Category: Mars

Since landing on Mars a year ago, NASA’s pair of six-wheeled geologists have been constantly exposed to martian winds and dust. Because the rovers use solar power and sunlight is currently limited on Mars, the rovers can only cover from 50 to 100 feet on a good day. The sunlight is seasonal and also power-limiting as the rover’s age and get covered by dust. Among the failure models for eventually retiring the rovers, an electronic glitch or dust accumulation are most likely than a mechanical breakage.

Both rovers have been coated by some dust falling out of the atmosphere during that time, with estimates of the dust thickness ranging from 1 to 10 micrometers, or between 1/100th and 1/10th the width of a single human hair.

Of the two, NASA’s Mars Exploration Rover Spirit is definitely the more dust-laden. The Opportunity rover appears to be collecting less dust, perhaps because of a cleaning by wind or even “scavenging” of dust by frost that forms on the rover some nights during the martian winter. In imagining the texture of the rocks found by the Opportunity rover, the mission team has compared them to spongy sandstone. They are pockmarked, porous, dried and cracked. The voids and holes in these spongy rocks may have arisen from repeated cycles of evaporation to harden the surfaces followed by a washing away to dissolve the more soluble interior portions.

NASA’s Mars Exploration Rover Spirit is definitely the more dust-laden. As a result, Spirit has gradually experienced a decline in power as the thin layer of dust has accumulated on the solar panels, blocking some of the sunlight that is converted to electricity. The panoramic camera team’s analysis indicates that the layer of dust on Spirit’s calibration target is about 70 percent thicker than that on Opportunity’s.

Prior to this mission, the Meridiani plains were compared to the Rust Belt states, those in the middle north of America (Michigan, Ohio, Pennsylvania). The other comparison was to the red dirt found in Oklahoma and northern Texas–the so-called Red River region. In addition to red dirt, the rovers have found bedrock. On earth, bedrock is common in northern New England, particularly Maine and New Hampshire, the Granite state. But the wind blows around enough dry dust on Mars to cover what might be exposed bedrock. This debris layer blankets most of the rest of the planet. Additionally, meteors have pulverized the martian surface leaving a thick crushed layer.

A portion of Mars’ water vapor is moving from the north pole toward the south pole during the current northern-summer and southern-winter period. The transient increase in atmospheric water at Meridiani, just south of the equator, plus low temperatures near the surface, contribute to appearance of the clouds and frost. Frost shows up some mornings on the rover itself. The possibility that it has a clumping effect on the accumulated dust on solar panels is under consideration as a factor in unexpected boosts of electric output from the panels.

The atmosphere of Mars contains water, but in miniscule amounts. “Even though we are currently seeing frequent clouds with Opportunity, if you squeezed all of the water out of the atmosphere, it would only be less than 100 microns deep, about the thickness of a human hair,” said Mark Lemmon of Texas A&M University’s College of Geosciences.

Because of the lack of water, weather on Mars has a lot to do with dust in the atmosphere. A small dust storm one month before the rovers landed spread small amounts of dust around the planet.

“Both rovers saw very dusty skies at first. It was only after the dust settled after a few months that Spirit could see the rim of the crater it was in, Gusev Crater, about 40 miles away,” Lemmon said.

British scientists have speculated that the British Mars Lander, Beagle 2, crashed because the atmosphere was thinner than usual as a result of heating caused by atmospheric dust from the December storm.

“I can think of at least three things could kill us,” said Cornell’s principal investigator for the Mars rovers, Steve Squyres, when discussing the mission lifetime with the Astrobiology Magazine. “The first is dust build-up on the solar arrays. But the dust build-up is not that bad, especially for Opportunity, and with spring approaching both vehicles should do ok for awhile.”

“The second thing is if something mechanical goes wrong,” said Squyres. “The rovers have a lot of moving parts, and we’ve seen a few mechanical funnies on Spirit. Nothing serious, but enough to catch your attention. Stuff could just wear out.”

“The third thing is, we’ve got a lot of single-string electronics in these vehicles,” said Squyres. “There’s not a lot of redundancy. Now, we have the ultimate redundancy in that there are two vehicles. But within each rover there are a lot of electrical parts that, if they just flat-out fail on us, the rover’s dead. Bang! It just dies overnight and never talks to us again. That could happen.”

