Posted on by Ian O'Neill

Russia Will Send Life to Phobos

Going where no tardigrade has been before

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How ironic. Not content with searching for life on Mars, the Russian space agency and the US-based Planetary Society will soon be sending terrestrial life to the Martian moon Phobos. The mini-interplanetary travellers will consist of bacteria, spores, seeds, crustaceans, insects and fungi. Why? To see how biological life, in various forms, deals with space travel spanning three years.

So if you thought that a human (or monkey) would be the first of Earth’s ambassadors to land on Mars or one of its moons, you’d be very mistaken…

The Phobos-Grunt mission profile
The Phobos-Grunt mission profile
Russia has been carrying out a variety of biological space tests to see how life deals with the hazards of spaceflight recently. In one experiment carried out in collaboration with Japanese scientists, a mosquito was attached to the hull of the International Space Station (ISS) to see… what would happen.

The mosquito was a part of the Biorisk project, and the scientists knew the insect had the ability to drop into a “suspended animation” during times of draught in Africa. The African mosquito can turn its bodily water into tricallosa sugar, slowing its functions nearly to a stop. When the rain returns, the crystallised creature is rehydrated and it can carry on its lifecycle. The Biorisk mosquito however survived 18 months with no sustenance, exposed to temperatures ranging from -150°C to +60°C. When returned to Earth, Russian scientists gave the hardy mozzie a health check, declaring:

“We brought him back to Earth. He is alive, and his feet are moving.” — Anatoly Grigoryev, Vice President of the Russian Academy of Sciences.

©Gerald Yuvallos/Flickr
Quite happy with living in space, the mosquito ©Gerald Yuvallos/Flickr
Was this insect cruelty of the most extreme kind, or did it serve a purpose? Actually, the mosquito experiment provided an insight to a biological specimen after being exposed to cosmic rays for long periods, and it also showed us that the African mosquito’s natural ability to slip into a defensive coma, only to be revived and appear to be healthy (that is, if it was more than just its feet moving – there was no indication as to whether the little guy was successfully re-integrated into mosquito society). Perhaps the lessons learned from this small test may go to some way of helping us realise the potential for putting future interplanetary astronauts into some kind of biological stasis.

So that’s the idea behind sending creatures into space: we need to understand how animals and plants deal with space travel. This will aid the understanding of how humans will cope in space for long periods, plus we need to understand if there are any harmful effects from growing foodstuffs away from our planet. This is why the Russian space agency wants to go one step further when it launches its Phobos-Grunt mission next year, to send biological specimens on a voyage of a lifetime. A return trip to the Martian moon Phobos.

Say hello to our interplanetary ambassador, the tardigrade (FUNCRYPTA)
Say hello to our interplanetary ambassador, the tardigrade (FUNCRYPTA)
On board, it is hoped the US-based Planetary Society will be able to send a small package filled with 10 different species including tardigrades (“water bears”), seeds and bacteria. The main purpose of this experiment will be to test the panspermia hypothesis, where it is thought that life may travel from planet to planet, hitching a ride on fragments of planetary material. Most of the biological samples will be in a dormant state (i.e. the plant spores), and tests will be carried out when Phobos-Grunt returns to Earth to see if the bacteria survived, seeds germinate and spores… do what ever spores do.

Russia on the other hand has far loftier goals; the space agency will attach a small petting zoo. Inside the Russian experiment will include crustaceans, mosquito larvae (already proven to be enthusiastic space travellers), bacteria and fungi. The Russian experiment will specifically look at how cosmic radiation can effect these different types of life during an interplanetary trip (essential ahead of any manned attempt to the Red Planet).

Naturally, there are some concerns about contamination to the moon (if Phobos-Grunt doesn’t do the “return” part of the mission), but the chances of any extraterrestrial life being harboured on this tiny piece of airless rock are low. Having said that, we just don’t know, so the mission scientists will have to be very careful to ensure containment. Besides, there’s something unsettling about infecting an alien world with our bacteria before we’ve even had the chance to get there ourselves…

Source: Discovery

Posted on by Nancy Atkinson

MRO Goes Into Safe Mode

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NASA’s Mars Reconnaissance Orbiter unexpectedly rebooted its computer Monday morning, Feb. 23, and put itself into a limited-activity mode, an automated safety response to an anomalous event such as a cosmic ray hit on part of the electronics on board the spacecraft. This is the fifth time since August of 2005 that the spacecraft has gone into safe mode. However, the symptoms from this week’s event do not match any of the prior safe-mode events. “We are going to bring the spacecraft back to normal operations, but we are going to do so in a cautious way, treating this national treasure carefully,” said Jim Erickson of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., project manager for the Mars Reconnaissance Orbiter. “The process will take at least a few days.”

