe vondst brengt wetenschappers dichter bij het ontrafelen van de vraag of Mars ooit de voorwaarden heeft gekend die nodig zijn voor microbiologisch leven. Curiosity heeft Mammoth Lakes inmiddels verlaten en is nu op pad om te kijken welke andere verrassingen er in het kanaal op ontdekking wachten.
Hoe hard de aarde om haar as draait, wordt normaal gesproken voornamelijk geregeld door de maan, die al miljarden jaren de lengte van een dag bepaalt. Maar dat gaat veranderen: klimaatverandering heeft straks een nog grotere invloed op de rotatiesnelheid van onze planeet.
De opwarming van de aarde zorgt ervoor dat de ijskappen in Groenland en op Antarctica smelten. Dit water stroomt van de poolgebieden naar de oceanen, vooral richting de evenaar. “Dat betekent dat er een enorme verschuiving van massa plaatsvindt, die de rotatie van de aarde beïnvloedt”, legt hoogleraar Benedikt Soja van de ETH Zurich uit.
De pirouettes van een kunstschaatsster “Het is net als wanneer een kunstschaatsster een pirouette maakt: eerst houdt ze haar armen dicht bij haar lichaam en vervolgens strekt ze ze uit”, vertelt Soja metaforisch. Daardoor gaat ze steeds langzamer ronddraaien, omdat de massa – in dit geval haar armen – zich verder van de rotatie-as, haar lichaam dus, bevindt. Zo gaat ook de aarde steeds langzamer draaien, doordat de massa verder wegdrijft van de polen richting de evenaar, het breedste punt van de aardbol.
In de natuurkunde noemen ze dat de wet van behoud van het hoekmoment, en die geldt ook voor de rotatie van de aarde. Als de aarde langzamer draait, worden de dagen langer. Klimaatverandering verandert dus de lengte van een dag, zij het minimaal. Volgens de Zwitserse onderzoekers scheelt het enkele milliseconden, maar toch.
Niet alleen de maan Dit komt dus enerzijds doordat water van de polen naar lagere breedtegraden stroomt en zo de rotatiesnelheid vertraagt. Een andere oorzaak is het effect van de getijden, veroorzaakt door de maan. Ooit was dat de enige invloed, nu lijkt het van secundair belang te worden. De studie komt namelijk tot de conclusie dat als we niets doen, klimaatverandering uiteindelijk een grotere impact heeft op de rotatiesnelheid van de aarde dan de maan, die al miljarden jaren de daglengte bepaalt. “Wij mensen hebben een grotere impact op onze planeet dan we ons realiseren”, reageert Soja. “Dit geeft ons uiteraard een enorme verantwoordelijkheid voor de toekomst van de aarde.”
De massaverschuivingen op het aardoppervlak, veroorzaakt door het smeltende ijs, veranderen niet alleen de rotatiesnelheid en de daglengte, maar ook de as van de aarde. De punten waar de rotatieas het oppervlak bereikt, zijn aan het verschuiven. Op de lange termijn leidt dit tot een verplaatsing van de as van 10 meter per 100 jaar. Dat komt overigens niet alleen door de smeltende ijskappen, ook de bewegingen in het binnenste van de aarde spelen een rol.
Stroperig gesteente Diep in de aardmantel, waar het gesteente door hoge druk stroperig wordt, verschuift eveneens het een en ander in de loop van duizenden jaren. Verder zorgen hittestromen van vloeibaar metaal in de buitenkern van de aarde voor massaverschuivingen. De verplaatsing van de polen en de afnemende rotatiesnelheid worden dus veroorzaakt door processen in de aardkern, de mantel en door het klimaat aan het oppervlak, blijkt uit het grootste model tot nu toe.
“Voor het eerst is er een volledige verklaring voor de oorzaken van de polaire beweging”, zegt hoofdonderzoeker Mostafa Kiani Shahvandi. “Met andere woorden, we weten nu waarom en hoe de rotatie-as van de aarde verschuift ten opzichte van de aardkorst.” Een opvallende bevinding is dat de processen op en in de aarde met elkaar verbonden zijn en elkaar beïnvloeden. “Klimaatverandering zorgt ervoor dat de as van de aarde beweegt, en het lijkt erop dat de terugkoppeling van het behoud van het hoekmoment ook de dynamiek van de aardkern verandert”, legt Soja uit. Kiani Shahvandi voegt toe: “Aanhoudende klimaatverandering kan dus zelfs de processen diep in de aarde beïnvloeden en een grotere reikwijdte hebben dan eerder aangenomen.”
Nieuwe AI geeft kijkje in de toekomst Voor hun studie gebruikten de onderzoekers nieuwe AI-methoden waarbij ze de wetten en principes van de natuurkunde toepasten om bijzonder krachtige en betrouwbare algoritmen voor machinelearning te ontwikkelen. Daarmee was het voor het eerst mogelijk om alle verschillende effecten op het aardoppervlak, in de mantel en in de kern vast te stellen en hun mogelijke interacties in kaart te brengen. Het resultaat van de berekeningen laat zien hoe de rotatiepolen van de aarde sinds 1900 zijn verschoven. Dit sluit uitstekend aan bij satellietwaarnemingen van de afgelopen dertig jaar, waardoor er nu ook goede prognoses voor de toekomst kunnen worden gemaakt.
Hoewel een kleine verschuiving niet erg lijkt, is het ook niet geheel zonder gevolgen. “Zelfs als de rotatie van de aarde maar langzaam verandert, moet daarmee rekening worden gehouden bij het navigeren in de ruimte, bijvoorbeeld als een ruimtevaartuig op een andere planeet moet landen. Een kleine afwijking van slechts 1 centimeter op aarde kan al leiden tot een afwijking van honderden meters over de enorme afstanden in de ruimte. Anders zal het niet mogelijk zijn om in een specifieke krater op Mars te landen”, klinkt het.
De invloed van klimaatverandering is dus complexer dan gedacht, stellen de onderzoekers. Zelfs bij landingen op andere planeten miljoenen kilometers hiervandaan moeten we er rekening mee houden.
What happens when a spiral and an elliptical galaxy collide? To celebrate the second anniversary of the “first light” for the Webb telescope, NASA released an amazing infrared view of two galaxies locked in a tight dance. They’re called the Penguin and the Egg and their dance will last hundreds of millions of years.
“In just two years, Webb has transformed our view of the universe, enabling the kind of world-class science that drove NASA to make this mission a reality,” said Mark Clampin, director of the Astrophysics Division at NASA Headquarters in Washington. “Webb is providing insights into longstanding mysteries about the early Universe.”
