Members Can Post Anonymously On This Site
Turning astronaut urine into fuel on Mars
-
Similar Topics
-
By NASA
NASA’s Dawn spacecraft captured this image of Vesta as it left the giant asteroid’s orbit in 2012. The framing camera was looking down at the north pole, which is in the middle of the image.NASA/JPL-Caltech/UCLA/MPS/DLR/IDA Known as flow formations, these channels could be etched on bodies that would seem inhospitable to liquid because they are exposed to the extreme vacuum conditions of space.
Pocked with craters, the surfaces of many celestial bodies in our solar system provide clear evidence of a 4.6-billion-year battering by meteoroids and other space debris. But on some worlds, including the giant asteroid Vesta that NASA’s Dawn mission explored, the surfaces also contain deep channels, or gullies, whose origins are not fully understood.
A prime hypothesis holds that they formed from dry debris flows driven by geophysical processes, such as meteoroid impacts, and changes in temperature due to Sun exposure. A recent NASA-funded study, however, provides some evidence that impacts on Vesta may have triggered a less-obvious geologic process: sudden and brief flows of water that carved gullies and deposited fans of sediment. By using lab equipment to mimic conditions on Vesta, the study, which appeared in Planetary Science Journal, detailed for the first time what the liquid could be made of and how long it would flow before freezing.
Although the existence of frozen brine deposits on Vesta is unconfirmed, scientists have previously hypothesized that meteoroid impacts could have exposed and melted ice that lay under the surface of worlds like Vesta. In that scenario, flows resulting from this process could have etched gullies and other surface features that resemble those on Earth.
To explore potential explanations for deep channels, or gullies, seen on Vesta, scientists used JPL’s Dirty Under-vacuum Simulation Testbed for Icy Environments, or DUSTIE, to simulate conditions on the giant asteroid that would occur after meteoroids strike the surface.NASA/JPL-Caltech But how could airless worlds — celestial bodies without atmospheres and exposed to the intense vacuum of space — host liquids on the surface long enough for them to flow? Such a process would run contrary to the understanding that liquids quickly destabilize in a vacuum, changing to a gas when the pressure drops.
“Not only do impacts trigger a flow of liquid on the surface, the liquids are active long enough to create specific surface features,” said project leader and planetary scientist Jennifer Scully of NASA’s Jet Propulsion Laboratory in Southern California, where the experiments were conducted. “But for how long? Most liquids become unstable quickly on these airless bodies, where the vacuum of space is unyielding.”
The critical component turns out to be sodium chloride — table salt. The experiments found that in conditions like those on Vesta, pure water froze almost instantly, while briny liquids stayed fluid for at least an hour. “That’s long enough to form the flow-associated features identified on Vesta, which were estimated to require up to a half-hour,” said lead author Michael J. Poston of the Southwest Research Institute in San Antonio.
Launched in 2007, the Dawn spacecraft traveled to the main asteroid belt between Mars and Jupiter to orbit Vesta for 14 months and Ceres for almost four years. Before ending in 2018, the mission uncovered evidence that Ceres had been home to a subsurface reservoir of brine and may still be transferring brines from its interior to the surface. The recent research offers insights into processes on Ceres but focuses on Vesta, where ice and salts may produce briny liquid when heated by an impact, scientists said.
Re-creating Vesta
To re-create Vesta-like conditions that would occur after a meteoroid impact, the scientists relied on a test chamber at JPL called the Dirty Under-vacuum Simulation Testbed for Icy Environments, or DUSTIE. By rapidly reducing the air pressure surrounding samples of liquid, they mimicked the environment around fluid that comes to the surface. Exposed to vacuum conditions, pure water froze instantly. But salty fluids hung around longer, continuing to flow before freezing.
The brines they experimented with were a little over an inch (a few centimeters) deep; scientists concluded the flows on Vesta that are yards to tens of yards deep would take even longer to refreeze.
The researchers were also able to re-create the “lids” of frozen material thought to form on brines. Essentially a frozen top layer, the lids stabilize the liquid beneath them, protecting it from being exposed to the vacuum of space — or, in this case the vacuum of the DUSTIE chamber — and helping the liquid flow longer before freezing again.
