Morning Frost on Mars. Image credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University
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It’s getting a little nippy at night on Mars. The Phoenix lander’s Surface Stereo Imager took this image at 6 a.m. on Sol 79 (August 14, 2008 here on Earth), and a thin layer of water frost is visible on the ground around the landing area. From subsequent images, the frost begins to disappear shortly after this image was taken as the sun rises on the Phoenix landing site.
The sun was about 22 degrees above the horizon when the image was taken, enhancing the detail of the polygons, troughs and rocks around the landing site.
This view is looking east southeast with the lander’s eastern solar panel visible in the bottom lefthand corner of the image. The rock in the foreground is informally named “Quadlings” and the rock near center is informally called “Winkies.”
This false color image has been enhanced to show color variations.
Earlier images taken in June, and put together here in sequence to form a movie, appears to show frost forming on Phoenix’s own legs.
What appears to be frost appears on Phoenix's legs. Credit: Wanderingspace.net
But this isn’t the first time that frost has been imaged on Mars. The Viking lander took the picture below in 1979 of its landing site at Utopia Planetia showing ample amounts of frost on the surface. frost on Mars in a photograph taken by the Viking 2 lander on May 18, 1979. NASA/JPL
In other news, the Phoenix lander also announced on Twitter that it has opened another TEGA oven door in preparation for receiving another sample of Martian soil to “bake and sniff.”
3-D image of a dust grain from Phoenix's Atomic Force Microscope. Credit: NASA/JPL/Caltech/U of Arizona/U of Neuchatel
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What is Mars ubiquitous dust really like, close-up? Scientists from the Phoenix missions are finding out with the Atomic Force Microscope (AFM), an instrument that is providing the highest magnification of anything seen from another world. A couple of months ago the Phoenix Mars Lander used its optical microscope to image small grains of the Martian soil. Now, the spacecraft has switched on the AFM to take the first-ever 3-dimensional image of a single particle of Mars’ dust. The AFM can detail the shapes of particles as small as about 100 nanometers, about one one-thousandth the width of a human hair. That is about 100 times greater magnification the optical microscope. The article is rounded, and about one micrometer, or one millionth of a meter, across. It is a speck of the dust that cloaks Mars. Such dust particlets color the Martian sky pink, feed storms that regularly envelop the planet and produce Mars’ distinctive red soil.
“This is the first picture of a clay-sized particle on Mars, and the size agrees with predictions from the colors seen in sunsets on the Red Planet,” said Phoenix co-investigator Urs Staufer of the University of Neuchatel, Switzerland, who leads a Swiss consortium that made the microscope.
“Taking this image required the highest resolution microscope operated off Earth and a specially designed substrate to hold the Martian dust,” said Tom Pike, Phoenix science team member from Imperial College London. “We always knew it was going to be technically very challenging to image particles this small.”
AFM's 8 sharp tips. Image: NASA
The device took about a dozen years to develop. The AFM maps the shape of particles in three dimensions by scanning them with a sharp tip at the end of a spring. During the scan, invisibly fine particles are held by a series of pits etched into a substrate microfabricated from a silicon wafer.
“I’m delighted that this microscope is producing images that will help us understand Mars at the highest detail ever,” Staufer said. “This is proof of the microscope’s potential. We are now ready to start doing scientific experiments that will add a new dimension to measurements being made by other Phoenix lander instruments.”
“After this first success, we’re now working on building up a portrait gallery of the dust on Mars,” Pike added.
Mars’ ultra-fine dust is the medium that actively links gases in the Martian atmosphere to processes in Martian soil, so it is critically important to understanding Mars’ environment, the researchers said. Phoenix's robotic arm scoop brought a sample of soil to MECA, which includes the AFM. Image: NASA/JPL/Caltech/U of Arizona
The particle seen in the atomic force microscope image was part of a sample scooped by the robotic arm from the “Snow White” trench and delivered to Phoenix’s microscope station in early July. The microscope station includes the optical microscope, the atomic force microscope and the sample delivery wheel. It is part of a suite of tools called Phoenix’s Microscopy, Electrochemistry and Conductivity Analyzer.
Images and data from the Mars Reconnaissance Orbiter (MRO) have revealed layers of clay-rich rock that suggests abundant water was once present on Mars. Scientists from the SETI Institute, the Jet Propulsion Laboratory and several universities have been studying data focused on the Mawrth Vallis area on Mars’ northern highland region. This is a heavily cratered, ancient area of the Red Planet whose surface geology resembles a dried-up, river valley through which water may have flowed. While their findings don’t provide evidence for life, it does suggest widespread and long-term liquid water in Mars’ past.
