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The International Space Station is pictured from the SpaceX Crew Dragon Endeavour during a fly around.NASA NASA astronaut Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov are headed to the International Space Station for the agency’s SpaceX Crew-9 mission in September. Once on station, these crew members will support scientific investigations that include studies of blood clotting, effects of moisture on plants grown in space, and vision changes in astronauts.
Here are details on some of the work scheduled during the Crew-9 expedition:
Blood cell development in space
Megakaryocytes Orbiting in Outer Space and Near Earth (MeF1) investigates how environmental conditions affect the development and function of megakaryocytes and platelets. Megakaryocytes, large cells found in bone marrow, and platelets, pieces of these cells, play important roles in blood clotting and immune response.
“Understanding the development and function of megakaryocytes and platelets during long-duration spaceflight is crucial to safeguarding the health of astronauts,” said Hansjorg Schwertz, principal investigator, at the University of Utah. “Sending megakaryocyte cell cultures into space offers a unique opportunity to explore their intricate differentiation process. Microgravity also may impact other blood cells, so the insights we gain are likely to enhance our overall comprehension of how spaceflight influences blood cell production.”
Results could provide critical knowledge about the risks of changes in inflammation, immune responses, and clot formation in spaceflight and on the ground.
Scanning electron-microscopy image of human platelets prior to launch to the International Space Station.University of Utah/Megakaryocytes PI Team Patches for NICER
The Neutron Star Interior Composition Explorer (NICER) telescope on the exterior of the space station measures X-rays emitted by neutron stars and other cosmic objects to help answer questions about matter and gravity.
In May 2023, NICER developed a “light leak” that allows sunlight to interfere with daytime measurements. Special patches designed to cover some of the damage will be installed during a future spacewalk, returning the instrument to around-the-clock operation.
“This will be the fourth science observatory and first X-ray telescope in orbit to be repaired by astronauts,” said principal investigator Keith Gendreau at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “In just a year, we diagnosed the problem, designed and tested a solution, and delivered it for launch. The space station team — from managers and safety experts to engineers and astronauts — helped us make it happen. We’re looking forward to getting back to normal science operations.”
This view shows NICER’s 56 X-ray concentrators. Astronauts plan to cover some of them with special patches on a future spacewalk. NASA Vitamins for vision
Some astronauts experience vision changes, a condition called Spaceflight-Associated Neuro-ocular Syndrome. The B Complex investigation tests whether a daily B vitamin supplement can prevent or mitigate this problem and assesses how genetics may influence individual response.
“We still do not know exactly what causes this syndrome, and not everyone gets it,” said Sara Zwart, principal investigator, at the University of Texas Medical Branch, Houston. “It is likely many factors, and biological variations that make some astronauts more susceptible than others.”
One such variation could be related to a metabolic pathway that requires B vitamins to function properly. Inefficiencies in this pathway can affect the inner lining of blood vessels, resulting in leaks that may contribute to vision changes. Providing B vitamins known to affect blood vessel function positively could minimize issues in genetically at-risk astronauts.
“The concept of this study is based on 13 years of flight and ground research,” Zwart said. “We are excited to finally flight test a low-risk countermeasure that could mitigate the risk on future missions, including those to Mars.”
NASA astronaut Mark Vande Hei conducts a vision exam on the International Space StationNASA Watering the space garden
As people travel farther from Earth for longer, growing food becomes increasingly important. Scientists conducted many plant growth experiments on the space station using its Veggie hardware, including Veg-01B, which demonstrated that ‘Outredgeous’ red romaine lettuce is suitable for crop production in space.
Plant Habitat-07 uses this lettuce to examine how moisture conditions affect the nutritional quality and microbial safety of plants. The Advanced Plant Habitat controls humidity, temperature, air, light, and soil moisture, creating the precise conditions needed for the experiment.
Using a plant known to grow well in space removes a challenging variable from the equation, explained Chad Vanden Bosch, principal investigator at Redwire, and this lettuce also has been proven to be safe to consume when grown in space.
“For crews building a base on the Moon or Mars, tending to plants may be low on their list of responsibilities, so plant growth systems need to be automated,” Bosch said. “Such systems may not always provide the perfect growing conditions, though, so we need to know if plants grown in suboptimal conditions are safe to consume.”