This phenomenon is similar to how on Earth lava flows farther in lava tubes than when exposed to cool surface temperatures. It also matches up with modeling research conducted around potential mud volcanoes on Mars and volcanoes that may have spewed icy material from volcanoes on Jupiter’s moon Europa.
“Our results contribute to a growing body of work that uses lab experiments to understand how long liquids last on a variety of worlds,” Scully said.
Find more information about NASA’s Dawn mission here:
https://science.nasa.gov/mission/dawn/
News Media Contacts
Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.
818-287-4115
gretchen.p.mccartney@jpl.nasa.gov
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
2024-178
Share
Details
Last Updated Dec 20, 2024 Related Terms
Dawn Asteroids Ceres Jet Propulsion Laboratory Vesta Explore More
5 min read Avalanches, Icy Explosions, and Dunes: NASA Is Tracking New Year on Mars
Article 1 hour ago 5 min read Cutting-Edge Satellite Tracks Lake Water Levels in Ohio River Basin
Article 3 days ago 5 min read NASA Mars Orbiter Spots Retired InSight Lander to Study Dust Movement
Article 4 days ago Keep Exploring Discover More Topics From NASA
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
It’s a new year on Mars, and while New Year’s means winter in Earth’s northern hemisphere, it’s the start of spring in the same region of the Red Planet. And that means ice is thawing, leading to all sorts of interesting things. JPL research scientist Serina Diniega explains. NASA/JPL-Caltech Instead of a winter wonderland, the Red Planet’s northern hemisphere goes through an active — even explosive — spring thaw.
While New Year’s Eve is around the corner here on Earth, Mars scientists are ahead of the game: The Red Planet completed a trip around the Sun on Nov. 12, 2024, prompting a few researchers to raise a toast.
But the Martian year, which is 687 Earth days, ends in a very different way in the planet’s northern hemisphere than it does in Earth’s northern hemisphere: While winter’s kicking in here, spring is starting there. That means temperatures are rising and ice is thinning, leading to frost avalanches crashing down cliffsides, carbon dioxide gas exploding from the ground, and powerful winds helping reshape the north pole.
“Springtime on Earth has lots of trickling as water ice gradually melts. But on Mars, everything happens with a bang,” said Serina Diniega, who studies planetary surfaces at NASA’s Jet Propulsion Laboratory in Southern California.
Mars’ wispy atmosphere doesn’t allow liquids to pool on the surface, like on Earth. Instead of melting, ice sublimates, turning directly into a gas. The sudden transition in spring means a lot of violent changes as both water ice and carbon dioxide ice — dry ice, which is much more plentiful on Mars than frozen water — weaken and break.
“You get lots of cracks and explosions instead of melting,” Diniega said. “I imagine it gets really noisy.”
Using the cameras and other sensors aboard NASA’s Mars Reconnaissance Orbiter (MRO), which launched in 2005, scientists study all this activity to improve their understanding of the forces shaping the dynamic Martian surface. Here’s some of what they track.
Frost Avalanches
In 2015, MRO’s High-Resolution Imaging Science Experiment (HiRISE) camera captured a 66-foot-wide (20-meter-wide) chunk of carbon dioxide frost in freefall. Chance observations like this are reminders of just how different Mars is from Earth, Diniega said, especially in springtime, when these surface changes are most noticeable.
Martian spring involves lots of cracking ice, which led to this 66-foot-wide (20-meter-wide) chunk of carbon dioxide frost captured in freefall by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter in 2015NASA/JPL-Caltech/University of Arizona “We’re lucky we’ve had a spacecraft like MRO observing Mars for as long as it has,” Diniega said. “Watching for almost 20 years has let us catch dramatic moments like these avalanches.”
Gas Geysers
Diniega has relied on HiRISE to study another quirk of Martian springtime: gas geysers that blast out of the surface, throwing out dark fans of sand and dust. These explosive jets form due to energetic sublimation of carbon dioxide ice. As sunlight shines through the ice, its bottom layers turn to gas, building pressure until it bursts into the air, creating those dark fans of material.
