The Mars Reconnaissance Orbiter using its Mars Climate Sounder instrument. Credit: JPL
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The Mars Reconnaissance Orbiter has been circling Mars for over two years now, and has provided unprecedented views of the Red Planet with its HiRISE Camera. But did you also know that MRO is a weather-monitoring satellite, too? The Mars Climate Sounder instrument is examining the Martian atmosphere and has issued its first Mars weather report. “It has taken 20 years and three missions but we finally have an instrument in orbit that gives us a detailed view of the entire atmosphere of Mars and it is already giving us fresh insights into the Martian climate,” said Professor Fred Taylor of Oxford University. Within a paper issued by the Mars ‘weather team’ comes surprising news: during the freezing Martian winter the atmosphere above the planet’s South Pole is considerably warmer than predicted.
The team discovered that even in the depths of the Martian winter, when the planet’s South Pole is frozen and in total darkness, at an altitude of 30-80km the atmosphere is being heated to 180 Kelvin – that’s 10-20 Kelvin warmer than expected.
“Winter at the Martian South Pole is severe even by the standards of our Antarctic,” said Professor Taylor. “The Pole is shrouded in total darkness for many months and the carbon dioxide in the atmosphere freezes, creating blizzards and causing a thick layer of carbon dioxide ice to form across the surface. Yet what we’ve found is that 30 kilometers above the surface conditions are very different.”
The team, which also included Oxford physicists Dr Pat Irwin and Dr Simon Calcutt, believe that a vigorous circulation of the atmosphere – from the Martian equator to the Pole – is compressing the gas and causing the heating effect.
“It’s the same effect that warms the cylinder of a bicycle pump, or the pistons of a car engine, when you compress the gas inside,” said Taylor. “What we think we are observing is that the ‘engine’ of the Martian climate – this atmospheric circulation – is running as much as 50 per cent faster than our models predicted, resulting in this warming of the South Pole.”
These are just the first results from what the scientists hope will be many more years of study. In the long-term they hope to shed light on climate change on Mars, what controls it and what lessons can be drawn for climate change on Earth.
Studying the Martian climate helps us understand how a planet that was originally similar to Earth turned out so very different.
The team’s paper, ‘Intense polar temperature inversion in the middle atmosphere on Mars’, was published in Nature Geoscience on Oct. 12, 2008.
Translucent ice and sand dunes in North Polar Region (NASA/JPL/University of Arizona)
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As the Phoenix Mars lander will agree, it’s cold near Mars’ North Pole. Phoenix is currently seeing the winter frost encroach on its location, bright patches of ice appearing on the rocks surrounding it. Another sure sign of winter at this high latitude is the loss of light; soon day will turn to night, forcing Phoenix to enter a Sun-deprived coma. But as one Mars mission draws to a close, other missions continue their diligent watch over the planet 24/7. One such mission is NASA’s Mars Reconnaissance Orbiter (MRO), using its High Resolution Imaging Science Experiment (or HiRISE for short) to pick out the tiny surface features on the Red Planet from around 320 km (200 miles) above.
As winter sets in on the Martian northern hemisphere, HiRISE continues to capture some stunning images of the translucent icy surface…
Mars dune detail showing the southwesterly dominant wind direction (NASA/JPL/HiRISE)These images were acquired at the end of August by HiRISE, and it is evident there was plenty of ice on the surface of this northern region. The MRO was making a pass over a geographical latitude of 77° when these pictures were taken, capturing the complex cracking of translucent surface ice, contrasting with the dark sand of a vast number of barchan dunes, a feature we often observe on Earth as well as on Mars. Phoenix landed at 68° latitude, a little further south than these HiRISE images, but it can be seen there is a lot more ice for that time of the year only 10° further north of Phoenix’s location (after all, no surface frost was observed by the lander in August).