This preflight image shows lettuce grown under control (left) and flood (right) moisture treatments. Plant Habitat-07 team Melissa Gaskill
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5 Min Read NASA’s Webb Peers into the Extreme Outer Galaxy
This image shows a portion of the star-forming region, known as Digel Cloud 2S (full image below). Credits:
NASA, ESA, CSA, STScI, M. Ressler (JPL) Astronomers have directed NASA’s James Webb Space Telescope to examine the outskirts of our Milky Way galaxy. Scientists call this region the Extreme Outer Galaxy due to its location more than 58,000 light-years away from the Galactic Center. (For comparison, Earth is approximately 26,000 light-years from the center.)
A team of scientists used Webb’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument) to image select regions within two molecular clouds known as Digel Clouds 1 and 2. With its high degree of sensitivity and sharp resolution, the Webb data resolved these areas, which are hosts to star clusters undergoing bursts of star formation, in unprecedented detail. Details of this data include components of the clusters such as very young (Class 0) protostars, outflows and jets, and distinctive nebular structures.
These Webb observations, which came from telescope time allocated to Mike Ressler of NASA’s Jet Propulsion Laboratory in Southern California, are enabling scientists to study star formation in the outer Milky Way in the same depth of detail as observations of star formation in our own solar neighborhood.
“In the past, we knew about these star forming regions but were not able to delve into their properties,” said Natsuko Izumi of Gifu University and the National Astronomical Observatory of Japan, lead author of the study. “The Webb data builds upon what we have incrementally gathered over the years from prior observations with different telescopes and observatories. We can get very powerful and impressive images of these clouds with Webb. In the case of Digel Cloud 2, I did not expect to see such active star formation and spectacular jets.”
Image A: Extreme Outer Galaxy (NIRCam and MIRI)
Scientists used NASA’s James Webb Space Telescope to examine select star-forming areas in the Extreme Outer Galaxy in near- and mid-infrared light. Within this star-forming region, known as Digel Cloud 2S, the telescope observed young, newly formed stars and their extended jets of material. This Webb image also shows a dense sea of background galaxies and red nebulous structures within the region. In this image, colors were assigned to different filters from Webb’s MIRI and NIRCam: red (F1280W, F770W, F444W), green (F356W, F200W), and blue (F150W; F115W). NASA, ESA, CSA, STScI, M. Ressler (JPL) Stars in the Making
Although the Digel Clouds are within our galaxy, they are relatively poor in elements heavier than hydrogen and helium. This composition makes them similar to dwarf galaxies and our own Milky Way in its early history. Therefore, the team took the opportunity to use Webb to capture the activity occurring in four clusters of young stars within Digel Clouds 1 and 2: 1A, 1B, 2N, and 2S.
For Cloud 2S, Webb captured the main cluster containing young, newly formed stars. This dense area is quite active as several stars are emitting extended jets of material along their poles. Additionally, while scientists previously suspected a sub-cluster might be present within the cloud, Webb’s imaging capabilities confirmed its existence for the first time.
“We know from studying other nearby star-forming regions that as stars form during their early life phase, they start emitting jets of material at their poles,” said Ressler, second author of the study and principal investigator of the observing program. “What was fascinating and astounding to me from the Webb data is that there are multiple jets shooting out in all different directions from this cluster of stars. It’s a little bit like a firecracker, where you see things shooting this way and that.”
The Saga of Stars
The Webb imagery skims the surface of the Extreme Outer Galaxy and the Digel Clouds, and is just a starting point for the team. They intend to revisit this outpost in the Milky Way to find answers to a variety of current mysteries, including the relative abundance of stars of various masses within Extreme Outer Galaxy star clusters. This measurement can help astronomers understand how a particular environment can influence different types of stars during their formation.
“I’m interested in continuing to study how star formation is occurring in these regions. By combining data from different observatories and telescopes, we can examine each stage in the evolution process,” said Izumi. “We also plan to investigate circumstellar disks within the Extreme Outer Galaxy. We still don’t know why their lifetimes are shorter than in star-forming regions much closer to us. And of course, I’d like to understand the kinematics of the jets we detected in Cloud 2S.”
Though the story of star formation is complex and some chapters are still shrouded in mystery, Webb is gathering clues and helping astronomers unravel this intricate tale.
These findings have been published in the Astronomical Journal.
The observations were taken as part of Guaranteed Time Observation program 1237.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
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Space Telescope Science Institute, Baltimore, Md.