As light shines through carbon dioxide ice on Mars, it heats up its bottom layers, which, rather than melting into a liquid, turn into gas. The buildup gas eventually results in explosive geysers that toss dark fans of debris on to the surface.light shines through carbon dioxide ice on Mars But to see the best examples of the newest fans, researchers will have to wait until December 2025, when spring starts in the southern hemisphere. There, the fans are bigger and more clearly defined.
Spiders
Another difference between ice-related action in the two hemispheres: Once all the ice around some northern geysers has sublimated in summer, what’s left behind in the dirt are scour marks that, from space, look like giant spider legs. Researchers recently re-created this process in a JPL lab.
Sometimes, after carbon dioxide geysers have erupted from ice-covered areas on Mars, they leave scour marks on the surface. When the ice is all gone by summer, these long scour marks look like the legs of giant spiders.NASA/JPL-Caltech/University of Arizona Powerful Winds
For Isaac Smith of Toronto’s York University, one of the most fascinating subjects in springtime is the Texas-size ice cap at Mars’ north pole. Etched into the icy dome are swirling troughs, revealing traces of the red surface below. The effect is like a swirl of milk in a café latte.
“These things are enormous,” Smith said, noting that some are a long as California. “You can find similar troughs in Antarctica but nothing at this scale.”
As temperatures rise, powerful winds kick up that carve deep troughs into the ice cap of Mars’ north pole. Some of these troughs are as long as California, and give the Martian north pole its trademark swirls. This image was captured by NASA’s now-inactive Mars Global Surveyor.NASA/JPL-Caltech/MSSS Fast, warm wind has carved the spiral shapes over eons, and the troughs act as channels for springtime wind gusts that become more powerful as ice at the north pole starts to thaw. Just like the Santa Ana winds in Southern California or the Chinook winds in the Rocky Mountains, these gusts pick up speed and temperature as they ride down the troughs — what’s called an adiabatic process.
Wandering Dunes
The winds that carve the north pole’s troughs also reshape Mars’ sand dunes, causing sand to pile up on one side while removing sand from the other side. Over time, the process causes dunes to migrate, just as it does with dunes on Earth.
This past September, Smith coauthored a paper detailing how carbon dioxide frost settles on top of polar sand dunes during winter, freezing them in place. When the frost all thaws away in the spring, the dunes begin migrating again.
Surrounded by frost, these Martian dunes in Mars’ northern hemisphere were captured from above by NASA’s Mars Reconnaissance Orbiter using its HiRISE camera on Sept. 8, 2022. NASA/JPL-Caltech/University of Arizona Each northern spring is a little different, with variations leading to ice sublimating faster or slower, controlling the pace of all these phenomena on the surface. And these strange phenomena are just part of the seasonal changes on Mars: the southern hemisphere has its own unique activity.
More About MRO
The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA’s Science Mission Directorate, Washington.
For more information, visit:
https://science.nasa.gov/mission/mars-reconnaissance-orbiter
News Media Contacts
Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
2024-177
Share
Details
Last Updated Dec 20, 2024 Related Terms
Mars Reconnaissance Orbiter (MRO) Jet Propulsion Laboratory Mars Explore More
5 min read Cutting-Edge Satellite Tracks Lake Water Levels in Ohio River Basin
Article 3 days ago 5 min read NASA Mars Orbiter Spots Retired InSight Lander to Study Dust Movement
Article 4 days ago 5 min read NASA’s Perseverance Rover Reaches Top of Jezero Crater Rim
Article 1 week ago Keep Exploring Discover Related Topics
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
By NASA
Download PDF: Statistical Analysis Using Random Forest Algorithm Provides Key Insights into Parachute Energy Modulator System
Energy modulators (EM), also known as energy absorbers, are safety-critical components that are used to control shocks and impulses in a load path. EMs are textile devices typically manufactured out of nylon, Kevlar® and other materials, and control loads by breaking rows of stitches that bind a strong base webbing together as shown in Figure 1. A familiar EM application is a fall-protection harness used by workers to prevent injury from shock loads when the harness arrests a fall. EMs are also widely used in parachute systems to control shock loads experienced during the various stages of parachute system deployment.