It is thought that the bright areas of ice in the image above comes from surface frost deposited the previous year, but the polar temperatures remained so cold throughout the Martian summer that the frost didn’t sublimate into the thin atmosphere. So, the surface ice remained throughout the year, gradually undergoing physical changes, creating a polygonal texture when viewed from orbit. The texture was probably down to temperature variations, stressing and cracking the ice.
Looking at the detail of the sand dunes, it becomes apparent that the dunes are still active despite the icy surroundings. The streaks of loose sand appear to indicate a dominant southwesterly wind direction.
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The Mars Science Laboratory, the next generation of Mars rovers slated to head to Mars in 2009, is still alive, for the time being. The car-sized rover designed to look for life on Mars is over budget and behind schedule due to technical problems, and NASA officials met today to discuss their options. Potentially, Congress could pull the plug on the mission if cost overruns go too high. NASA Administrator Mike Griffin and Science Associate Administrator Ed Weiler were briefed, and met with mission managers in attempt to work out a potential solution. In a press briefing today, Doug McCuistion, director of the Mars Exploration Program at NASA headquarters said the rover’s progress will be assessed again in January, but the mission will need more money. “This is a really important scientific mission,” McCuistion said. “This is truly the push into the next decade for the Mars program and for the discovery for the potential for life on other planets…I fully believe that Congress will support us as we go forward on this because they recognize the importance of the mission as well.”
The panel of NASA officials at the briefing wouldn’t say where the money will come from or exactly how much will be needed to keep the rover on schedule and provide the engineers the resources they need to overcome the technical problems. But NASA will seek additional money from Congress and/or realign funds from other missions.
“If we’re going to launch in 2009 or 2011 additional budget resources are going to be necessary. The sources of that we cannot release until we get approval from the Office of Management and Budget and Congress,” said McCuistion.
Costs for MSL have already gone from the initial $1.5 billion to $1.9 billion. Launch is scheduled sometime between Sept. 15 and Oct. 15, 2009, but could be delayed until 2011 if the problems take more time to be resolved. Earth and Mars come closest to each other approximately every 26 months, providing favorable launch windows.
Problems with parachutes, actuators and other materials have delayed construction of the rover, and currently the contractors are working multiple shifts to make up for lost time. Mission managers hope tests of the rover can begin in November or December.
MSL will be three times as heavy and twice the width of the Mars Exploration Rovers (MERs) that landed in 2004, and will be able to travel twice as far. It will carry ten advanced scientific instruments and cameras. It will make the first precise landing and a predetermined site, using a guided entry system and a soft-landing system called the Sky Crane.
Artist rendition of th ExoFly on Mars. Courtesy Ray Villard
This is perhaps the coolest thing I’ve ever seen. Ray Villard, the news director for the Hubble Space Telescope, also writes a blog for Discovery called Cosmic Ray (love that name!) He recently wrote about a dragonfly-like robotic device being developed by the Technical University Delft, Wageningen University in the Netherlands. It’s call the ExoFly, and Ray described it as a “dragonfly-on-steroids … a nimble flapping aerobot.” It could be the next generation of robotic planetary explorers. It’s a small, lightweight autonomous machine capable of flying, hovering, landing and taking off like an insect. Ray says this type of vehicle would “open up a new exploration niches that it not easily reachable by rovers or airborne vehicles on far flung worlds.” Actually, it might work best in conjunction with a future big rover, flying ahead to search for interesting or dangerous terrain, and the rover would provide a “landing pad” for the ExoFly’s home base. While the ExoFly may be small, its name sounds like a potential super hero, and its capabilities could be in the exploration super hero category, as well.
Take a look at the incredible video of the ExoFly below:
The ExoFly would be great for exploring Mars, and Titan, too. Small onboard cameras would provide a unique overhead but close-up view of the terrain in geological terms that would be different from, and could compliment, a rover.
The prototype ExoFly weighs less than an ounce, has a wingspan of only a foot, and can fly for 12 minutes on batteries.
A Mars ExoFly would need a longer wingspan and carry a miniaturized high-resolution digital video camera, sensors, navigation system and instruments.