The researchers used the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard MRO to examine infrared light reflected from clays situated in the many-kilometer wide channel of Mawrth Vallis.
The infrared spectra from CRISM show an extensive swath of phyllosilicate-bearing material. This is a type of iron and magnesium-rich clay that forms in liquid water, and can be found on Earth in oceans and river beds. It is familiar to anyone who’s nearly broken a shovel while trying to plant a tree. There is also evidence in the spectra for hydrated silica, which in its pure, clean form is known as opal.
The researchers combined their data on the composition of soils in this region with topographic information collected by MOLA, the Mars Orbiter Laser Altimeter, on board the Mars Global Surveyor spacecraft. They found layered aluminum clays lying on top of hydrated silica and iron/magnesium clays. These clays were likely formed when water came in contact with basalt – which is the dominant component of the Martian highlands, and probably was produced from volcanic ash, which once blanketed the planet.
CRISM image overlayed with MOLA data of Mawrth Vallis. This covers an area about 10 kilometers (6.2 miles) wide. Fe/Mg-phyllosilicate is shown in red, Al-phyllosilicate is shown in blue, hydrated silica and an Fe2+ phase are shown in yellow/green.
“We were surprised by the variety of clay minerals in this region,†says Janice Bishop of the SETI Institute. “But what’s interesting is that we find the same ordering of the clay materials everywhere in Mawrth Vallis. It’s like a layer-cake of clays, one on top of another. All these layers are topped with a ‘frosting’ of lava and dust. We can see the clay layers where an impact crater has carved a hole through the surface or where erosion has exposed them.â€
Since phyllosilicates have been found in a number of outcrops on Mars in CRISM images, these new data suggest that whatever mechanism formed clays at Mawrth Vallis has probably operated over much greater areas of the Red Planet. Alteration by liquid water may have been widespread on early Mars.
Bishop is careful to note that this work is part of the long-term effort to establish just how widespread, and for what period of time, liquid water may have existed on Mars.
“This is not evidence for life,†she notes. “But it does suggest the long-term and common presence of liquid water – and concomitant active chemistry – on the Red Planet in the distant past.â€
The trench known as Snow White on Sol 43 (NASA/JPL/UA)
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It’s been a busy few days for the Phoenix Mars lander rumour-mill. On Friday, an article was published in Aviation Week reporting an undisclosed source from the NASA team analysing results from the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) had come forward saying Phoenix scientists were in communication with the White House. Apparently there had been new, “provocative” results to come from the MECA, possibly a bigger discovery than last Thursday’s announcement about the scientific proof of water in the Martian regolith. Naturally, the blogosphere went crazy in response to this news. Yesterday, the Phoenix team issued a press release focussing on conflicting results from the MECA and Thermal and Evolved-Gas Analyzer (TEGA) instruments. A MECA sample was found to contain a toxic substance known as perchlorate, usually an oxidizing by-product from industrial processes here on Earth. However, a recently analysed sample from the TEGA turned up no supporting evidence for perchlorate. The study is ongoing. Today, the Phoenix team organized a press conference to discuss a more positive view on the possible discovery of perchlorate, and fired back at recent allegations that science was being withheld from the public…
The Phoenix mission has had an outstanding record of transparency and communicating its science into the public domain. So, one can understand the frustration mission scientists felt when “outrageous” stories (according to Peter Smith, Phoenix principal investigator) were circulated by Aviation Week alleging secrecy about Phoenix findings, strongly indicating that something huge had been discovered and the White House had to be notified. “We want to set the record straight…we’re not with-holding anything” NASA spokesman Dwayne Brown declared at the special press briefing today. The Phoenix team went on to say that the sketchy details in the Aviation Week article led to the huge amount of “speculation” that was thrown around in follow-up stories.
Indeed, there was a significant finding in the works, but the scientists needed more time to analyse the results before issuing a press release on finding perchlorate in the MECA sample. Although the Aviation Week article did specifically say Phoenix was not capable of discovering life, it didn’t stop a number of reports indicating that life had been discovered on the Red Planet (hence the need to communicate the discovery with the President’s Science Advisor first). These speculative claims reached fever-pitch, prompting Phoenix’s Twitter feed to state “Heard about the recent news reports implying I may have found Martian life. Those reports are incorrect.” The speed at which these rumours spread was startling and probably took NASA completely off-guard. This is probably why the perchlorate discovery was announced before a complete and rigorous study could be carried out.