Safe Mode is a precaution programmed for the spacecraft when it senses a condition for which it does not know a more specific response.

MRO engineers are examining possible causes of the event while planning to prepare the spacecraft to resume its scientific investigations of Mars. There has been no reoccurrence of the reboot event.

The spacecraft is in communication with and under control by the flight team. Its batteries are charged and its solar panels are properly generating electricity. The team successfully commanded an increase of more than 10,000-fold in the communication rate Monday afternoon from the rate of 40 bits per second that the orbiter initially adopted when it went into the precautionary “safe” mode.

From the spacecraft data received after communications accelerated, the team gained a preliminary indication that the cause of the reboot might have been a measurement — possibly erroneous — of a brief increase in power load. The event lasted between 200 nanoseconds and 41 seconds. That leads engineers to identify one possible scenario as a cosmic-ray hit that could have caused an erroneous voltage reading that would last 9 microseconds, enough to trigger the reboot.

The reboot occurred at about 4:25 a.m. Pacific Standard Time on Monday, while the orbiter was behind Mars from Earth’s perspective. Engineers hope to have MRO back functioning normally by early next week.

Source: NASA

Posted on by Anne Minard

Arizona Scientist: We Could All Be Martians

Artist's conception of an fragment as it blasts off from Mars. Boulder-sized planetary fragments could be a mechanism that carried life between Mars and Earth, UA planetary scientist Jay Melosh says. (Credit: The Planetary Society)

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As long as we’re still pondering human origins, we may as well entertain the idea that our ancestor microbes came from Mars.

And Jay Melosh, a planetary scientist from the University of Arizona in Tucson, is ready with a geologically plausible explanation.

Meteorites.

“Biological exchange between the planets of our solar system seem not only possible, but inevitable,” because of meteorite exchanges between the planets, Melosh said. “Life could have originated on the planet Mars and then traveled to Earth.”

jay_melosh
Jay Melosh. Credit: Maria Schuchardt, University of Arizona Lunar and Planetary Lab

Melosh is a long-time researcher who says he’s studied “geological violence in all its forms.” He helped forge the giant impact theory of the moon’s formation, and helped advance the theory that an impact led to the extinction of the dinosaurs 65 million years ago.

He points out that Martian meteorites have been routinely pummeling Earth for billions of years, which would have opened the door for past Mars microbes to hitch a ride. Less regularly, Earth has undergone impacts that sent terrestrial materials flying, and some of those could have carried microbes toward the Red Planet.

“The mechanism by which large impacts on Mars can launch boulder-sized surface rocks into space is now clear,” he said. He explained that a shock wave spreads away from an impact site faster than the speed of sound, interacting with the planetary surface in a way that allows material to be cast off – at relatively low pressure, but high speed.

“Lightly damaged material at very high speeds,” he said, “is the kind of environment where microorganisms can survive.”

Scientists have recent evidence of Earth microbes surviving a few years in space. When the Apollo 12 astronauts landed on the moon, they retrieved a camera from Surveyor 3, an unmanned lander that had touched down nearly three years prior. Earthly microbes – including those associated with the common cold — were still living inside the camera box.

“The records were good enough to show one of the technicians had a cold when he was working on it,” he said.

Scientists also have evidence that microbes can survive for thousands or even hundreds of thousands of years when frozen on Earth, but surviving that long in space would be an entirely different matter, with the bombardment of UV light and cosmic rays. Then again, the microbe Dienococcus radiodurans is known to survive in the cores of nuclear reactors.

Melosh acknowledges that scientists lack proof that such an exchange has actually occurred between Mars and Earth — but science is getting ever closer to being able to track it down. 