Check out all of Ray Villard’s ideas for this future flying robot at Cosmic Ray.
Image and video credit: T.E. Zegers
Source: Cosmic Ray (with a head nod to Disco Dave Mosher for his Twitter Tweet)
Artists depiction of Odyssey at Mars. Credit: NASA
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Seems like everyone at Mars is getting an extended mission these days – every spacecraft, that is. The Mars Odyssey orbiting spacecraft, the longest-serving of six spacecraft now studying Mars, has gotten another two-year extension of its mission. And mission extensions are great opportunities to try something new, so Odyssey is altering its orbit to get a different and better look at Mars with its Thermal Emission Imaging System which maps minerals on Mars in infrared. During this third mission extension, which goes through September 2010, Odyssey will also be able to point its camera with more flexibility than ever before. Odyssey is another Energizer Bunny-like spacecraft: it has been going and going since it reached Mars in 2001.
The orbit adjustment will allow Odyssey’s Thermal Emission Imaging System to look down at sites when it’s mid-afternoon, rather than late afternoon, as it has been doing so far. The multipurpose camera will take advantage of the infrared radiation emitted by the warmer rocks to provide clues to the rocks’ identities.
“This will allow us to do much more sensitive detection and mapping of minerals,” said Odyssey Project Scientist Jeffrey Plaut of NASA’s Jet Propulsion Laboratory, Pasadena , Calif.
The mission’s orbit design before now used a compromise between what works best for the Thermal Emission Imaging System and what works best for another instrument, the Gamma Ray Spectrometer.
To change its orbit, the operations team at JPL and Lockheed Martin Space Systems in Denver fired Odyssey’sthrusters for nearly 6 minutes on Sept. 30, the final day of the mission’s second two-year extension. This image from Odyssey shows a surface changed by floods. Credit: NASA/JPL-Caltech/ASU
“This was our biggest maneuver since 2002, and it went well,” said JPL’s Gaylon McSmith, Odyssey mission manager. “The spacecraft is in good health. The propellant supply is adequate for operating through at least 2015.”
Odyssey’s orbit a sun-synchronous polar orbit at Mars. The local solar time has been about 5 p.m. at whatever spot on Mars Odyssey flew over as it made its dozen daily passes from between the north pole region to the south pole region for the past five years. (Likewise, the local time has been about 5 a.m. under the track of the spacecraft during the south-to-north leg of each orbit.)
From last week’s thruster maneuver, that synchronization will gradually change over the next year or so. Its effect is that the time of day on the ground when Odyssey is overhead is now getting earlier by about 20 seconds per day. A follow-up maneuver, probably in late 2009 when the overpass time is between 2:30 and 3:00 p.m., will end the progression toward earlier times.
This will also allow the camera away to be pointed in different directions, instead of just the straight-down pointing that has been used throughout the mission. Doing this will allow the team to fill in some gaps in earlier mapping and also create some stereo, three-dimensional imaging.
The downside of this is one instrument will likely stop being used. The gamma ray detector, one of three instruments in Odyssey’s Gamma Ray Spectrometer suite, needs a later-hour orbit to avoid overheating of a critical component. But the neutron spectrometer and high-energy neutron detector are expected to keep operating.
The Gamma Ray Spectrometer provided dramatic discoveries of water-ice near the surface throughout much of high-latitude Mars, the impetus for NASA’s Phoenix Mars Lander mission. The gamma ray detector has also mapped global distribution of many elements, such as iron, silicon and potassium, a high science priority for the first and second extensions of the Odyssey mission. A panel of planetary scientists assembled by NASA recommended this year that Odyssey make the orbit adjustment to get the best science return from the mission in coming years.
Odyssey will continue providing crucial support for Mars surface missions as well as conducting its own investigations. It has relayed to Earth nearly all data returned from NASA rovers Spirit and Opportunity . It shares with NASA’s Mars Reconnaissance Orbiter the relay role for Phoenix. It has made targeted observations for evaluating candidate landing sites.