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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
This bar graph shows GISTEMP summer global temperature anomalies for 2023 (shown in yellow) and 2024 (shown in red). June through August is considered meteorological summer in the Northern Hemisphere. The white lines indicate the range of estimated temperatures. The warmer-than-usual summers continue a long-term trend of warming, driven primarily by human-caused greenhouse gas emissions. NASA/Peter Jacobs The agency also shared new state-of-the-art datasets that allow scientists to track Earth’s temperature for any month and region going back to 1880 with greater certainty.
August 2024 set a new monthly temperature record, capping Earth’s hottest summer since global records began in 1880, according to scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. The announcement comes as a new analysis upholds confidence in the agency’s nearly 145-year-old temperature record.
June, July, and August 2024 combined were about 0.2 degrees Fahrenheit (about 0.1 degrees Celsius) warmer globally than any other summer in NASA’s record — narrowly topping the record just set in 2023. Summer of 2024 was 2.25 F (1.25 C) warmer than the average summer between 1951 and 1980, and August alone was 2.34 F (1.3 C) warmer than average. June through August is considered meteorological summer in the Northern Hemisphere.
“Data from multiple record-keepers show that the warming of the past two years may be neck and neck, but it is well above anything seen in years prior, including strong El Niño years,” said Gavin Schmidt, director of GISS. “This is a clear indication of the ongoing human-driven warming of the climate.”
NASA assembles its temperature record, known as the GISS Surface Temperature Analysis (GISTEMP), from surface air temperature data acquired by tens of thousands of meteorological stations, as well as sea surface temperatures from ship- and buoy-based instruments. It also includes measurements from Antarctica. Analytical methods consider the varied spacing of temperature stations around the globe and urban heating effects that could skew the calculations.
The GISTEMP analysis calculates temperature anomalies rather than absolute temperature. A temperature anomaly shows how far the temperature has departed from the 1951 to 1980 base average.
New assessment of temperature record
The summer record comes as new research from scientists at the Colorado School of Mines, National Science Foundation, the National Atmospheric and Oceanic Administration (NOAA), and NASA further increases confidence in the agency’s global and regional temperature data.
“Our goal was to actually quantify how good of a temperature estimate we’re making for any given time or place,” said lead author Nathan Lenssen, a professor at the Colorado School of Mines and project scientist at the National Center for Atmospheric Research (NCAR).
This visualization of GISTEMP monthly temperatures with the seasonal cycle derived from the Global Modeling and Assimilation Office’s MERRA-2 model compares 2023 (in red) and 2024 (in purple), with a transparent ribbon around each indicating the confidence intervals from the new GISTEMP uncertainty calculation. The white lines show monthly temperatures from the years 1961 to 2022. June, July, and August 2024 combined were about 0.2 degrees Fahrenheit (about 0.1 degrees Celsius) warmer globally than any other summer in NASA’s record — narrowly topping the record set in 2023.NASA/Peter Jacobs/Katy Mersmann The researchers affirmed that GISTEMP is correctly capturing rising surface temperatures on our planet and that Earth’s global temperature increase since the late 19th century — summer 2024 was about 2.7 F (1.51 C) warmer than the late 1800s — cannot be explained by any uncertainty or error in the data.
The authors built on previous work showing that NASA’s estimate of global mean temperature rise is likely accurate to within a tenth of a degree Fahrenheit in recent decades. For their latest analysis, Lenssen and colleagues examined the data for individual regions and for every month going back to 1880.
Estimating the unknown
Lenssen and colleagues provided a rigorous accounting of statistical uncertainty within the GISTEMP record. Uncertainty in science is important to understand because we cannot take measurements everywhere. Knowing the strengths and limitations of observations helps scientists assess if they’re really seeing a shift or change in the world.
The study confirmed that one of the most significant sources of uncertainty in the GISTEMP record is localized changes around meteorological stations. For example, a previously rural station may report higher temperatures as asphalt and other heat-trapping urban surfaces develop around it. Spatial gaps between stations also contribute some uncertainty in the record. GISTEMP accounts for these gaps using estimates from the closest stations.
Previously, scientists using GISTEMP estimated historical temperatures using what’s known in statistics as a confidence interval — a range of values around a measurement, often read as a specific temperature plus or minus a few fractions of degrees. The new approach uses a method known as a statistical ensemble: a spread of the 200 most probable values. While a confidence interval represents a level of certainty around a single data point, an ensemble tries to capture the whole range of possibilities.
The distinction between the two methods is meaningful to scientists tracking how temperatures have changed, especially where there are spatial gaps. For example: Say GISTEMP contains thermometer readings from Denver in July 1900, and a researcher needs to estimate what conditions were 100 miles away. Instead of reporting the Denver temperature plus or minus a few degrees, the researcher can analyze scores of equally probable values for southern Colorado and communicate the uncertainty in their results.