LEAD PHOTO CAPTION: Artist’s conception of an fragment as it blasts off from Mars. Boulder-sized planetary fragments could be a mechanism that carried life between Mars and Earth, UA planetary scientist Jay Melosh says. (Painting by Don Davis. Copyright SETI Institute, 1994)

Source: University of Arizona and an interview with Jay Melosh

Posted on by Nancy Atkinson

NASA Funds Development of Mars Balloon

Shielded Mars Balloon Launcher (SMBL) deployment sequence. Credit: Aurora Flight Services

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A future Mars mission could include instruments attached to balloons, providing the capability to study places where rovers can’t go, while offering a closer look than orbiting satellites. NASA has awarded a Small Business Innovative Research (SBIR) Phase I contract to Aurora Flight Sciences and its partner Vertigo Inc, to develop an autonomous balloon launcher to operate from the surface of Mars. Aurora is looking to develop a compact lightweight system that could be included on future Mars landers, augmenting the mission with a small aerial vehicle. Such a system would have potential for atmospheric sampling and video data capture unavailable on current Mars missions.

Balloon-based Mars exploration has the capability to cover a larger portion of the Martian surface than is accessible via a rover and to provide better resolution than is available from satellites. Balloons could be used to measure atmospheric data at different altitudes and locations on Mars.

“A major challenge to ground deployment is the possibility of the envelope being damaged by winds, surrounding rocks, or parts of the associated lander,” said the project’s manager, George Kiwada. “Our Shielded Mars Balloon Launcher (SMBL) concept addresses this challenge by using inflatable structures to provide a safe environment for balloon inflation and deployment.”

Balloons have been flying for decades in Earth’s stratosphere, which has an atmosphere as thin as that on the surface of Mars. Conventional stratospheric balloons have lifetimes limited to a few days because of the daily heating and cooling of the balloon. Helium superpressure balloons, currently under development for the Ultra Long Duration Balloon (ULDB), will fly more than 100 days and perhaps as long as a year. Smaller superpressure balloons carrying payloads of only a few kilograms have already flown for as long as a year.

Aurora’s has done previous work with NASA on the development of a Mars airplane. In that project, Aurora became familiar with the challenges of aerial vehicle operations in the Martian atmosphere.

Source: Aurora Flight Sciences

Posted on by Nancy Atkinson

New HiRISE Images: Winter Turning to Spring in Mars’ Southern Hemisphere

Proctor Crater on Mars during winter. Credit: NASA/JPL/U of AZ

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If you’ve never seen the “Springtime on Mars 2020” video, its a fun (if not Wall-E-ish) view of what Mars could be like sometime in the future. But now in 2009, winter is turning to spring in Mars’ southern hemisphere, and the HiRISE camera on board the Mars Reconnaissance Orbiter is busy snapping high resolution images of planet’s surface. In the winter the dunes shown here in Proctor Crater are covered with seasonal carbon dioxide frost (dry ice). In the spring, the frost gradually evaporates but lingers in protected regions. In this color image bright ice deposits in sheltered areas highlight the ripples on the dunes. Now that MRO has been in orbit for two Martian winters, this image of Proctor Crater can be compared with the images of these dunes that were taken during the first year of MRO’s mission. Scientists are comparing the images to study inter-annual variability. See an image from January 2007 of Proctor Crater below, as well as more new images from HiRISE.

Proctor Crater dune field, 2007. Credit: NASA/JPL/U of AZ
Proctor Crater dune field, 2007. Credit: NASA/JPL/U of AZ

Here’s how Proctor Crater looked two years ago (one Martian late winter ago), in January 2007. The crater is located -47.2 degrees latitude, and 33.9 degrees longitude East.
South pole CO2. Credit: NASA/JPL/U of AZ
South pole CO2. Credit: NASA/JPL/U of AZ

Every southern winter the south polar region of Mars is covered with an approximately 1 meter deep layer of frozen carbon dioxide (dry ice). In the spring, when the sun begins to warm the surface below the translucent ice, gas flow under the ice carries loose dust from the surface up onto the top.

The dust falls to the surface in fans, whose orientation is determined by the direction of the local wind flow. Fans from one source region pointing in multiple directions show how the wind direction has changed. Narrow fans pointing in just one direction are the most recent. Alternatively, the vent from the surface may have re-annealed, such that these fans were formed over a very limited time span.

Hellas Basin. Credit: NASA/JPL/U of AZ
Hellas Basin. Credit: NASA/JPL/U of AZ

Not quite so far south, at just -28.4 degrees latitude, is Hellas Basin. The detail of this image is amazing, and even though its not a 3-D image, it almost appears so, because of the depth of the detail.

This image shows part of the floor of an impact crater on the northern rim of the giant Hellas Basin.