Frost now appears on Mars every sol. Credit: NASA/JPL/Caltech/U of AZ
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The days are getting shorter for the Phoenix Mars Lander, and as fall approaches on Mars’ northern plains, the scientists and engineers for the mission are quickly trying get as much done before power levels on the lander drop too low for any more scientific activities. In the image here, blue-ish white frost appears on Mars surface every day now as the temperatures continue to drop. This image was taken on the 131st Martian day or sol of the mission, October 7 here on Earth. Clearly visible are the interlocking polygon shapes that form in permafrost from seasonal freezes and thaws. These polygon patterns were seen in orbital pictures taken by the Mars Reconnaissance Orbiter, as well as other spacecraft, and are part of the evidence that Mars’ north polar region harbors large quantities of frozen water.
The Phoenix Lander has dug more trenches in Mars soil in both the low troughs and high peaks of the polygons, and is scooping the soil into onboard science laboratories for analysis. About two weeks ago, Phoenix moved a rock nicknamed “Headless,” about 0.4 meters (16 inches) with its robotic arm. Then soil from under the rock was scraped up by the scoop at the end of the arm and and delivered to the lander’s optical and atomic-force microscopes.
Scientists are conducting preliminary analysis of this soil, nicknamed “Galloping Hessian.” The soil piqued their interest because it may contain a high concentration of salts, said Diana Blaney, a scientist on the Phoenix mission with NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
As water evaporates in arctic and arid environments on Earth, it leaves behind salt, which can be found under or around rocks, Blaney said. “That’s why we wanted to look under ‘Headless,’ to see if there’s a higher concentration of salts there.” The La Mancha trench. Credit: NASA/JPL/Caltech/U of AZ
Phoenix scientists also want to analyze a hard, icy layer beneath the Martian soil surface. The robotic arm has dug into a trench called “La Mancha,” in part to see how deep the Martian ice table is. The Phoenix team also plans to dig a trench laterally across some of the existing trenches in hopes of revealing a cross section, or profile, of the soil’s icy layer.
“We’d like to see how the ice table varies around the workspace with the different topography and varying surface characteristics such as different rocks and soils,” said Phoenix co-investigator Mike Mellon of the University of Colorado, Boulder. “We hope to learn more about how the ice depth is controlled by physical processes, and by looking at how the ice depth varies, we can pin down how it got there.” Mars soil on the MECA instrument. Credit: NASA/JPL/Caltech/U of AZ
Over the weekend, on the 128th Martian day, or sol, Phoenix engineers successfully directed the robotic arm to dig in a trench called “Snow White” in the eastern portion of the lander’s digging area. The robotic arm then delivered the material to an oven screen on Phoenix’s Thermal and Evolved-Gas Analyzer.
The Phoenix team will try to shake the oven screen so the soil can break into smaller lumps and fall through for analysis.
The Phoenix lander, originally planned for a three-month mission on Mars, is now in its fifth month. As fall approaches, the lander’s weather instruments detect diffuse clouds above northern Mars, and temperatures are getting colder as the daylight hours wane.
Consequently, Phoenix faces an increasing drop in solar energy as the sun falls below the Martian horizon. Mission engineers and scientists expect this power decline to curtail activities in the coming weeks. As darkness deepens, Phoenix will primarily become a weather station and will likely cease all activity by the end of the year.
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The Mars Science Laboratory, a souped-up Mars rover scheduled to launch next year might be delayed, scaled down or canceled due to technical problems and cost overruns. The nuclear powered rover designed to search for microbial life on the Red Planet, has already cost $1.5 billion and if it reaches a 30-percent cost overrun, it could be cancelled by Congress. Aviation Week reports that officials from the agency’s Mars Exploration Program (MEP) and the Jet Propulsion Laboratory (JPL) will brief NASA Administrator Mike Griffin and Science Associate Administrator Ed Weiler this Friday and attempt to work out a potential solution. Delaying the rover’s mission until 2011 would be costly, but Weiler has said that JPL is so stretched trying to make the 2009 launch window that the result could be “a nuclear crater on Mars.”