Webb Witnesses a Galactic Dance
The telescope targeted a collision scene named Arp 142 containing both galaxies—a scene that the Hubble Space Telescope has also explored. They lie about 326 million light-years away. Their first close encounter began somewhere between 25 and 75 million years ago. That’s when two partner galaxies had the first of many passages that will distort their shapes more than they already appear here.
Webb’s observations, which combine near- and mid-infrared light from Webb’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument), respectively, clearly show that a hazy cloud of gas and stars (blue) links them together. The close approach also set off tremendous bursts of star birth in the colliding clouds of gas and dust.
Eventually, after several close approaches in their cosmic dance, these two galaxies will merge completely. Observers hundreds of millions of years in the future will look at Arp 142 and see one massive elliptical galaxy.
Interestingly, Webb’s sharp infrared eyes also picked out very distant galaxies. Some lie beyond this cosmic collision, although at least one lies about a hundred million light-years closer to Earth. It bristles with hot, young, newborn stars.
How The Arp 142 Galaxies Experience a Merger
The Penguin and Egg galaxies lie about 100,000 light-years apart but they affect each other. The Egg’s gravitational pull distorts the spiral and that interaction is “sculpting” the Penguin. The core makes up the eye of a penguin. The slowly unwinding spiral arms form a beak, head, backbone, and tail.
Webb’s infrared view reveals otherwise unseen activity between the two. For example, the Penguin is rich in dust. Webb’s view shows us how gravitational interactions pull that dust away from the Penguin. There are also scads of new stars in the galaxy, surrounded by what looks like smoke. Webb’s view shows this hydrogen cloud. It’s rich in carbon-based molecules called polycyclic aromatic hydrocarbons (PAHs). These are incredibly abundant in the Universe and astronomers find them just about everywhere they point a telescope.
By contrast, in Webb’s view, the Egg looks like it’s hardly been touched—it’s still an egg-shaped elliptical. It has much older stars than the Penguin. Past epochs of star birth have pretty much used up the available star-making material. So, even though the two galaxies have about the same mass, the Egg just doesn’t have as much material to get stretched out or turned into stars.
Zeroing in on Webb’s Two Views
If you look at both of Webb’s infrared views of the galaxy collision, you can see marked differences in them. That’s because each one prioritizes a different set of infrared wavelengths. In the mid-infrared view, the egg looks tiny and washed out. That’s because the instrument sees only the old stars in the Egg. By contrast, the Penguin’s distorted core and spiral arms are brimming with young stars embedded in the PAH-rich hydrogen clouds.
The combined near- and mid-infrared view shows more of the gas clouds as the Egg tears them away from the Penguin. These regions will glitter in the future with the light of newly formed stars. For now, however, only cooler, older stars are visible in the combined image. The younger ones are there, but the mid-infrared-sensitive instrument doesn’t spot them.
Why Does Webb Study Galaxy Collisions?
By studying this galactic collision site, the Webb telescope further probes the activity as galaxies evolve. Collisions are an integral part of this process. Our Milky Way Galaxy will dance with the nearby Andromeda Galaxy, starting in about 5 billion years. Images and data from observations of other galaxies doing the same thing give astronomers a chance to understand the process and forecast the distant future when something called “Milkdromeda” will contain the stars and planets of two spirals that once were close neighbors.
A Walking Balloon Could One Day Explore Titan – Or Earth’s Sea Floor
Novel ways to move on other celestial bodies always draw the attention of the space exploration community. Here at UT, we’ve reported on everything from robots that suspend themselves from the walls of Martian caves to robots that hop using jets of locally mined gas. But we haven’t yet reported on the idea of a balloon that “walks.” But that is the idea behind the BALloon Locomotion for Extreme Terrain, or BALLET, a project from Hari Nayar, a Principal Roboticist at NASA’s Jet Propulsion Laboratory, and his colleagues.
How exactly does a balloon “walk,” you might ask? By picking up and moving one of its six feet. BALLET’s architecture involves a positively buoyant balloon supporting six “feet” attached to adjustable cables. The “feet” are small science packages capable of taking small surface samples or analyzing the chemical composition of the part of the surface it touches.
Each foot is attached to three cables, individually controlled by pulleys. When a foot is done doing its science work at a given location, BALLET retracts the cables for the foot, lifting it off the surface. It then extends the cables using different lengths for the cables to place the foot in a new location.
Preliminary research on the concept was done as part of a NASA Institute for Advanced Concepts (NIAC) grant in 2018. That research showed that it was better to lift two opposing feet off the ground at the same time to ensure the balloon’s stability. It also demonstrated where the concept would be most useful—Titan.
Balloon locomotion is typically considered somewhere like Venus, where it could float in the atmosphere in conditions similar to Earth. However, that altitude would make controlling a payload placed on the ground exceedingly tricky. Additionally, the harsh conditions close enough to the ground to be feasible would make the material requirements of the system untenable.
Similarly, a balloon could also work on Mars, but the high wind speeds of the sparse atmosphere would make controlling the balloon difficult. Titan offers the best of both worlds – a relatively stable, thick atmosphere where a negatively buoyant balloon would be feasible and stable environmental conditions that wouldn’t blow BALLET everywhere.
It also has many interesting places to explore, including cryovolcanoes and methane lakes. BALLET would allow traversal over even some of the most difficult terrain without accounting for considerations that would dramatically affect the capabilities of either a rover or a helicopter, such as the planned Dragonfly mission.
There are still plenty of design considerations, though, such as the difficulty of controlling all the different variables, such as balloon orientation, cable length for each of the 18 cables, and pathfinding, simultaneously. After the completion of the Phase I project, the concept appears to be on hold in terms of receiving further funding from NASA at this point.
However, in terms of applications, BALLET also has some obvious ones on Earth. One that immediately sprang to mind is the collection of “nodules” as part of an undersea mining operation. Given the increased need for cobalt and other materials provided in those nodules and the bad image that comes from the destruction of the seabed that comes with traditional mining techniques, this idea might be one of those rare space exploration ideas that sooner sees an application on Earth than off of it.
Experimental Radar Technique Reveals the Composition of Titan’s Seas
The Cassini-Huygens mission to Saturn generated so much data that giving it a definitive value is impossible. It’s sufficient to say that the amount is vast and that multiple scientific instruments generated it. One of those instruments was a radar designed to see through Titan’s thick atmosphere and catch a scientific glimpse of the moon’s extraordinary surface.
Scientists are still making new discoveries with all this data.
Though Saturn has almost 150 known moons, Titan attracts almost all of the scientific attention. It’s Saturn’s largest moon and the Solar System’s second largest. But Titan’s surface is what makes it stand out. It’s the only object in the Solar System besides Earth with surface liquids.
Cassini’s radar instrument had two basic modes: active and passive. In active mode, it bounced radio waves off surfaces and measured what was reflected back. In passive mode, it measured waves emitted by Saturn and its moons. Both of these modes are called static modes.