Hellas includes the lowest elevations on Mars, and may have once held lakes or seas; layered rock outcrops occur around much of the edge of the basin. At this site, a large impact crater (about 90 kilometers across) was partly filled by layered rocks. These rocks on the crater floor are now eroding and forming strange pits.

Here, the layers are mostly exposed on a steep slope which cuts across much of the image. On this slope, they crop out as rocky stripes, some continuous and others not. The material between the stripes is mostly covered by debris, but some areas of exposed rock are visible. The slope is capped by a thick, continuous layer that armors it against erosion; once this cap is gone, the lower material is removed rapidly, forming the steep slope. At the base of this slope, rocks on the floor of the pit appear bright and heavily fragmented by cracks known as joints.

Great images — keep ’em coming, HiRISE!

For more info see the HiRISE site.

Posted on by Ian O'Neill

Has Liquid Water Been Detected On Mars?

Growing water droplets on Phoenix's legs? (NASA)

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Liquid water may have been discovered by the late Phoenix Mars Lander. This astonishing (and controversial) claim comes from some very intriguing images of the lander’s leg shortly after Phoenix landed on the Red Planet last year. The series of black and white images appear to show droplets of water hanging off the robot’s bodywork in the shade; it seems possible that the water droplets were splashed from the surface during Phoenix’s rocket-assisted landing. Far from being static blobs, they appear to grow, much like water droplets here on Earth as water vapour is absorbed from the atmosphere.

But wait a minute, isn’t the Martian atmosphere too thin and too cold to accommodate liquid water? That’s where the perchlorate comes in…

If liquid water has been found to exist on the surface of Mars, there will be huge implications for our understanding of the planet. Most tantalizingly, liquid water, on or near the planet’s surface, could aid the survival of microbial life, reinvigorating the search for extraterrestrial life on out interplanetary neighbour. But on a planet where the atmospheric pressure is 100 times less than on Earth, and temperatures reached a maximum of -20° Celcius during the Phoenix mission, why isn’t this “liquid water” candidate frozen?

The perchlorate discovery in the Martian soil was announced by the Phoenix team in August 2008, after an explosion of intense Internet conjecture caused by the “potential for life” announcement by an Aviation Week article days earlier. It turned out that the Phoenix instrumentation had found quantities of a toxic chemical called perchlorate known to be a hindrance to life as we know it. Although follow-up reports were slightly more positive about the presence of the chemical (a possible energy source for microbial life), the mood was fairly sombre. On a planet as unforgiving as Mars, any bad news is a severe knock for the hope of finding life.

However, regardless of perchlorate’s toxic effects on life, it may be helping out another one of life’s resources to stay in liquid form. If perchlorate is dissolved in significant quantities, water could remain as a liquid down to temperatures as low as -70°C. So could it be that the dissolved perchlorate salt is acting as a very impressive anti-freeze?

Nilton Renno from the University of Michigan and Phoenix team member, thinks it could be. “According to my calculations, you can have liquid saline solutions just below the surface almost anywhere on Mars,” he said.

Renno’s team carried out a series of laboratory experiments and found that the lander’s thrusters would have melted the top millimetre of ice in the regolith. The resulting water droplets may have been splashed onto the landers leg. If the concentration of perchlorate was high enough, the water could have remained in a liquid state during the Mars daytime. As time progressed, atmospheric water vapour may have been absorbed, hence the growing and shifting blobs of liquid on the leg. There is also the possibility that the droplets were splashed from pools of perchlorate-rich water already in a liquid state on the surface.

However, not everyone is convinced. Fellow Phoenix team member Michael Hecht from NASA’s Jet Propulsion Laboratory in Pasadena, California, thinks that the photographs actually show water ice, not liquid water. The “frost” changed shape as vapour from the air coalesced and froze to the leg. Renno points out that this is unlikely as any ice on the leg would be more likely to sublime, rather than grow, but Hecht believes this could happen if the leg was colder than its surroundings.

Renno’s team will be continuing tests on samples of perchlorate-rich water under Mars-like conditions for the next few months to understand the dynamics of water under these extreme conditions. What makes this even more interesting is that some microbial life on Earth has the ability to survive in very salty fluids, perhaps microbial alien life on Mars evolved in a similar environment where there were pools of liquid water maintained at extremely low temperatures by high concentrations of perchlorate salt…

Source: New Scientist

Posted on by Nancy Atkinson

Could Living Organisms Be Hiding Inside Olympus Mons?