Random forest is an innovative algorithm for data classification used in statistics and machine learning. It is an easy to use and highly flexible ensemble learning method. The random forest algorithm is capable of modeling both categorical and continuous data and can handle large datasets, making it applicable in many situations. It also makes it easy to evaluate the relative importance of variables and maintains accuracy even when a dataset has missing values.
Random forests model the relationship between a response variable and a set of predictor or independent variables by creating a collection of decision trees. Each decision tree is built from a random sample of the data. The individual trees are then combined through methods such as averaging or voting to determine the final prediction (Figure 2). A decision tree is a non-parametric supervised learning algorithm that partitions the data using a series of branching binary decisions. Decision trees inherently identify key features of the data and provide a ranking of the contribution of each feature based on when it becomes relevant. This capability can be used to determine the relative importance of the input variables (Figure 3). Decision trees are useful for exploring relationships but can have poor accuracy unless they are combined into random forests or other tree-based models.
The performance of a random forest can be evaluated using out-of-bag error and cross-validation techniques. Random forests often use random sampling with replacement from the original dataset to create each decision tree. This is also known as bootstrap sampling and forms a bootstrap forest. The data included in the bootstrap sample are referred to as in-the-bag, while the data not selected are out-of-bag. Since the out-of-bag data were not used to generate the decision tree, they can be used as an internal measure of the accuracy of the model. Cross-validation can be used to assess how well the results of a random forest model will generalize to an independent dataset. In this approach, the data are split into a training dataset used to generate the decision trees and build the model and a validation dataset used to evaluate the model’s performance. Evaluating the model on the independent validation dataset provides an estimate of how accurately the model will perform in practice and helps avoid problems such as overfitting or sampling bias. A good model performs well on
both the training data and the validation data.
The complex nature of the EM system made it difficult for the team to identify how various parameters influenced EM behavior. A bootstrap forest analysis was applied to the test dataset and was able to identify five key variables associated with higher probability of damage and/or anomalous behavior. The identified key variables provided a basis for further testing and redesign of the EM system. These results also provided essential insight to the investigation and aided in development of flight rationale for future use cases.
For information, contact Dr. Sara R. Wilson. sara.r.wilson@nasa.gov
View the full article
-
By USH
The ongoing mystery surrounding recent drone sightings has become increasingly complex, with conflicting reports making it difficult to draw definitive conclusions. However, a new and intriguing element has emerged alongside these drones sightings: numerous accounts of mysterious orbs, potentially of alien origin, flying at both low and high altitudes.
Reports of mysterious orbs have been increasing in recent weeks. These orbs have been sighted at both high altitudes and closer to urban areas.
Orb sighting over New Jersey on December 17, 2024Watch video UFO Sightings Daily
Pilots have reported encounters to air traffic control. Listen to conversations between pilots and traffic control.
And a passenger aboard United Airlines flight UA2359 from Chicago to Newark recently captured footage of these mysterious orbs. The video, shared online by the user “EasilyAmusedEE” on December 16, 2024, shows objects at altitudes between 40,000 and 50,000 feet—far beyond the capabilities of consumer drones. The footage was reportedly taken using an iPhone 16 Pro Max.
Video plane passenger films unknown orbs.
About the drone sightings: Meanwhile, eyewitness accounts describe these so-called drones as crafts that emit no noise, suggesting advanced technology. Additionally, there are claims that these crafts seem to intentionally draw attention, as they have reportedly interfered with cars (lamps flickering), electronics, streetlights (lamps flickering), and even fully charged batteries, which are said to be instantly drained in their presence.
Video shows among other (drone/orb) sightings, cars lamps flickering, streetlights lamps flickering, fully charged batteries drained.
This surge in Orb sightings raises more questions. Are these orbs extraterrestrial in origin? Could they be deliberately associated with the drone phenomena, or is their timing coincidental? Some suggest the possibility of a false flag operation, hinting at a deeper and potentially misleading agenda by the U.S. government.
Whether these drones and Orbs sightings point to advanced human technology, extraterrestrial activity, or a mix of both, one thing is clear: there is something significant going on.View the full article
-
By European Space Agency
Step into the holidays with this picturesque ‘winter wonderland’ scene at the south pole of Mars, captured by ESA’s Mars Express.
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.