Nearly the size of a small car, the proposed MSL will be three times as heavy and twice the width of the Mars Exploration Rovers (MERs) that landed in 2004, and will be able to travel twice as far. It will carry ten advanced scientific instruments and cameras. It will make the first precise landing and a predetermined site, using a guided entry system and a soft-landing system called the Sky Crane. But assembly and testing of critical components and instruments are behind schedule because of technical problems. Entry, descent and landing for MSL. Credit: JPL
Since there’s not much extra cash anywhere in NASA and JPL’s pot, any cost overruns from technical issues or delays would have to be taken from other missions. To keep MSL, NASA could be forced to cancel the $485 million 2013 atmospheric Scout mission MAVEN that was recently announced, or a future rover mission tentatively set for 2016.
A slip to the 2011 launch window will add another $300 million-$400 million to the price tag, but it could be better than trying to launch in 2009 with a rover and team that is potentially unready to fly.
Doug McCuistion, the MEP manager said his program is stretched to its limits, with no funding for technology development and “next to nothing” for education and public outreach.
NASA has been sending a mission to Mars approximately every two years to determine if the planet ever was capable of supporting life.
Direct hit - could a huge impact on Mars have snuffed the chances of life? (Karen Carr)
[/caption]We keep sending missions to Mars with the key objective to search for past or present life. But what if a huge impact early in the Red Planet’s history hindered any future possibility for life to thrive? Recent studies into the Martian “crustal dichotomy” indicate the planet was struck by a very large object, possibly a massive asteroid. Now researchers believe that this same impact may have scrubbed any chance for life on Mars, effectively making the planet sterile. This asteroid may have penetrated the Martian crust so deep that it damaged the internal structure irreparably, preventing a strong magnetic field from enveloping the planet. The lack of a Mars magnetosphere thereby ended any chance for a nurturing atmosphere…
Mars looks odd. Early astronomers noticed it, and today’s observatories see it every time they look at the red globe. Mars has two faces. One face (the northern hemisphere) is composed of barren plains and smooth sand dunes; the other face (the southern hemisphere) is a chaotic, jagged terrain of mountains and valleys. It would appear the crustal dichotomy formed after a massive impact early in the development of Mars, leaving the planet geologically scarred for eternity. But say if this impact went beyond pure aesthetics? What if this planet-wide impact zone represents something a lot deeper?
To understand what might have happened to Mars, we have to first look at the Earth. Our planet has a powerful magnetic field that is generated near the core. Molten iron convects, dragging free electrons with it, setting up a huge dynamo outputting the strong dipolar magnetic field. As the magnetic field threads through the planet, it projects from the surface and reaches thousands of miles into space, forming a vast bubble. This bubble is known as the magnetosphere, protecting us from the damaging solar wind and prevents our atmosphere from eroding into space. Life thrives on this blue planet because Earth has a powerful magnetic solar wind defence.
Although Mars is smaller than Earth, scientists have often been at a loss to explain why there is no Martian magnetosphere. But according to the growing armada of orbiting satellites, measurements suggest that Mars did have a global magnetic field in the past. It has been the general consensus for some time that Mars’ magnetic field disappeared when the smaller planet’s interior cooled quickly and lost its ability to keep its inner iron in a convective state. With no convection comes a loss of the dynamo effect and therefore the magnetic field (and any magnetosphere) is lost. This is often cited as the reason why Mars does not have a thick atmosphere; any atmospheric gases have been eroded into space by the solar wind.
However, there may be a better explanation as to why Mars lost its magnetism. “The evidence suggests that a giant impact early in the planet’s history could have disrupted the molten core, changing the circulation and affecting the magnetic field,” said Sabine Stanley, assistant professor of physics at the University of Toronto, one of the scientists involved in this research. “We know Mars had a magnetic field which disappeared about 4 billion years ago and that this happened around the same time that the crustal dichotomy appeared, which is a possible link to an asteroid impact.”