But Cassini had a third mode called bistatic mode that saw more limited use. It was experimental and used its Radio Science Subsystem (RSS) to bounce signals off of Titan’s surface. Instead of travelling back to sensors on the spacecraft, the signals were reflected back to Earth, where they were received at one of NASA’s Deep Space Network (DNS) stations. Critically, after bouncing off of Titan’s surface, the signal was split into two, hence the name bistatic.
The signals that reach the DNS are polarized, which reveals more information about the hydrocarbon seas on Titan. While Cassini’s radar instrument revealed how deep the seas are, the bistatic radar data tells researchers about both their compositions and surface textures.
“The main difference,” Poggiali said, “is that the bistatic information is a more complete dataset, and is sensitive to both the composition of the reflecting surface and to its roughness.”
The experimental bistatic radar required meticulous cooperation.
Philip Nicholson, a professor in the Department of Astronomy at Cornell, is one of the study’s co-authors. “The successful execution of a bistatic radar experiment requires exquisite choreography between the scientists who design it, Cassini mission planners and navigators, and the team who collects the data at the receiving station,” Nicholson said.
These results are based on bistatic radar data from four Cassini flybys from 2014 to 2016. In this work, the researchers focused on three large seas on the surface of Titan’s polar regions: Kraken Mare, Ligeia Mare and Punga Mare.
The bistatic radar data revealed new information about the three seas. Though they’re all hydrocarbon seas, their composition varies based on latitude and their proximity to other features like estuaries and rivers. The bistatic radar measured the dielectric constant of Titan’s seas. The dielectric constant is a material’s capacity to store electrical energy. In practical terms, it’s a measure of a surface’s reflectivity, so it reveals the composition. Earth’s water has a dielectric constant of about 80. Titan’s methane and ethane seas have a dielectric constant of only about 1.7. Kraken Mare’s southernmost region had the highest dielectric constant.
Bistatic radar data also showed all three seas had calm surfaces during the four flybys. Waves were no more than 3.3 mm, about 0.13 of an inch. Near estuaries, straits, and coastal areas, the waves were slightly larger: 5.2 mm or 0.2 of an inch. So small they barely merit the name ‘wave.’
The bistatic radar data also revealed the composition of some of the rivers that flow into the seas.
“We also have indications that the rivers feeding the seas are pure methane,” Poggiali said, “until they flow into the open liquid seas, which are more ethane-rich. It’s like on Earth, when fresh-water rivers flow into and mix with the salty water of the oceans.”
These results agree with scientific models of Titan’s hydrocarbon seas and thick atmosphere. Models show that methane rains down from Titan’s atmosphere and then flows into its lakes and seas. They also show that the rain contains only tiny amounts of ethane and other hydrocarbons and almost completely consists of methane.
“This fits nicely with meteorological models for Titan,” Nicholson said, “which predict that the ‘rain’ that falls from its skies is likely to be almost pure methane, but with trace amounts of ethane and other hydrocarbons.”
The Cassini mission is very instructive for future missions. Though it ended its mission when it plunged into Saturn in 2017, scientists are still making new discoveries with its vast trove of data. The same will be true of missions like Juno when they end.
The researchers behind this work say there’s lots left to learn from all of Cassini’s data.
“There is a mine of data that still waits to be fully analyzed in ways that should yield more discoveries,” Poggiali said. “This is only the first step.”
ESA is Building a Mission to Visit Asteroid Apophis, Joining it for its 2029 Earth Flyby
According to the ESA’s Near-Earth Objects Coordination Center (NEOCC), 35,264 known asteroids regularly cross the orbit of Earth and the other inner planets. Of these, 1,626 have been identified as Potentially Hazardous Asteroids (PHAs), meaning that they may someday pass close enough to Earth to be caught by its gravity and impact its surface. While planetary defense has always been a concern, the comet Shoemaker-Levy 9slamming into Jupiter in 1994 sparked intense interest in this field.
In 2022, NASA’s Double-Asteroid Redirect Test (DART) mission successfully tested the kinetic impact method when it collided with Dimorphos, the small asteroid orbiting Didymos. Today, the ESA Space Safety program is taking steps to test the next planetary defense mission – the Rapid Apophis Missin for Space Safety (RAMSES). In 2029, RAMSES will rendezvous with the Near Earth Asteroid (NEA) 99942 Apophis and accompany it as it makes a very close (but safe) flyby of Earth in 2029. The data it collects will help scientists improve our ability to protect Earth from similar objects that could pose an impact risk.
Discovered in 2004, Apophis is an irregularly shaped asteroid measuring about 375 m (410 yards) across. At the time, observations indicated there was a small risk that it would impact Earth in 2029, 2036, or 2068. Given its size and the devastating effect an impact would have, astronomers decided to name it after the Egyptian god of chaos and destruction. While astronomers have since ruled out the possibility of a collision for at least the next century, Apophis will pass within 32,000 km (~19,885 mi) of Earth’s surface on April 13th, 2029.
At this distance, the asteroid will be close enough to be visible to the naked eye to roughly two billion people across much of Europe, Africa, and parts of Asia. Based on analyses of the size and orbits of all known asteroids, astronomers believe that objects this large pass this close to Earth only once every 5,000 to 10,000 years. The RAMSES spacecraft will rendezvous with Apophis before it makes its closest pass to Earth and follow behind, monitoring it with a suite of scientific instruments to see how Earth’s gravity changes it.
This will consist of conducting before-and-after surveys of the asteroid’s shape, surface, orbit, rotation, and orientation. Based on this comparative analysis, scientists will learn more about how an asteroid’s fundamental characteristics – its composition, interior structure, cohesion, mass, density, and porosity – respond to external forces. These properties are vital for determining how to knock a PHA off course so it does not collide with Earth. Patrick Michel, the Director of Research at the Centre national de la recherche scientifique (CNRS) and the Observatoire de la Côte d’Azur in Nice, explained in an ESA press release:
“There is still so much we have yet to learn about asteroids but, until now, we have had to travel deep into the Solar System to study them and perform experiments ourselves to interact with their surface. For the first time ever, nature is bringing one to us and conducting the experiment itself. All we need to do is watch as Apophis is stretched and squeezed by strong tidal forces that may trigger landslides and other disturbances and reveal new material from beneath the surface.”
The ESA recently secured permission from the Space Safety Program board to begin preparatory work on the mission so it can launch by April 2028. This deadline is necessary, so the mission is to be ready to launch and rendezvous with Apophis in orbit by February 2029. The final decision to commit to the mission will be made at the ESA’s Ministerial Council Meeting in November 2025. In the meantime, NASA has redirected its newly renamed OSIRIS-APEX spacecraft towards Apophis, which will arrive one month after the asteroid makes its flyby.