So is perchlorate the death-nail for the possibility of finding suitable conditions for life to be seeded? According to Phoenix scientists, oxidizing chemicals are not always ‘bad news’ for life. “It does not preclude life on Mars. In fact it is a potential energy source,” said William Boynton of the University of Arizona. Indeed, perchlorates have been found in Chile’s highly arid Atacama Desert, a location often used as an analogue for the Martian landscape. Organics in nitrate deposits associated with perchlorates have been found in these harsh conditions, possibly indicating life may form in similar circumstances on Mars.
Although the Phoenix scientists are fairly upbeat about this new finding, other scientists not associated with the mission are cautious. At first glance, perchlorate “is a reactive compound. It’s not usually considered an ingredient for life,” said Brown University geologist John Mustard. Regardless, we will have to wait until all the results are in, especially from the follow-up TEGA sample. Jumping to conclusions are obviously not very helpful to the Phoenix team currently trying to decipher what they are seeing from experiments being carried out by a robot, 400 million miles away.
The surface zones where samples have been excavated by Phoenix (NASA)
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It would appear that the US President has been briefed by Phoenix scientists about the discovery of something more “provocative” than the discovery of water existing on the Martian surface. This news comes just as the Thermal and Evolved Gas Analyzer (TEGA) confirmed experimental evidence for the existence of water in the Mars regolith on Thursday. Whilst NASA scientists are not claiming that life once existed on the Red Planet’s surface, new data appears to indicate the “potential for life” more conclusively than the TEGA water results. Apparently these new results are being kept under wraps until further, more detailed analysis can be carried out, but we are assured that this announcement will be huge…
So why is there all this secrecy? According to scientists in communication with Aviation Week & Space Technology, the next big discovery will need to be mulled over for a while before it is announced to the world. In fact, the Jet Propulsion Laboratory science team for the MECA wet-chemistry instrument that made these undisclosed findings were kept out of the July 31st news conference (confirming water) so additional analysis could be carried out, avoiding any questions that may have revealed their preliminary results. They have also made the decision to discuss the results with the Bush Administration’s Presidential Science Advisor’s office before a press conference between mid-August and early September.
Although good news, Thursday’s announcement of the discovery of water on Mars comes as no surprise to mission scientists and some are amused by the media’s reaction to the TEGA results. “They have discovered water on Mars for the third or fourth time,” one senior Mars scientist joked. These new MECA results are, according to the Phoenix team, a little more complex than the water “discovery.” Scientists are keen to point out however, that this secretive news will in no way indicate the existence of life (past or present) on Mars; Phoenix simply is not equipped make this discovery. What it can do is test the Mars soil for compounds suitable to support life. The MECA instrument does have microscopes capable of resolving bacterial-scale life forms however, but this is not the focus of the forthcoming announcement, sources say.
This new MECA discovery, combined with TEGA data will probably expose something more compelling, completing another piece of the puzzle in the search for the correct conditions for life as we know it to survive on Mars. Critical to this search is to understand how the recently confirmed water and Mars regolith behave together under the Phoenix lander in the cold Martian arctic.
The MECA instrument had already made the landmark discovery that Mars “soil” was much like the soil more familiar on Earth. This finding prompted scientists to indicate that the minerals and pH levels in the regolith could support some terrestrial plants, indicating this would be useful for future Mars settlers.
What with the discovery of water, and the discovery that Mars soil is very much like the stuff we find on Earth, it is hard to guess as to what the MECA’s second soil test has discovered. What ever it is, it sounds pretty significant, especially as NASA and the University of Arizona are taking extraordinary steps to avoid any more details being leaked to the outside world. I just hope were not getting excited over something benign…
So what will this compelling discovery be? Leave your guess below…
Stair-Stepped Mounds in Meridiani Planum. Credit: NASA/JPL/University of Arizona
Meridiani Planum on Mars, where the Mars Rover Opportunity has been traversing the past four plus years, is not just covered with flat, endless plains. Of course, Opportunity has been entering and studying a few of the craters in the region.
Latest panorama from Mars. Credit: NASA/JPL/Caltech/U of Arizona
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The Phoenix Mars lander finally was successful in delivering a fairly fresh sample of Martian soil to the Thermal and Evolved Gas Analyzer (TEGA) oven on Wednesday and a “bake and sniff” test identified water in the soil sample. “We have water,” said William Boynton of the University of Arizona, lead scientist for TEGA. “We’ve seen evidence for this water ice before in observations by the Mars Odyssey orbiter and in disappearing chunks observed by Phoenix last month, but this is the first time Martian water has been touched and tasted.”
The soil sample came from a trench approximately 2 inches deep. When the robotic arm first reached that depth, it hit a hard layer of frozen soil. Two attempts to deliver samples of icy soil on days when fresh material was exposed were foiled when the samples became stuck inside the scoop. Most of the material in Wednesday’s sample had been exposed to the air for two days, letting some of the water in the sample vaporize away and making the soil easier to handle.