Color mosaic of Mars' greatest mountain, Olympus Mons, viewed from orbit. Credit NASA/JPL

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From orbit, Olympus Mons dominates the landscape of the Tharsis region on Mars. At 24 kilometers (15 miles) high, and 550 kilometers (340 miles) in diameter, the huge volcano is over three times larger than Mount Everest. But Olympus Mons has a structure that is somewhat lopsided: it is elongated to the northwest, shortened to the southeast. A new study reveals that the ‘lopsidedness’ may mean warm magma and possibly water could be close enough to Olympus Mons’ surface to support thermophilic (heat-loving) bacteria like those found near hydrothermal vents on Earth.

While no volcanic activity has ever been seen or detected in Olympus Mons by orbiting spacecraft, the surface of the northwestern scarp has been dated from 115 million years old down to a region that is only 2 million years old. This is very recent in geological terms, suggesting that the mountain may yet have some ongoing volcanic activity.

To try and understand why Olympus Mons in lopsided, researchers Patrick J. McGovern and Julia K. Morgan from the Lunar and Planetary Institute, Universities Space Research Association, constructed detailed computer simulations of the volcano. They found the only way it could have the shape it does is if, when it was actively erupting, lava piled on top of layers of weak, water-laden clay sediments.

These layers could be hiding a trapped reservoir of water, if indeed Mars was once warmer and wetter. Whether that reservoir could still be warm, and if it could possibly hold life life remains uncertain. As of now, no orbiting satellites have any instruments that can penetrate the surface to look for a heat source.

This research was published in February 2009 in the journal Geology.

Source: The Geological Society of America

Posted on by Anne Minard

New Theory: Bizarre Martian Deposits from Vast Ice at Equator

Ice core from Mars? Not quite. But this aggregation of soil grains, from Antarctica ice, derived from the same process now proposed for the Red Planet (Credit: Hans Paerl, University of North Carolina at Chapel Hill).

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Ice core from Mars? Not quite. But this aggregation of soil grains, from Antarctica ice, derived from the same process now proposed for the Red Planet (Credit: Hans Paerl, University of North Carolina at Chapel Hill)

The puzzling Meridiani Planum deposits on Mars — discovered by NASA’s Opportunity rover — could be remnants of a massive ancient ice field, according to a new study online in Nature Geoscience.

Paul Niles of NASA’s Johnson Space Center and Joseph Michalski, of Université Paris-Sud, analysed the chemistry, sedimentology and geology of the Meridiani Planum deposits using data from Opportunity. They suggest that sulphate formation and chemical weathering occurred within an ice deposit as massive as today’s polar ice caps on Mars. Once the ice sublimed away in a warmer climate, the remaining sediments kept their chemical signature, the authors suggest.

The new theory gets around a weakness in the previous belief, that the deposits were formed in a wet, shallow basin — because no evidence of such a basin has been found yet. But it comes with its own baggage: there’s not much evidence of massive ice in the region, either.

The Meridiani represent one of the flattest areas on the Martian surface, with long, rolling smooth plains, linear dunes and ridges. Based on the number of craters, scientists have speculated that it formed early in the Hesperian Era, roughly 3.8 billion years ago.

The intriguing place — right at the crosshairs of zero degrees longitude and zero degrees latitude — was initially spotted by the Mars Thermal Emission Spectrometer aboard NASA’s Mars Global Surveyor (1996-2006). It was then chosen as the landing site for NASA’s rover Opportunity, in 2004.

“Immediately upon touchdown, when we turned on the cameras for the first time and looked out on the plains, it became obvious that it was a different kind of place on Mars than we’d ever been before,” Michalski said.

Since then, the place has been the object of numerous chemistry studies which have generated a handful of competing theories about how its odd sulfate deposits might have formed. The prevailing theory, fronted by scientists on the Mars Exploration Rovers team, has it that the Meridiani Planum was once a shallow evaporation basin which was periodically wet, where wind helped drive away the moisture and left the deposits behind. Other scientists have proposed a catastrophic event like a volcano or major impact, perhaps with volcanic aerosols altering layered rocks at the surface.

Microscopic image of Meridiani Planum sediments. Image of outcrop of sediments at Meridiani Planum inside Endurance crater taken by the microscopic imager on sol 145 (Credit: NASA/JPL/Cornell/USGS).
Microscopic image of Meridiani Planum sediments. Image of outcrop of sediments at Meridiani Planum inside Endurance crater taken by the microscopic imager on sol 145 (Credit: NASA/JPL/Cornell/USGS).