Since asteroids are leftover material from the formation of the Solar System (ca. 4.5 billion years ago), this rendezvous is also an opportunity to obtain data that could provide new insights into planetary formation and evolution. This makes the 2029 flyby an extremely rare opportunity for astronomy, asteroid science, planetary defense, and for engaging billions of people worldwide. It will also be an opportunity for international collaboration, as previously demonstrated by the DART and the ESA’s Hera missions – the former redirected Didymos while the latter confirmed a change in orbit.
Last, but not least, the RAMSES mission will test the ability of space agencies to build and deploy an asteroid response quickly. As Richard Moissl, heading ESA’s Planetary Defence Office, explained:
“Ramses will demonstrate that humankind can deploy a reconnaissance mission to rendezvous with an incoming asteroid in just a few years. This type of mission is a cornerstone of humankind’s response to a hazardous asteroid. A reconnaissance mission would be launched first to analyse the incoming asteroid’s orbit and structure. The results would be used to determine how best to redirect the asteroid or to rule out non-impacts before an expensive deflector mission is developed.”
NASA Stops Work on VIPER Moon Rover, Citing Cost and Schedule Issues
NASA says it intends to discontinue development of its VIPER moon rover, due to cost increases and schedule delays — but the agency is also pointing to other opportunities for robotic exploration of the lunar south polar region.
The Volatiles Investigating Polar Exploration Rover was originally scheduled for launch in late 2023, targeting the western edge of Nobile Crater near the moon’s south pole.
The south polar region is a prime target for exploration because it’s thought to hold deposits of water ice that could sustain future lunar settlements. NASA plans to send astronauts to that region by as early as 2026 for the first crewed lunar landing since 1972.
Unfortunately, the VIPER project ran into a series of delays, due to snags in the testing and development of the rover as well as the Astrobotic Griffin lander that was to deliver the rover to the lunar surface. The readiness date for VIPER and Griffin was most recently pushed back to September 2025.
During an internal review, NASA managers decided that continuing with VIPER’s development would result in cost increases that could lead to the cancellation or disruption of other moon missions in NASA’s Commercial Lunar Payload Services program, or CLPS. NASA notified Congress of its intent to discontinue development.
The budgeted cost for building VIPER was $433.5 million, and the estimated cost of building and launching the Griffin lander is $235.6 million, according to a 2022 report from NASA’s Office of the Inspector General.
NASA said it will continue supporting Astrobotic’s Griffin Mission One, with launch set for no earlier than the fall of 2025. Instead of delivering VIPER, the mission would provide a flight demonstration of the lander and its engines. In January, Astrobotic’s Peregrine lander passed up an opportunity to land on the moon due to a problem with its propulsion system.
NASA said other missions could verify the presence of ice in the moon’s south polar region and determine how such resources could be used to further exploration goals.
“We are committed to studying and exploring the moon for the benefit of humanity through the CLPS program,” Nicola Fox, NASA’s associate administrator for science, said today in a news release. “The agency has an array of missions planned to look for ice and other resources on the moon over the next five years. Our path forward will make maximum use of the technology and work that went into VIPER, while preserving critical funds to support our robust lunar portfolio.”
Late this year, for example, Intuitive Machines is due to deliver an ice-mining experiment called PRIME-1 to the south pole under the terms of the CLPS program. PRIME-1 is designed to drill for water ice and study what happens to the H2O when it’s brought up to the surface.
In league with NASA, the CLPS program and a wide array of other partners, the Canadian Space Agency is planning to send an ice-hunting rover to the lunar south polar region by as early as 2026. The Artemis program’s crewed missions will also study the moon’s ice deposits and how they can be used.
NASA said it plans to disassemble VIPER and arrange for the reuse of the rover’s components and scientific instruments for other missions to the moon. But prior to disassembly, the agency said it would consider expressions of interest from commercial and international partners for use of the existing VIPER rover system at no cost to the federal government. Interested parties can email HQ-CLPS-Payload@mail.nasa.gov anytime between July 18 and Aug. 1.
NASA said the VIPER team would conduct an “orderly close-out” through next spring.
Word of VIPER’s demise was met with disappointment in some quarters of the space community. “In the Artemis era, why is lunar science targeted for cancellation?” Laura Seward Forczyk, founder and executive director of the space consulting firm Astralytical, asked in a posting to the X social-media platform.
Phil Metzger, a planetary physicist at the University of Central Florida, said NASA was making a “bad mistake.”
“This was the premier mission to measure lateral and vertical variations of lunar ice in the soil,” Metzger wrote in a posting to X. “It would have been revolutionary. Other missions don’t replace what is lost here.”
Dergelijke tunnels onder het maanoppervlak zouden zomaar eens uitstekende verblijfplaatsen voor mensen kunnen zijn.
NASA en andere ruimtevaartorganisaties hebben al geruime tijd plannen om de maan te koloniseren. Het doel is om er een permanente basis te vestigen waar mensen langdurig kunnen verblijven. Dit biedt de mogelijkheid om essentiële kennis en ervaring op te doen die nodig is voor toekomstige missies naar Mars. Een cruciale vraag is echter: waar moeten toekomstige maankolonisten precies gaan wonen? Bestaan bijvoorbeeld de lang besproken ondergrondse maangrotten echt? Een nieuwe studie biedt nu duidelijkheid.
Lavatunnels Het idee om onder het oppervlak van de maan te gaan wonen, wordt al lange tijd overwogen. Onderzoekers denken daarbij vooral aan lege lavatunnels. Dat heeft namelijk belangrijke voordelen ten opzichte van het bouwen van een basis op het oppervlak. Deze tunnels bieden astronauten bescherming tegen kosmische straling, zonnestraling en micro-meteorieten. En dat is geen overbodige luxe. Kosmische en zonnestraling op het maanoppervlak kunnen namelijk tot wel 150 keer sterker zijn dan wat we op aarde ervaren. Bovendien blijft de temperatuur in deze tunnels stabiel, zonder de dagelijkse variaties die op het oppervlak voorkomen. En ook dat is prettig. Aan de verlichte zijde van de maan kunnen de oppervlaktetemperaturen namelijk oplopen tot een verzengende 127 graden Celsius, terwijl ze aan de onverlichte zijde kunnen dalen tot -173 graden Celsius. Daarnaast liggen deze grotten vaak dichter bij bronnen van waterijs en andere essentiële mineralen die nodig zijn voor langdurig verblijf. Hoewel dit allemaal veelbelovend klinkt, was het tot nu toe nog onduidelijk of dergelijke ondergrondse maangrotten echt bestaan.