“Mars is giving us some surprises,” said Phoenix principal investigator Peter Smith of the University of Arizona. “We’re excited because surprises are where discoveries come from. One surprise is how the soil is behaving. The ice-rich layers stick to the scoop when poised in the sun above the deck, different from what we expected from all the Mars simulation testing we’ve done. That has presented challenges for delivering samples, but we’re finding ways to work with it and we’re gathering lots of information to help us understand this soil.” Phoenix's Workspace on Mars. Credit: NASA/JPL/Caltech/U of Arizona
Also at the press conference announcing the results, NASA also announced a mission extension for Phoenix, through Sept. 30. The original prime mission of three months ends in late August. The mission extension adds five weeks to the 90 days of the prime mission.
“Phoenix is healthy and the projections for solar power look good, so we want to take full advantage of having this resource in one of the most interesting locations on Mars,” said Michael Meyer, chief scientist for the Mars Exploration Program at NASA Headquarters in Washington.
During the mission extension, the science team will attempt to determine whether the water ice ever thaws enough to be available for biology and if carbon-containing chemicals and other raw materials for life are present.
A full-circle, color panorama of Phoenix’s surroundings was recenlty completed by the spacecraft.
“The details and patterns we see in the ground show an ice-dominated terrain as far as the eye can see,” said Mark Lemmon of Texas A&M University, lead scientist for Phoenix’s Surface Stereo Imager camera. “They help us plan measurements we’re making within reach of the robotic arm and interpret those measurements on a wider scale.”
Hi-Res Phobos. Credits: ESA/ DLR/ FU Berlin (G. Neukum)
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On July 23, Europe’s Mars Express spacecraft flew only 93 kilometers from Mars’ moon Phobos, and took the most detailed images ever of the small, irregular moon. Additionally, the spacecraft made other close flybys during the past few weeks, and creating a variety of images. The moon’s grooved surface can be seen in the pictures quite clearly, but the origin of the grooves is not known. They could have been formed by ejecta thrown up from impacts on Mars, or if they could be caused by internal fissures result from the surface regolith, or soil, slipping into internal fissures. Whatever the cause, enjoy these new hi-resolution images of Phobos.
Phobos flyby. Credits: ESA/ DLR/ FU Berlin (G. Neukum)
The best images taken by Mars Express have a resolution of 3.7 m/pixel and are taken in five channels different channels to create 3-D images, and to analyze the physical properties of the surface. Measuring 27 km × 22 km × 19 km, Phobos is one of the least reflective objects in the Solar System, thought to be a capture-asteroid or a remnant of the material that formed the planets.
A Russian sample return mission called Phobos-Grunt (Phobos soil), is scheduled to launch in 2009. It is expected to land on the far-side of Phobos at a region between 5° south to 5° north, and 230° west to 235° west. This region was last imaged in the 1970s by the Viking orbiters. The inset here shows potential landing sites for the Russian mission. Phobos. Credits: ESA/ DLR/ FU Berlin (G. Neukum)
The images obtained by several other spacecraft so far have either been of a lower resolution, or not available in 3D and have not covered the entire disc of Phobos. This is also the first time that portions of the far-side of the moon have been imaged in such high resolution (Phobos always faces Mars on the same side). Mars Express’ High Resolution Camera (HRSC) Super-resolution channel (SRC) image taken on 22 July 2008 from a distance of 4500 km, showing the illuminated edge of the potential landing site of the Russian Phobos-Grunt mission. Phobos in 3-D. Credits: ESA/ DLR/ FU Berlin (G. Neukum)
The imaging team is still working on producing additional images of the moon, including more in 3-D like this one. Managing the close fly-bys was an operational challenge, made possible by spacecraft operations engineers and scientists who worked together to specially optimise Mars Express’s trajectory and obtain the best possible views.
Snow Queen is changing! Credit: NASA/JPL/Caltech/U of Arizona
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The bright, hard surface feature beneath the Phoenix Mars Lander has visibly changed from when it was first imaged shortly after the lander touched down on the Red Planet. Scientists believe the area, called “Snow Queen” could possibly be ice. Thruster exhaust blew away surface soil covering Snow Queen as Phoenix landed, exposing a hard layer with several smooth, rounded cavities. Phoenix’s Robotic Arm Camera (RAC) took its first close-up image of the area under the lander on May 31, the sixth sol of the mission. Now, more than 60 days since landing, cracks as long as 10 centimeters, or about four inches, have appeared in Snow Queen. A seven-millimeter (less than one-third inch) pebble or clod not seen there before has popped up on the surface, and some smooth texture has subtly roughened. These changes have been occurring slowly. “Images taken since landing showed these fractures didn’t form in the first 20 sols of the mission,” Phoenix co-investigator Mike Mellon of the University of Colorado, Boulder, said. “We might expect to see additional changes in the next 20 sols.”