What does this mean for recent heat rankings?
Every year, NASA scientists use GISTEMP to provide an annual global temperature update, with 2023 ranking as the hottest year to date.
Other researchers affirmed this finding, including NOAA and the European Union’s Copernicus Climate Change Service. These institutions employ different, independent methods to assess Earth’s temperature. Copernicus, for instance, uses an advanced computer-generated approach known as reanalysis.
The records remain in broad agreement but can differ in some specific findings. Copernicus determined that July 2023 was Earth’s hottest month on record, for example, while NASA found July 2024 had a narrow edge. The new ensemble analysis has now shown that the difference between the two months is smaller than the uncertainties in the data. In other words, they are effectively tied for hottest. Within the larger historical record the new ensemble estimates for summer 2024 were likely 2.52-2.86 degrees F (1.40-1.59 degrees C) warmer than the late 19th century, while 2023 was likely 2.34-2.68 degrees F (1.30-1.49 degrees C) warmer.
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5 Min Read 9 Phenomena NASA Astronauts Will Encounter at Moon’s South Pole
An artist’s rendering of an Artemis astronaut working on the Moon’s surface. Credits:
NASA NASA’s Artemis campaign will send the first woman and the first person of color to the Moon’s south polar region, marking humanity’s first return to the lunar surface in more than 50 years.
Here are some out-of-this-world phenomena Artemis astronauts will experience:
1. A Hovering Sun and Giant Shadows
This visualization shows the motions of Earth and the Sun as viewed from the South Pole of the Moon.
NASA’s Goddard Space Flight Center Near the Moon’s South Pole, astronauts will see dramatic shadows that are 25 to 50 times longer than the objects casting them. Why? Because the Sun strikes the surface there at a low angle, hanging just a few degrees above the horizon. As a result, astronauts won’t see the Sun rise and set. Instead, they’ll watch it hover near the horizon as it moves horizontally across the sky.
2. Sticky, Razor-Sharp Dust …
This dust particle came from a lunar regolith sample brought to Earth in 1969 by Apollo 11 astronauts. The particle is about 25 microns across, less than the width of an average human hair. The image was taken with a scanning electron microscope. The lunar dust, called regolith, that coats the Moon’s surface looks fine and soft like baking powder. But looks can be deceiving. Lunar regolith is formed when meteoroids hit the Moon’s surface, melting and shattering rocks into tiny, sharp pieces. The Moon doesn’t have moving water or wind to smooth out the regolith grains, so they stay sharp and scratchy, posing a risk to astronauts and their equipment.
3. … That’s Charged with Static Electricity
Astronaut Eugene Cernan, commander of Apollo 17, inside the lunar module on the Moon after his second moonwalk of the mission in 1972. His spacesuit and face are covered in lunar dust. Because the Moon has no atmosphere to speak of, its surface is exposed to plasma and radiation from the Sun. As a result, static electricity builds up on the surface, as it does when you shuffle your feet against a carpeted floor. When you then touch something, you transfer that charge via a small shock. On the Moon, this transfer can short-circuit electronics. Moon dust also can make its way into astronaut living quarters, as the static electricity causes it to easily stick to spacesuits. NASA has developed methods to keep the dust at bay using resistant textiles, filters, and a shield that employs an electric field to remove dust from surfaces.
4. A New Sense of Lightness
In 1972, Apollo 16 astronaut Charles Duke hammered a core tube into the Moon’s surface until it met a rock and wouldn’t go any farther. Then the hammer flew from his hand. He made four attempts to pick it up by bending down and leaning to reach for it. He gave up and returned to the rover to get tongs to finally pick up the hammer successfully.
NASA’s Johnson Space Center Artemis moonwalkers will have a bounce to their step as they traverse the lunar surface. This is because gravity won’t pull them down as forcefully as it does on Earth. The Moon is only a quarter of Earth’s size, with six times less gravity. Simple activities, like swinging a rock hammer to chip off samples, will feel different. While a hammer will feel lighter to hold, its inertia won’t change, leading to a strange sensation for astronauts. Lower gravity has perks, too. Astronauts won’t be weighed down by their hefty spacesuits as much as they would be on Earth. Plus, bouncing on the Moon is just plain fun.