But Michalski and Niles say the deposits formed when the area was covered with thick ice. Dust trapped within the ice would have warmed in the presence of sunlight, causing minor melting nearby. And because the ice also contained volcanic aerosols, the water that formed would have been highly acidic, and reacted with the dust, yielding the perplexing products in pockets within the ice that became the deposits when the ice sublimed. The same process happens to a limited extent in the Earth’s polar regions, Michalski said. The Meridiani Planum is near the equator, where large ice fields are lacking today. The authors propose that the ice could have formed in ancient times, when the poles were in a different place or when the Martian axis of rotation was at a different angle.

Michalski said the new theory gets around a lot of the sticking points in the older ones.

“It doesn’t require a basin to be present; it doesn’t require the groundwater,” he said. “We like a lot of aspects of the MER team’s hypothesis. One of the big problems is that you have to have a lot of acidic water in that situation.”

Brian Hynek, an atmospheric and space physicist at the University of Colorado in Boulder, had proposed a volcanic origin for the deposits in the past, but he said there are strengths to the new theory as well. For starters, he said, the ice pocket hypothesis could explain why salts of varying water solubility co-exist so closely in the Meridiani Planum deposits.

“The volume of the Meridiani deposits is similar to the amount of sediment contained within the layered ice-rich deposits at Mars’s south pole,” he added. “And sublimation of a sufficiently large dusty ice deposit would provide a convincing source for all the sediment, which other models have failed to provide.”

But he said there are shortfalls to the new theory too: No model has allowed for the necessarily massive ice deposits at the Martian equator, for example, and it’s curious how the dust and aerosols “could aggregate into consistent sand-sized particles” in the examined bedrock.

Hynek said of all the theories that could explain the strange deposits in the Meridiani Planum, none has emerged yet as a clear winner: “All have their strengths and all have significant weaknesses. I don’t think we’ve solved this mystery yet.”

Michalski is less cautious about the implications of the new work.

“We’re able to propose this process for the Meridiani deposits because there are a lot of data,” he said. “We think that it’s likely that the other sulfate deposits on Mars could have been formed by the same mechanism.”

Sources: Joseph Michalski and Brian Hynek

Posted on by Nancy Atkinson

More Ancient Hot Springs Discovered on Mars?

Arabia Terra, a possible MSL landing site on Mars. Credit: NASA/JPL/HiRISE team

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In March 2007, the Spirit rover found a patch of bright-colored soil rich in silica. Scientists proposed water must have been involved in creating the region, and not just water, but hot water. Now, data from retrieved from the Mars Reconnaissance Orbiter (MRO) suggest the discovery of another ancient hot springs region in Vernal Crater in Arabia Terra, an area in the northern hemisphere of Mars that is densely cratered and heavily eroded. The research team says the striking similarities between these features on Mars and hot springs found on Earth provide evidence of an ancient Martian hot-spring environment. On Earth these environments teem with microbial life.

If life forms have ever been present on Mars, hot spring deposits would be ideal locations to search for physical or chemical evidence of these organisms and could be target areas for future exploratory missions such as the Mars Science Labortory. Arabia Terra is currently on the list of possible landing sites for MSL.

In their research paper “A Case for Ancient Springs in Arabia Terra, Mars,” Carlton C. Allen and Dorothy Z. Oehler, from the Astromaterials Research and Exploration Science Directorate at the NASA Johnson Space Center, Houston, Texas, propose that new image data from the HiRISE (High Resolution Imaging Science Experiment) camera on MRO show structures in Vernal Crater that appear to be the product of ancient spring activity. The data suggest that the southern part of Vernal Crater has experienced episodes of water flow from underground to the surface and may be a site where Martian life could have developed.

Vernal Crater is a 55-km diameter crater located at 6°N, 355.5°E, in the southwestern part of Arabia Terra. From orbital images, the crater appears to have layered sediments, and potentially, remnants of activity from water.

THEMIS image A. Credit: Allen and Oehler
THEMIS image A. Credit: Allen and Oehler

One feature that is bright in both daytime and nighttime in THEMIS infrared images is prominent in the southern part of Vernal crater. In this image, marked A, the feature appears dark, as the THEMIS grayscale was inverted to resemble HiRISE images in the visible range. The feature is 3 km wide and is composed of alternating light-toned and dark-toned subunits, which the researchers interpret as cemented, resistant dunes,and water-laid deposits.