During Mars’ evolution before 4 billion years ago, things may have looked a lot more promising. With a strong magnetic field, Mars had a thick atmosphere, protected from the ravages of the solar wind within its own magnetosphere. But, in an instant, a huge asteroid impact could have changed the course of Martian history forever.
“Mars once had a much thicker atmosphere along with standing water and a magnetic field, so it would have been a very different place to the dry barren planet we see today.” – Monica Grady, professor of planetary and space sciences at the Open University.
Losing its magnetic field after the deep asteroid impact catastrophically damaged the internal workings of the planet, Mars quickly shed its atmosphere, thereby blocking its ability to sustain life in the 4 billion years since. What a sad story…
We may be able to hear, for the first time, what it sounds like on the surface of Mars. The Phoenix Lander has a microphone on board, which will be switched on in upcoming days of operations. “This is definitely a first,” said Phoenix principal investigator Peter Smith. The microphone is a part of the Mars Descent Imager (MARDI) system on the underside of the lander designed to take images of Mars’ surface during the lander’s descent. However, the system was never used. Tests of the system during the flight to Mars revealed the possibility that using it might cause other parts of the landing system to not function correctly. But using it later wasn’t ruled out. So, after updated software is sent to the lander, the microphone will be turned on.
There’s no guarantee the microphone will work, however. Once the system is checked and updated, the team plans to attempt turning the microphone on while the lander is digging or using the rasp on end of its robotic arm scoop, “just to make sure we hear something,” Smith said. “You at least want to know if there’s a chance of noise being created.”
No one knows what Mars sounds like, and Phoenix scientists aren’t sure how well the microphone will be able to pick up any noise. Smith said the microphone is similar to what is used on a standard cell phone. Also, sound waves don’t travel on Mars as they do Earth because of Mars’ thin atmosphere. It would be similar to listening to sound at an altitude of about 30,500 meters (100,000 feet) above Earth’s surface, Smith said.
If the team can hear Phoenix’s operations, then they’ll turn the microphone on while Phoenix is quiet and wait for any sounds.
Additionally, the descent imager might be turned on, as well. This provides the opportunity to take close up images directly underneath the lander, where the “Holy Cow” feature – which appears to be a large chunk of ice – is located.
The imager might also be able to look at the clumps of materials that appear to be “growing” on Phoenix’s legs. The clumps are probably bits of Mars soil that “splashed” up on the legs during landing, but some of the clumps have moved around and appear to be increasing in size over the duration of the mission. Mission scientists aren’t sure what the clumps are and why they have such unusual behavior.
“It’s one of those wonderful Martian mysteries,” Smith said.
Post Script & Corrections: Thanks to Emily Lakdawalla of the Planetary Society for providing the correct image and information of the MARDI! The first image I had posted was of the Mars Microphone that the Planetary Society sent along with the Mars Polar Lander mission in 1999. Also, I incorrectly stated that the MARDI instrument was the same as the Mars Microphone on the MPL.
Clouds on Mars are producing snow. Credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University
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Remember the movies of clouds floating above the Phoenix Lander? Further study with the lander’s Lidar instrument has detected snow falling from Martian clouds. “The clouds are composed of ice crystals, and some of the crystals are large enough to fall through the atmosphere,” said Jim Whiteway, lead scientist for the Meteorological Station on Phoenix. Whiteway and several researchers shared recent findings from Phoenix at a press briefing today. “So snow is falling from the clouds and we are going to be watching very closely over the next month for evidence that the snow is actually landing on the surface. This is a very important factor in the hydrological cycle on Mars, with the exchange of water between the surface and the atmosphere.”
“Nothing like this view has ever been seen on Mars,” Whiteway added.