5. A Waxing Crescent … Earth?
This animated image features a person holding a stick with a sphere on top that represents the Moon. The person is demonstrating an activity that helps people learn about the phases of the Moon by acting them out. NASA’s Jet Propulsion Laboratory When Artemis astronauts look at the sky from the Moon, they’ll see their home planet shining back at them. Just like Earthlings see different phases of the Moon throughout a month, astronauts will see an ever-shifting Earth. Earth phases occur opposite to Moon phases: When Earth experiences a new Moon, a full Earth is visible from the Moon.
6. An Itty-Bitty Horizon
A view from the Apollo 11 spacecraft in July 1969 shows Earth rising above the Moon’s horizon. NASA Because the Moon is smaller than Earth, its horizon will look shorter and closer. To someone standing on a level Earth surface, the horizon is 3 miles away, but to astronauts on the Moon, it’ll be only 1.5 miles away, making their surroundings seem confined.
7. Out-of-This-World Temperatures
This graphic shows maximum summer and winter temperatures near the lunar South Pole. Purple, blue, and green identify cold regions, while yellow to red signify warmer ones. The graphic incorporates 10 years of data from NASA’s LRO (Lunar Reconnaissance Orbiter), which has been orbiting the Moon since 2009.
NASA/LRO Diviner Seasonal Polar Data Because sunlight at the Moon’s South Pole skims the surface horizontally, it brushes crater rims, but doesn’t always reach their floors. Some deep craters haven’t seen the light of day for billions of years, so temperatures there can dip to minus 334 F. That’s nearly three times colder than the lowest temperature recorded in Antarctica. At the other extreme, areas in direct sunlight, such as crater rims, can reach temperatures of 130 F.
8. An Inky-Black Sky
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An animated view of Earth emerging below the horizon as seen from the Moon’s South Pole. This visual was created using a digital elevation map from LRO’s laser altimeter, LOLA. NASA’s Scientific Visualization Studio The Moon, unlike Earth, doesn’t have a thick atmosphere to scatter blue light, so the daytime sky is black. Astronauts will see a stark contrast between the dark sky and the bright ground.
9. A Rugged Terrain
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An overhead view of the Moon, beginning with a natural color from a distance and changing to color-coded elevation as the camera comes closer. The visual captures the rugged terrain of the lunar South Pole area. It includes a color key and animated scale bar. This visual was created using a digital elevation map from NASA LRO’s laser altimeter, LOLA. NASA’s Scientific Visualization Studio Artemis moonwalkers will find a rugged landscape that takes skill to traverse. The Moon has mountains, valleys, and canyons, but its most notable feature for astronauts on the surface may be its millions of craters. Near the South Pole, gaping craters and long shadows will make it difficult for astronauts to navigate. But, with training and special gear, astronauts will be prepared to meet the challenge.
By Avery Truman
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Preparations for Next Moonwalk Simulations Underway (and Underwater)
Tests on Earth appear to confirm how the Red Planet’s spider-shaped geologic formations are carved by carbon dioxide.
Spider-shaped features called araneiform terrain are found in the southern hemisphere of Mars, carved into the landscape by carbon dioxide gas. This 2009 image taken by NASA’s Mars Reconnaissance Orbiter shows several of these distinctive formations within an area three-quarters of a mile (1.2 kilometers) wide. NASA/JPL-Caltech/University of Arizona Dark splotches seen in this example of araneiform terrain captured by NASA’s Mars Reconnaissance Orbiter in 2018 are believed to be soil ejected from the surface by carbon dioxide gas plumes. A set of experiments at JPL has sought to re-create these spider-like formations in a lab. NASA/JPL-Caltech/University of Arizona Since discovering them in 2003 via images from orbiters, scientists have marveled at spider-like shapes sprawled across the southern hemisphere of Mars. No one is entirely sure how these geologic features are created. Each branched formation can stretch more than a half-mile (1 kilometer) from end to end and include hundreds of spindly “legs.” Called araneiform terrain, these features are often found in clusters, giving the surface a wrinkled appearance.
The leading theory is that the spiders are created by processes involving carbon dioxide ice, which doesn’t occur naturally on Earth. Thanks to experiments detailed in a new paper published in The Planetary Science Journal, scientists have, for the first time, re-created those formation processes in simulated Martian temperatures and air pressure.
Here’s a look inside of JPL’s DUSTIE, a wine barrel-size chamber used to simulate the temperatures and air pressure of other planets – in this case, the carbon dioxide ice found on Mars’ south pole. Experiments conducted in the chamber confirmed how Martian formations known as “spiders” are created.NASA/JPL-Caltech “The spiders are strange, beautiful geologic features in their own right,” said Lauren Mc Keown of NASA’s Jet Propulsion Laboratory in Southern California. “These experiments will help tune our models for how they form.”