Meer over lavatunnels Lavatunnels kunnen op twee verschillende manieren ontstaan. Wanneer lava met een lage viscositeit (stroperigheid) vrij dicht onder het oppervlak stroomt, kan boven de lavastroom een harde – en steeds dikker wordende – korst ontstaan. Die korst vormt als het ware een dak waaronder het gesmolten deel van de lava stroomt. Wanneer de erupties ten einde komen en al het lava is weggestroomd, blijft vlak onder het oppervlak een tunnel achter. Daarnaast kunnen lavatunnels ontstaan wanneer lava zich in bestaande breuken tussen gesteentelagen dwingt. De lava zet uit en creëert een heel netwerk van met elkaar in verbinding staande tunnels die – wanneer de erupties stilvallen – leeg komen te staan.
Tot op heden zijn er al meer dan 200 ‘putten’ ontdekt op het oppervlak van de maan. Deze putten zijn ontstaan door instortingen van onderliggende lavabuizen, wat leidt tot openingen naar ondergrondse holtes. Een prangende vraag is echter of deze putten toegang bieden tot grotten met uitgebreide ondergrondse ruimtes en of ze geschikt zijn om astronauten te huisvesten.
Mare Tranquillitatis Pit In een nieuwe studie hebben onderzoekers besloten om radargegevens van de Lunar Reconnaissance Orbiter te analyseren, specifiek gericht op de Mare Tranquillitatis Pit. Deze put staat bekend als de diepste op de maan, met een diameter van ongeveer 100 meter. “Wat we hebben gedaan, is radargegevens gebruiken om te onderzoeken of deze put een grot verborgen houdt,” vertellen onderzoekers Lorenzo Bruzzone en Leonardo Carrer in gesprek met Scientias.nl. “En wat we ontdekten, was dat de put in de Mare Tranquillitatis daadwerkelijk toegang geeft tot een grot, die we vervolgens in kaart hebben gebracht. Deze grot is bereikbaar vanaf het maanoppervlak. De meest waarschijnlijke verklaring voor onze waarnemingen is een lege lavabuis.”
Ze bestaan Het betekent dat Bruzzone en Carrer nu voor het eerst direct bewijs hebben gevonden van een toegankelijke lavatunnel onder het oppervlak. Een mijlpaal. “Al meer dan 50 jaar zijn maangrotten een mysterie,” vertelt Bruzzone. “Daarom was het opwindend om eindelijk het bestaan van een ondergrondse gang te kunnen bewijzen. Wat interessant is, is dat de gegevens die we in onze studie hebben gebruikt al veertien jaar beschikbaar zijn. Zoals in veel andere gevallen, heeft de ontwikkeling van nieuwe data-analysetechnologieën ook in ons geval geleid tot een nieuwe ontdekking door ‘oude’ gegevens opnieuw te analyseren.”
De maangrot De onderzoekers merkten een toename in radarhelderheid aan de westzijde van de Mare Tranquillitatis Pit op. Door simulaties uit te voeren op basis van de radarbeelden, hebben ze geconcludeerd dat deze observaties kunnen worden verklaard door de aanwezigheid van een holle ruimte die zich uitstrekt vanaf de westkant van de putbodem. De wetenschappers schatten dat deze holle ruimte zich bevindt op een diepte tussen 130 en 170 meter, met een lengte van 30 tot 80 meter en een breedte van ongeveer 45 meter. De grot is mogelijk ook vlak of heeft een helling van maximaal 45 graden.
Maankolonisten De ontdekking van de maangrot geeft hoop voor toekomstige maankolonisten. Zo toont het onderzoek aan dat ondergrondse grotten niet alleen bestaan, maar dat ze ook mogelijk bewoonbaar kunnen zijn. De Mare Tranquillitatis Pit en zijn ondergrondse holte worden bijvoorbeeld gezien als een veelbelovende locatie voor een toekomstige maanbasis. “Op dit moment lopen er verschillende internationale inspanningen van diverse ruimteagentschappen om te onderzoeken of dergelijke grotten geschikt kunnen zijn als schuilplaatsen,” zegt Carrer. “Als de omstandigheden gunstig blijken te zijn, bestaat de mogelijkheid dat ze in de toekomst als schuilplaatsen kunnen worden gebruikt.”
Uitdagingen Dat dit goed wordt onderzocht, is heel belangrijk. Dat komt omdat het leven ondergronds ook zo zijn eigen uitdagingen met zich meebrengt. “Bij het overwegen van het ondergronds huisvesten van astronauten op de maan is veiligheid de belangrijkste prioriteit,” onderstreept Carrer. “Elke mogelijke oplossing heeft zijn eigen voor- en nadelen op het gebied van veiligheid. Het grootste voordeel van grotten is dat ze de belangrijkste structurele onderdelen voor een mogelijke menselijke basis bieden, zonder dat er ingewikkelde bouwwerkzaamheden nodig zijn. Natuurlijk zijn er potentiële risico’s die grondig moeten worden overwogen en geanalyseerd. Denk bijvoorbeeld aan het uitvoeren van grondige structurele analyses om de stabiliteit van de grot te beoordelen, het versterken van de wanden en het plafond van de tunnels, het opzetten van alternatieve leefruimtes zodat astronauten kunnen verhuizen naar een andere veilige zone als een deel van de tunnel beschadigd raakt en het plaatsen van monitorsystemen die bijvoorbeeld aardbevingen kunnen registreren.”
Toekomstige missies De onderzoekers beschouwen hun studie als een startpunt voor verdere verkenning van maangrotten. Ze suggereren dat de gebruikte methode ook van nut kan zijn voor het onderzoeken van andere maanputten en het ontdekken van meerdere ondergrondse gangen. Al hebben we daar wel betere beelden van het maanoppervlak voor nodig. “Helaas zijn de huidige beschikbare gegevens zeer beperkt en bestrijken ze slechts een klein deel van het maanoppervlak,” merkt Bruzzone op. “Bovendien hebben ze niet genoeg detail om kleine grotten te kunnen waarnemen, die juist van groot belang zijn voor het plannen van een maanbasis. Daarom is het van cruciaal belang om nieuwe missies te plannen, bestaande uit satellieten die om de maan draaien en uitgerust zijn met radarinstrumenten. We hebben zowel een radar nodig zoals die we gebruikten voor onze recente ontdekking, om een gedetailleerde kaart te maken van alle maangrotten met voldoende resolutie, als een laagfrequente radarsonde die systematisch het maanoppervlak kan doordringen. Deze sonde moet specifiek ontworpen zijn om holtes en tunnels te detecteren, zelfs op locaties ver van de bekende putten.”