From Phoenix images and data, scientists have observed water condensing in the atmosphere. In recent weeks, as the temperatures fall in onset of winter on Mars’ northern plains, frost, ground fog and clouds are prevalent. “This is now occurring every night,” said Whiteway. “The Lidar is able to probe the inner structure of the clouds. It emits pulses of light upward into the atmosphere and detects what is scattered back. The laser emits pulses of light 100 times per second, so if you were standing beside the lander looking upward, you’d see a continuous green beam.” Data and images of the beam show bright spots in beam is where it is reflecting off ice crystals, and also where it reflects off clouds, a few miles above the surface.
The snow starts falling from a height of 4 km and fall down to 2 km. At that point the observations stopped, as they were initially set up for a limited amount of time. Further observations will be done to see if the snow is actually falling down to the surface of the planet.
Other experiments with Martian soil have provided evidence of past interaction between minerals and liquid water. Two different instruments have detected calcium carbonate and clays. On Earth, these form only in the presence of liquid water.
How much calcium carbonate or clays are in the soil hasn’t been fully quantified yet, said Bill Boynton, lead scientist for the TEGA Instrument (Thermal and Evolved Gas Analyzer) But at least 3-6 per cent of the soil is calcium carbonate, and about 1 per cent is clay. There were suspicions of carbonates in Mars soil, and now both the TEGA and the MECA instruments have verified their presence.
Both TEGA, and the microscopy part of MECA, have also turned up hints of a clay-like substance. “We are seeing smooth-surfaced, platy particles with the atomic-force microscope, not inconsistent with the appearance of clay particles,” said Michael Hecht, MECA lead scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
However, finding perchlorates in the soil leads to somewhat of a contradiction, as perchlorates would be sensitive to any water present. If large amounts of water were present in the past, the perchlorates should have dissolved. But they didn’t.
Another clue to the Mars soil puzzle is the dryness of the soil. The lander’s thermal and conductivity probe has indicated the soil is extremely dry around the lander, even though just under the surface, ice is present. “The dryness of the soil is a mystery here,” said Phoenix principal investigator Peter Smith. “We’re wondering if the perchlorate is absorbing or sucking up the water. We say dry because there aren’t any thin films of liquid water mixed with salts in the soil.” If percholate are mixed with water, brines could form, but the scientists have not seen evidence of a brine or remnants of a brine with cameras on board Phoenix. Perchlorates, however, are useful to microbes, which can use it as an energy source. “It’s an Interesting material to find on Mars, and there will be more research coming to find out what it might mean on Mars,” said Smith.
Another finding discussed was the pH levels of the soil. Hecht said the pH of the soil has been determined to be 8.3, which is lower than initially thought. Hecht said this is almost exactly the pH of ocean water on Earth, and the calcium carbonate may be responsible for this level of pH. Image NASA/JPL-Caltech/University of Arizona/Imperial College London
Hecht also discussed the unique images from the microscopes on board Phoenix. The first image, shows the soil is mostly composed of fine orange particles, and also contains larger grains, about a tenth of a millimeter in diameter, and of various colors. The soil is sticky, keeping together as a slab of material on the supporting substrate even when the substrate is tilted to the vertical.
The fine orange grains are at or below the resolution of the Optical Microscope. Mixed into the soil is a small amount – about 0.5 percent – of white grains, possibly of a salt. The larger grains range from black to almost transparent in appearance. At the bottom of the image, the shadows of the Atomic Force Microscope (AFM) beams are visible. This image is 1 millimeter x 2 millimeters. Colored magnetic particles in Mars soil. Image NASA/JPL-Caltech/University of Arizona/Imperial College London
The second image shows a cluster of colored particles. “The reason they are all clustered like that is because they are strongly magnetic,” said Hecht. “All the fine red stuff has fallen off leaving all these little “Easter eggs” of all different colors and shapes. The particles are rounded because they’ve been tumbled by the wind across the sand and they’ve been polished. You also see a lot of angular particles that are clear, that are very white as if they are salts. So we can start to see the different animals in the zoo of Martian mineralogy.” Phoenix’s atomoic force microscope will be used in the coming weeks, and Hecht said the team should be able to provide a catalog of different particles found in these images.