The study confirms several formation processes described by what’s called the Kieffer model: Sunlight heats the soil when it shines through transparent slabs of carbon dioxide ice that built up on the Martian surface each winter. Being darker than the ice above it, the soil absorbs the heat and causes the ice closest to it to turn directly into carbon dioxide gas — without turning to liquid first — in a process called sublimation (the same process that sends clouds of “smoke” billowing up from dry ice). As the gas builds in pressure, the Martian ice cracks, allowing the gas to escape. As it seeps upward, the gas takes with it a stream of dark dust and sand from the soil that lands on the surface of the ice.
When winter turns to spring and the remaining ice sublimates, according to the theory, the spiderlike scars from those small eruptions are what’s left behind.
These formations similar to the Red Planet’s “spiders” appeared within Martian soil simulant during experiments in JPL’s DUSTIE chamber. Carbon dioxide ice frozen within the simulant was warmed by a heater below, turning it back into gas that eventually cracked through the frozen top layer and formed a plume.NASA/JPL-Caltech Re-Creating Mars in the Lab
For Mc Keown and her co-authors, the hardest part of conducting these experiments was re-creating conditions found on the Martian polar surface: extremely low air pressure and temperatures as low as minus 301 degrees Fahrenheit (minus 185 degrees Celsius). To do that, Mc Keown used a liquid-nitrogen-cooled test chamber at JPL, the Dirty Under-vacuum Simulation Testbed for Icy Environments, or DUSTIE.
“I love DUSTIE. It’s historic,” Mc Keown said, noting that the wine barrel-size chamber was used to test a prototype of a rasping tool designed for NASA’s Mars Phoenix lander. The tool was used to break water ice, which the spacecraft scooped up and analyzed near the planet’s north pole.
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This video shows Martian soil simulant erupting in a plume during a JPL lab experiment that was designed to replicate the process believed to form Martian features called “spiders.” When a researcher who had tried for years to re-create these conditions spotted this plume, she was ecstatic. NASA/JPL-Caltech For this experiment, the researchers chilled Martian soil simulant in a container submerged within a liquid nitrogen bath. They placed it in the DUSTIE chamber, where the air pressure was reduced to be similar to that of Mars’ southern hemisphere. Carbon dioxide gas then flowed into the chamber and condensed from gas to ice over the course of three to five hours. It took many tries before Mc Keown found just the right conditions for the ice to become thick and translucent enough for the experiments to work.
Once they got ice with the right properties, they placed a heater inside the chamber below the simulant to warm it up and crack the ice. Mc Keown was ecstatic when she finally saw a plume of carbon dioxide gas erupting from within the powdery simulant.
“It was late on a Friday evening and the lab manager burst in after hearing me shrieking,” said Mc Keown, who had been working to make a plume like this for five years. “She thought there had been an accident.”
The dark plumes opened holes in the simulant as they streamed out, spewing simulant for as long as 10 minutes before all the pressurized gas was expelled.
The experiments included a surprise that wasn’t reflected in the Kieffer model: Ice formed between the grains of the simulant, then cracked it open. This alternative process might explain why spiders have a more “cracked” appearance. Whether this happens or not seems dependent on the size of soil grains and how embedded water ice is underground.
“It’s one of those details that show that nature is a little messier than the textbook image,” said Serina Diniega of JPL, a co-author of the paper.
What’s Next for Plume Testing
Now that the conditions have been found for plumes to form, the next step is to try the same experiments with simulated sunlight from above, rather than using a heater below. That could help scientists narrow down the range of conditions under which the plumes and ejection of soil might occur.
There are still many questions about the spiders that can’t be answered in a lab. Why have they formed in some places on Mars but not others? Since they appear to result from seasonal changes that are still occurring, why don’t they seem to be growing in number or size over time? It’s possible that they’re left over from long ago, when the climate was different on Mars— and could therefore provide a unique window into the planet’s past.
For the time being, lab experiments will be as close to the spiders as scientists can get. Both the Curiosity and Perseverance rovers are exploring the Red Planet far from the southern hemisphere, which is where these formations appear (and where no spacecraft has ever landed). The Phoenix mission, which landed in the northern hemisphere, lasted only a few months before succumbing to the intense polar cold and limited sunlight.
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