De studie markeert de eerste stap richting het begrijpen van maangrotten als potentiële verblijfplaatsen voor astronauten. Maar het is duidelijk dat er nog veel werk aan de winkel is voordat we kunnen bevestigen dat ze echt ideaal zijn voor langdurige bewoning. Toch zijn ruimtevaartorganisaties optimistisch gestemd. Sinds 2012 voert ESA bijvoorbeeld in samenwerking met enkele Europese universiteiten twee trainingsprogramma’s uit voor astronauten die gericht zijn op de ondergrondse systemen van Lanzarote. Tot dusver hebben al tientallen astronauten trainingen in ‘grotwandelen’ gekregen. Daarnaast hebben al enkele astronauten een geologische veldtraining gevolgd. Dit toont aan dat ESA de lavatunnels op andere hemellichamen zeer geschikt acht als verblijfplaatsen. En wellicht zullen deze ondergrondse systemen inderdaad de eerste nieuwe woonomgevingen voor mensen op een ander hemellichaam worden.
ORLANDO, Fla. — NASA and Boeing completed tests on the ground looking to mirror conditions that led to problems with the CST-100 Starliner that still awaits the go to bring home a pair of astronauts from the International Space Station.
A SpaceX Falcon 9 rocket carrying the company's Crew Dragon spacecraft launched NASA astronauts Robert Behnken and Douglas Hurley to the International Space Station, marking the spacecraft's inaugural crewed flight, on May 30, 2020.
Joel Kowsky/NASA
Butch Wilmore and Suni Williams docked Starliner at the ISS back on June 6 on the Crew Flight Test mission one day after launching from Cape Canaveral Space Force Station atop a United Launch Alliance Atlas V rocket.
What was originally planned to be just an eight-day stay on board the ISS has stretched to more than six weeks because of issues with helium leaks and thruster shutdowns on Starliner’s propulsion module as it approached the station.
While NASA has signed off on Starliner as safe enough to get its two NASA astronauts home in case of an emergency, it’s taking its time to look into as much data as possible about the thrusters and helium leaks before giving them the green light to come home and complete the CFT mission.
After docking, the helium lines were shut down, so no more leaking has occurred, but it will begin again once it undocks. NASA has said the spacecraft, though, has ample helium supply to make the trip home. As far as the reaction control thrusters, which are needed for small position corrections, NASA was able to get four of the five that failed on approach back online, although at lower power levels.
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NASA astronauts Suni Williams and Butch Wilmore say goodbye to friends and family as they leave astronaut crew quarters on their way to the launchpad Wednesday, June 5, 2024.
CRAIG BAILEY/FLORIDA TODAY / USA TODAY NETWORK
NASA's Boeing Crew Flight Test astronauts Butch Wilmore and Suni Williams.
Pic: NASA Johnson
Suni Williams (front left) and Butch Wilmore (front right) as they entered the ISS.
Pic: NASA TV
The Starliner spacecraft on NASA's Boeing Crew Flight Test is pictured docked to the Harmony module's forward port on June 13 as the International Space Station orbited 262 miles above Egypt's Mediterranean coast.
NASA
Suni Williams and Butch Wilmore speak to NASA officials during a live streamed event on Monday, June 10.
NASA
It’s a similar issue seen on the previous Starliner flight, the uncrewed Orbital Flight Test 2 in 2022.
A big issue is the problem propulsion hardware, housed on what’s called the service module, won’t make the flight home along with the crew capsule as it is jettisoned before reentry.
So teams took a surrogate engine for hot fire testing at NASA’s White Sands Test Facility in New Mexico, which was completed last week, mirroring both conditions Starliner experienced on the flight up as well as conditions expected for the return home.
Now teams will evaluate all the test firing data and inspect the engine with work expected to last through this week.
“I am extremely proud of the NASA, Boeing team for their hard work in executing a very complex test series,” said Steve Stich, manager, NASA’s Commercial Crew Program in a press release. “We collected an incredible amount of data on the thruster that could help us better understand what is going on in flight. Next, our team has moved into engine tear downs and inspections which will provide additional insight as we analyze the results and evaluate next steps.”
Before NASA will let Starliner undock, Stich said it has to go through an agency flight test readiness review, and that date has yet to be identified.
Stich previously said that return flight could occur before the end of July, but could also remain on station into mid-August with only the launch of the replacement Crew-9 on a SpaceX Crew Dragon looming next month that would cause a traffic jam.
The CFT mission aims to be the last step before NASA signs off on Boeing to begin the first of six contracted flights to ferry crew to and from the ISS before the station’s retirement as part of NASA’s Commercial Crew Program.
SpaceX is more than four years ahead of Boeing’s efforts as part of the program, and is in the midst of its eighth operational mission to the ISS.
NASA's Curiosity rover discovers a surprise in a Martian rock
NASA's Curiosity rover discovers a surprise in a Martian rock
Story by Science X staff
These yellow crystals were revealed after NASA's Curiosity happened to drive over a rock and crack it open on May 30. Using an instrument on the rover's arm, scientists later determined these crystals are elemental sulfur—and it's the first time this kind of sulfur has been found on the Red Planet.
Scientists were stunned on May 30 when a rock that NASA's Curiosity Mars rover drove over cracked open to reveal something never seen before on the Red Planet: yellow sulfur crystals.
Since October 2023, the rover has been exploring a region of Mars rich with sulfates, a kind of salt that contains sulfur and forms as water evaporates. But where past detections have been of sulfur-based minerals—in other words, a mix of sulfur and other materials—the rock Curiosity recently cracked open is made of elemental (pure) sulfur. It isn't clear what relationship, if any, the elemental sulfur has to other sulfur-based minerals in the area.
While people associate sulfur with the odor from rotten eggs (the result of hydrogen sulfide gas), elemental sulfur is odorless. It forms in only a narrow range of conditions that scientists haven't associated with the history of this location. And Curiosity found a lot of it—an entire field of bright rocks that look similar to the one the rover crushed.
"Finding a field of stones made of pure sulfur is like finding an oasis in the desert," said Curiosity's project scientist, Ashwin Vasavada of NASA's Jet Propulsion Laboratory in Southern California. "It shouldn't be there, so now we have to explain it. Discovering strange and unexpected things is what makes planetary exploration so exciting."
It's one of several discoveries Curiosity has made while off-roading within Gediz Vallis channel, a groove that winds down part of the 3-mile-tall (5-kilometer-tall) Mount Sharp, the base of which the rover has been ascending since 2014. Each layer of the mountain represents a different period of Martian history. Curiosity's mission is to study where and when the planet's ancient terrain could have provided the nutrients needed for microbial life, if any ever formed on Mars.
NASA’s Curiosity captured this close-up image of a rock nicknamed “Snow Lake” on June 8, 2024, the 4,209th Martian day, or sol, of the mission. Nine days earlier, the rover had crushed a similar-looking rock and revealed crystalline textures—and elemental sulfur—inside.