The research team compares this and other structures in the region with hot springs regions on Earth, using Google Earth. The similarities of the features on Mars and Earth, the researchers say, provides a strong case that the Vernal Crater structures are relics of ancient Martian springs.

Regional view of outcrops. CTX image P04_002456_1858. Credit: Allen and Oehlers
Regional view of aligned outcrops. CTX image P04_002456_1858. Credit: Allen and Oehlers

The team says their results are consistent with the growing body of orbital and rover data that is suggestive of widespread hydrothermal activity and possible spring deposits elsewhere on Mars.

“If clays or chemical precipitates such as evaporates or silica comprise the terraced structures or tonal anomalies, signatures of that life may be preserved in those minerals,” write the research team in their paper. “The fact that several other potential spring deposits occur on-trend with Vernal structures suggests that this may have been a significant province of long-lasting spring activity.”

Source: Paper: “A Case for Ancient Springs in Arabia Terra, Mars,” by Carlton C. Allen and Dorothy Z. Oehler.

Posted on by Nancy Atkinson

Cleaning Event Boosts Spirit’s Power Levels; Oppy Back on the Road

Spirit's solar panels show a marked difference between Sol 1811 (Feb 5 - left) and Sol 1813 (Feb 7 - right). Images: NASA/JPL, collage, N.Atkinson

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Great news about the both Mars Exploration Rovers! Spirit’s dusty solar panels have been cleaned by a wind event, and Opportunity is back driving again after standing down a few days after a charged particle hit. Sprit’s solar arrays have been extremely dusty ever since a huge dust storm last year enveloped much of Mars, but a dust devil or gust of wind on Sol 1812 (Feb. 6, 2009 here on Earth) has cleaned the panels just enough to make a marked difference in power available to the intrepid rover. Before the event, dust buildup on the arrays had reached the point where only 25 percent of sunlight hitting the array was getting past the dust to be used by the photovoltaic cells. Now, it is up to 28 percent. “It may not sound like a lot, but it is an important increase,” said Jennifer Herman, and engineer for the MER team.

The cleaning boosts Spirit’s daily energy supply by about 30 watt-hours, to about 240 watt-hours from 210 watt-hours. The rover uses about 180 watt-hours per day for basic survival and communications, so this increase roughly doubles the amount of discretionary power for activities such as driving and using instruments. Thirty watt-hours is the amount of energy used to light a 30-watt bulb for one hour.

“We will be able to use this energy to do significantly more driving,” said Colette Lohr, a rover mission manager at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Our drives have been averaging about 50 minutes, and energy has usually been the limiting factor. We may be able to increase that to drives of an hour and a half.”

Spirit has driven about 9 meters (about 30 feet) since getting around a rock that temporarily blocked its progress on Jan. 31. The team’s goal in coming weeks is to navigate the rover over or around a low plateau called “Home Plate” to get to an area targeted for scientific studies on the other side of Home Plate in Gusev Crater.

The last prior cleaning event that was as beneficial as this one was in June 2007. Winds cleaned off more of the dust that time, but a dust storm in subsequent weeks undid much of the benefit.

Opportunity's tracks through the dunes on Mars, on Sol 1791 (Feb 5). Credit: NASA/JPL
Opportunity's tracks through the dunes on Mars, on Sol 1791 (Feb 5). Credit: NASA/JPL


Over on the other side of the planet in Meridiani Planum, Opportunity, drove 135.9 meters (446 feet) on Feb. 10. Opportunity stood down for a few sols as a result of a PMA (Panoramic Mast Assembly) error, due to a SEU (Single-Event Upset), when a charged particle whizzes through a transistor on the rover and flips a bit somewhere inside. “Fortunately, the motor controllers can detect and report these events, so that the rover can safely stop,” rover driver Scott Maxwell told Universe Today on February 5. “We have good reason to hope that Opportunity’s PMA is undamaged and that she’ll be back on the road shortly.”

And now she is back driving to her little heart’s (and the rover drivers’ hearts) content. Opportunity’s cumulative odometry is 14.36 kilometers (8.92 miles) since landing in January 2004, including 2.58 kilometers (1.6 miles) since climbing out of Victoria Crater on Aug. 28, 2008. She is on her way to Endeavour Crater, a huge crater about about 12 kilometers (7 miles) away.

The rovers have been taking a licking, but they still keep on ticking! Over five years now for both rovers –Yippee!

Source: JPL