Mellon said long-term monitoring of Snow Queen and other icy soil cleared by Phoenix landing and trenching operations is unprecedented for science. It’s the first chance to see visible changes in Martian ice at a place where temperatures are cold enough that the ice doesn’t immediately sublimate, or vaporize, away. Phoenix scientists discovered that centimeter-sized chunks of ice scraped up in the Dodo-Goldilocks trench lasted several days before vanishing.
“I’ve made a list of hypotheses about what could be forming cracks in Snow Queen, and there are difficulties with all of them,” Mellon said.
One possibility is that temperature changes over many sols, or Martian days, have expanded and contracted the surface enough to create stress cracks. It would take a fairly rapid temperature change to form fractures like this in ice, Mellon said.
Another possibility is the exposed layer has undergone a phase change that has caused it to shrink. An example of a phase change could be a hydrated salt losing its water after days of surface exposure, causing the hard layer to shrink and crack. “I don’t think that’s the best explanation because dehydration of salt would first form a thin rind and finer cracks,” Mellon said. May 31 image of ice under Phoenix. Credit: NASA/JPL/Caltech/U of Arizone
“Another possibility is that these fractures were already there, and they appeared because ice sublimed off the surface and revealed them,” he said.
As for the small pebble that popped up on Snow Queen after 21 sols — it might be a piece that broke free from the original surface or it might be a piece that fell down from somewhere else. “We have to study the shadows a little more to understand what’s happening,” Mellon said.
Meanwhile, scientists and engineers for the mission are studying the icy soil on Mars, examining how it interacts with the scoop on the lander’s robotic arm, trying different techniques to deliver a sample to the TEGA or Thermal and Evolved Gas Analyzer instrument.
“It has really been a science experiment just learning how to interact with the icy soil on Mars — how it reacts with the scoop, its stickiness, whether it’s better to have it in the shade or the sunlight,” said Phoenix Principal Investigator Peter Smith of the University of Arizona.
Last weekend, the team tried two different methods to pick up and deliver a sample of icy soil to one of the ovens in TEGA. In both cases, most of the sample stuck inside the lander’s scoop, with only a small amount of soil getting into the oven. All the data received from the lander – both images and other data — indicated that not enough soil had been funneled into the oven to prompt the oven to close and begins its analysis.
The team plans to keep gaining experience in handling the icy soil while continuing with other Phoenix studies of the soil and the atmosphere.
Smith said, “While we continue with determining the best way to get an icy sample, we intend to proceed with analyzing dry samples that we already know how to deliver. We are going to move forward with a dry soil sample.”
Phoenix's scoop hovers over TEGA. Credit: NASA/JPL/Uof Arizona
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NASA’s Phoenix Mars Lander scraped up some icy soil with its robotic arm and scoop and then attempted to quickly deliver the sample to the oven on board. But not enough soil made it to the oven; the icy soil stuck to the scoop. Engineers determined the rasping and scraping activity collected a total of 3 cubic centimeters of icy soil, more than enough to fill the tiny oven cell of the Thermal and Evolved-Gas Analyzer, or TEGA. However, images returned from the lander Saturday showed that much of the soil remained lodged in the robotic arm’s scoop after the delivery attempt. “Very little of the icy sample made it into the oven,†said Barry Goldstein, Phoenix project manager. “We believe that the material that was intended for the targeted cell is the material that adhered to the back of the scoop.â€
Once the sample had been collected, the robotic arm tilted its scoop and ran the rasp motor several times in an attempt to sprinkle the sample into the oven whose doors were wide open. The scoop was then inverted directly over the doors. A screened opening over the oven measures about 10 centimeters (4 inches) long by 3 centimeters (1.5 inches) wide. The oven itself is roughly the size of an ink cartridge in a ballpoint pen.
But TEGA’s sensors didn’t detect enough soil in the oven for the oven doors to close. Commands were also sent to vibrate the screen on TEGA several times. The good news there is that the vibrating did not cause the oven to short circuit, a problem that occurred earlier and engineers have been worried that vibrating could possibly short out the entire instrument. But TEGA lives on for the team to try again to quickly deliver the icy soil to the oven before the ice sublimates away in Mars thin atmosphere. The ice can exist just under Mars surface, protected by the soil.
Goldstein said the team will adjust their sample drop-off strategy and try again.