NASA/JPL-Caltech/MSSS NASA’s Curiosity Mars rover captured this view of Gediz Vallis channel on March 31. This area was likely formed by large floods of water and debris that piled jumbles of rocks into mounds within the channel.
Spotted from space years before Curiosity's launch, Gediz Vallis channel is one of the primary reasons the science team wanted to visit this part of Mars. Scientists think that the channel was carved by flows of liquid water and debris that left a ridge of boulders and sediment extending 2 miles down the mountainside below the channel. The goal has been to develop a better understanding of how this landscape changed billions of years ago, and while recent clues have helped, there's still much to learn from the dramatic landscape.
Since Curiosity's arrival at the channel earlier this year, scientists have studied whether ancient floodwaters or landslides built up the large mounds of debris that rise up from the channel's floor here. The latest clues from Curiosity suggest both played a role: Some piles were likely left by violent flows of water and debris, while others appear to be the result of more local landslides.
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Those conclusions are based on rocks found in the debris mounds: Whereas stones carried by water flows become rounded like river rocks, some of the debris mounds are riddled with more angular rocks that may have been deposited by dry avalanches.
Finally, water soaked into all the material that settled here. Chemical reactions caused by the water bleached white "halo" shapes into some of the rocks. Erosion from wind and sand has revealed these halo shapes over time.
"This was not a quiet period on Mars," said Becky Williams, a scientist with the Planetary Science Institute in Tucson, Arizona, and the deputy principal investigator of Curiosity's Mast Camera, or Mastcam. "There was an exciting amount of activity here. We're looking at multiple flows down the channel, including energetic floods and boulder-rich flows."
A hole in 41
All this evidence of water continues to tell a more complex story than the team's early expectations, and they've been eager to take a rock sample from the channel in order to learn more. On June 18, they got their chance.
While the sulfur rocks were too small and brittle to be sampled with the drill, a large rock nicknamed "Mammoth Lakes" was spotted nearby. Rover engineers had to search for a part of the rock that would allow safe drilling and find a parking spot on the loose, sloping surface.
After Curiosity bored its 41st hole using the powerful drill at the end of the rover's 7-foot (2-meter) robotic arm, the six-wheeled scientist trickled the powderized rock into instruments inside its belly for further analysis so that scientists can determine what materials the rock is made of.
Curiosity has since driven away from Mammoth Lakes and is now off to see what other surprises are waiting to be discovered within the channel.
Provided by NASA
This story was originally published on Phys.org. Subscribe to our newsletter for the latest sci-tech news updates.
Study: Biological Amino Acids Could Survive in Near-Surface Ices of Europa and Enceladus
Study: Biological Amino Acids Could Survive in Near-Surface Ices of Europa and Enceladus
Europa and Enceladus are key targets to search for evidence of alien life in our Solar System. However, the surface and shallow subsurface of these airless icy moons are constantly bombarded by ionizing radiation that could degrade chemical biosignatures. Therefore, sampling of icy surfaces in future life detection missions to Europa and Enceladus requires a clear understanding of the necessary ice depth where unaltered organic biomolecules might be present. A team of scientists from NASA and the Pennsylvania State University has conducted experiments by exposing individual biological and abiotic amino acids in ices to gamma radiation to simulate conditions on these icy worlds.
The surface of Europa looms large in this newly-reprocessed color view; image scale is 1.6 km per pixel; north on Europa is at right.
Image credit: NASA / JPL-Caltech / SETI Institute.
“Based on our experiments, the ‘safe’ sampling depth for amino acids on Europa is almost 20 cm (8 inches) at high latitudes of the trailing hemisphere (hemisphere opposite to the direction of Europa’s motion around Jupiter) in the area where the surface hasn’t been disturbed much by meteorite impacts,” said Dr. Alexander Pavlov, a researcher at NASA’s Goddard Space Flight Center.
“Subsurface sampling is not required for the detection of amino acids on Enceladus — these molecules will survive radiolysis (breakdown by radiation) at any location on the Enceladus surface less than a few millimeters (a tenth of an inch) from the surface.”
Dr. Pavlov and his colleagues used amino acids in radiolysis experiments as possible representatives of biomolecules on icy moons.
Amino acids can be created by life or by non-biological chemistry.
However, finding certain kinds of amino acids on Europa or Enceladus would be a potential sign of life because they are used by terrestrial life as a component to build proteins.
Proteins are essential to life as they are used to make enzymes which speed up or regulate chemical reactions and to make structures.
Amino acids and other compounds from subsurface oceans could be brought to the surface by geyser activity or the slow churning motion of the ice crust.
To evaluate the survival of amino acids on these worlds, the researchers mixed samples of amino acids with ice chilled to about minus 196 Celsius (minus 321 Fahrenheit) in sealed, airless vials and bombarded them with gamma-rays, a type of high-energy light, at various doses.
Since the oceans might host microscopic life, they also tested the survival of amino acids in dead bacteria in ice.
Finally, they tested samples of amino acids in ice mixed with silicate dust to consider the potential mixing of material from meteorites or the interior with surface ice.
The experiments provided pivotal data to determine the rates at which amino acids break down, called radiolysis constants.
With these, the scientists used the age of the ice surface and the radiation environment at Europa and Enceladus to calculate the drilling depth and locations where 10% of the amino acids would survive radiolytic destruction.
Although experiments to test the survival of amino acids in ice have been done before, this is the first to use lower radiation doses that don’t completely break apart the amino acids, since just altering or degrading them is enough to make it impossible to determine if they are potential signs of life.
This is also the first experiment using Europa/Enceladus conditions to evaluate the survival of these compounds in microorganisms and the first to test the survival of amino acids mixed with dust.
The scientists found that amino acids degraded faster when mixed with dust but slower when coming from microorganisms.
“Slow rates of amino acid destruction in biological samples under Europa and Enceladus-like surface conditions bolster the case for future life-detection measurements by Europa and Enceladus lander missions,” Dr. Pavlov said.
“Our results indicate that the rates of potential organic biomolecules’ degradation in silica-rich regions on both Europa and Enceladus are higher than in pure ice and, thus, possible future missions to Europa and Enceladus should be cautious in sampling silica-rich locations on both icy moons.”
“A potential explanation for why amino acids survived longer in bacteria involves the ways ionizing radiation changes molecules — directly by breaking their chemical bonds or indirectly by creating reactive compounds nearby which then alter or break down the molecule of interest.”
“It’s possible that bacterial cellular material protected amino acids from the reactive compounds produced by the radiation.”
The team’s paper was published in the journal Astrobiology.
Alexander A. Pavlov et al. 2024. Radiolytic Effects on Biological and Abiotic Amino Acids in Shallow Subsurface Ices on Europa and Enceladus. Astrobiology 24 (7); doi: 10.1089/ast.2023.0120
This article was adapted from an original release by NASA.
Swarming Satellites Could Autonomous Characterize an Asteroid
An asteroid’s size, shape, and rotational speed are clues to its internal properties and potential resources for mining operations. However, of the more than 20,000 near-Earth asteroids currently known, only a tiny fraction have been sufficiently characterized to estimate those three properties accurately. That is essentially a resource constraint – there aren’t enough dedicated telescopes on Earth to keep track of all the asteroids for long enough to characterize them, and deep space resources, such as the Deep Space Network required for communications outside Earth’s orbit, are already overutilized by other missions. Enter the Autonomous Nanosatellite Swarming (ANS) mission concept, developed by Dr. Simone D’Amico and his colleagues at Stanford’s Space Rendezvous Laboratory.
The concept behind ANS is relatively simple. A primary “mothership” spacecraft travels to an asteroid, where it deploys several smaller, autonomous nanosatellites upon arrival. These nanosatellites take up positions surrounding the asteroid and, using relatively inexpensive sensor and communications technology, map the asteroid’s features. After observing for some time, they send data back to the mothership, where an algorithm pieces together information similar to a stereo vision system on Earth and calculates the asteroid’s shape, size, and rotational speed.
There are several deeper layers to unpack in the mission, though. Communication is the first one. In ANS, only the mothership communicates back to Earth using a high-gain antenna. The smaller swarming robots all communicate with each other – partly to estimate distances between the different swarming satellites but also to coordinate observations.
Each nanosatellite utilizes only a few relatively inexpensive pieces of hardware, including a star tracker for overall positioning, short range camera (as compared to more expensive lidar systems typically used in asteroid characterization missions), atomic clocks to synchronize timing, and radio frequency communication modules. These components allow for relatively independent operation of each nanosatellite and lower the burden of communication back with Earth – freeing up those deep space communications resources for other critical work.
But the critical component of ANS isn’t so much the hardware—it’s the software, particularly the control and estimation algorithm. Dr. D’Amico and his team describe a technical tool known as an unscented Kalman filter, which allows them to estimate asteroid shape, size, and rotation based on landmarks noticed by each swarming nanosatellite and run through this algorithm.
To demonstrate the effectiveness of that algorithm, the team tested it using a relatively well-characterized asteroid: 443 Eros. That asteroid had the distinction of being both the first near-Earth object ever found, back in 1898, and the first ever visited by a mission – the NEAR mission 100 years later. The NEAR Shoemaker craft that visited 433 Eros also successfully landed on it, another first for humanity. Even with the comparatively simple sensing technology of a quarter century ago, Eros is still one of the most characterized asteroids in the solar system.
The demonstration results clearly showed that the ANS algorithm does its job well. It can coordinate the positioning of the nanosatellites surrounding the asteroid and coalesce their disparate data sets into a coherent picture of the asteroid they are monitoring. And it can do so remotely, with very minimal input from Earth.
For now, that is how far the algorithm has gotten. Several missions, some of which we’ll cover in the near future, further explore the idea of nanosatellite swarms. But ANS itself hasn’t yet been adopted into a formal mission architecture. One day, though, thousands of satellites might be swarming the tens of thousands of small bodies surrounding our home, leading to the first stages of a genuinely off-Earth economy.
The Most Dangerous Part of a Space Mission is Fire
Astronauts face multiple risks during space flight, such as microgravity and radiation exposure. Microgravity can decrease bone density, and radiation exposure is a carcinogen. However, those are chronic effects.
The biggest risk to astronauts is fire since escape would be difficult on a long mission to Mars or elsewhere beyond Low Earth Orbit. Scientists are researching how fire behaves on spacecraft so astronauts can be protected.
“A fire on board a spacecraft is one of the most dangerous scenarios in space missions,” said Dr. Florian Meyer, head of the Combustion Technology research group at ZARM. “There are hardly any options for getting to a safe place or escaping from a spacecraft. It is therefore crucial to understand the behavior of fires under these special conditions.”
Since 2016, ZARM has been researching how fire behaves and spreads in microgravity conditions like those in the ISS. Those conditions also include an oxygen level similar to Earth’s, forced air circulation, and ambient pressure similar to Earth’s. NASA has been conducting similar experiments, and now we know that fire behaves differently in microgravity than it does on Earth.
Initially, a fire will burn with a smaller flame and take longer to spread. This is to the fire’s advantage since it won’t be noticed as quickly. Fire also burns hotter in microgravity, meaning that some materials that may not be combustible in normal Earth conditions could burn in spacecraft, creating toxic chemicals in the spacecraft’s air.
Spacecraft for Mars missions will have different environments than the ISS. The ambient air pressure will be lower, which provides two benefits: it makes the spacecraft lighter and also allows astronauts to prepare for external missions more quickly. However, the lower ambient pressure introduces another critical change in the spaceship environment. The oxygen content has to be higher to meet the astronauts’ respiration needs.
In these latest tests, the team at ZARM tested fire in these revised conditions.
PMMA stands for polymethyl methacrylate and is usually called acrylic. It’s a common material used in place of glass because it’s light and shatterproof. The ISS doesn’t use it, but it’s being developed for use in future spacecraft. The Orion capsule uses acrylic fused to other materials for windows, and future spacecraft will likely use something similar.
In their experiments, the researchers lit acrylic glass foils on fire and varied three environmental factors: ambient pressure, oxygen content and flow velocity.
The experiments showed that lower ambient pressure dampens fire. However, higher oxygen content has a more powerful effect. The ISS’s oxygen level is 21%, just as it is on Earth. Future spacecraft with lower ambient pressures will have oxygen levels as high as 35%. That translates into a huge increase in the risk astronauts face from fire. The results show that a fire can spread three times faster than it would under Earth conditions.
We all know increased airflow spreads fire faster; that’s why we blow on a small flame to create a larger fire. Increased airflow delivers more oxygen, increasing combustion, so increased airflow in a higher-oxygen atmosphere creates a dangerous situation for astronauts.
“Our results highlight critical factors that need to be considered when developing fire safety protocols for astronautic space missions,” said Dr. Florian Meyer. “By understanding how flames spread under different atmospheric conditions, we can mitigate the risk of fire and improve the safety of the crew.”
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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..
Ik ben geboren op 18/10/1950 en ben nu dus 73 jaar jong.
Mijn hobby's zijn: Ufologie en andere esoterische onderwerpen.
Op deze blog vind je onder artikels, werk van mezelf. Mijn dank gaat ook naar André, Ingrid, Oliver, Paul, Vincent, Georges Filer en MUFON voor de bijdragen voor de verschillende categorieën...
Veel leesplezier en geef je mening over deze blog.