Original Source: NASA Astrobiology Magazine

Imagine this scenario. The year is 2030 or thereabouts. After voyaging six months from Earth, you and several other astronauts are the first humans on Mars. You’re standing on an alien world, dusty red dirt beneath your feet, looking around at a bunch of mining equipment deposited by previous robotic landers.

Echoing in your ears are the final words from mission control: “Your mission, should you care to accept it, is to return to Earth–if possible using fuel and oxygen you mine from the sands of Mars. Good luck!”

It sounds simple enough, mining raw materials from a rocky, sandy planet. We do it here on Earth, why not on Mars, too? But it’s not as simple as it sounds. Nothing about granular physics ever is.

Granular physics is the science of grains, everything from kernels of corn to grains of sand to grounds of coffee. These are common everyday substances, but they can be vexingly difficult to predict. One moment they behave like solids, the next like liquids. Consider a dump truck full of gravel. When the truck begins to tilt, the gravel remains in a solid pile, until at a certain angle it suddenly becomes a thundering river of rock.

Understanding granular physics is essential for designing industrial machinery to handle vast quantities of small solids–like fine Martian sand.

The problem is, even here on Earth “industrial plants don’t work very well because we don’t understand equations for granular materials as well as we understand the equations for liquids and gases,” says James T. Jenkins, professor of theoretical and applied mechanics at Cornell University in Ithaca, N.Y. “That’s why coal-fired power plants operate at low efficiencies and have higher failure rates compared to liquid-fuel or gas-fired power plants.”

So “do we understand granular processing well enough to do it on Mars?” he asks.

Let’s start with excavation: “If you dig a trench on Mars, how steep can the sides be and remain stable without caving in?” wonders Stein Sture, professor of civil, environmental, and architectural engineering and associate dean at the University of Colorado in Boulder. There’s no definite answer, not yet. The layering of dusty soils and rock on Mars isn’t well enough known.

Some information about the mechanical composition of the top meter or so of Martian soils could be gained by ground-penetrating radar or other sounding devices, Sture points out, but much deeper and you “probably need to take core samples.” NASA’s Phoenix Mars lander (landing 2008) will be able to dig trenches about a half-meter deep; the 2009 Mars Science Laboratory will be able to cut out rock cores. Both missions will provide valuable new data.

To go even deeper, Sture (in connection with the University of Colorado’s Center for Space Construction) is developing innovative diggers whose business ends vibrate into soils. Agitation helps break cohesive bonds holding compacted soils together and can also help mitigate the risk of soils collapsing. Machines like these might one day go to Mars, too.

Another problem is “hoppers”–the funnels miners use to guide sand and gravel onto conveyor belts for processing. Knowledge of Martian soils would be vital in designing the most efficient and maintenance-free hoppers. “We don’t understand why hoppers jam,” Jenkins says. Jams are so frequent, in fact, that “on Earth, every hopper has a hammer close by.” Banging on the hopper frees the jam. On Mars, where there would be only a few people around to tend equipment, you’d want hoppers to work better than that. Jenkins and colleagues are researching why granular flows jam.

And then there’s transportation: The Mars rovers Spirit and Opportunity have had little trouble driving miles around their landing sites since 2004. But these rovers are only about the size of an average office desk and only about as massive as an adult. They’re go-carts compared to the massive vehicles possibly needed for transporting tons of Martian sand and rock. Bigger vehicles are going to have a tougher time getting around.

Sture explains: As early as the 1960s when scientists were first studying possible solar-powered rovers for negotiating loose sands on the Moon and other planets, they calculated “that the maximum viable continuous pressure for rolling contact pressure over Martian soils is only 0.2 pounds per square inch (psi),” especially when traveling up or down slopes. This low figure has been confirmed by the behavior of Spirit and Opportunity.

A rolling contact pressure of only 0.2 psi “means that a vehicle has to be light-weight or has to have a way of effectively distributing the load to many wheels or tracks. Reducing contact pressure is crucial so the wheels don’t dig into soft soil or break through duricrusts [thin sheets of cemented soils, like the thin crust on windblown snow on Earth] and get stuck.”

That requirement implies that a vehicle for moving heavier loads–people, habitats, equipment–might be “a huge Fellini-type thing with wheels 4 to 6 meters (12 to 18 feet) in diameter,” says Sture, referring to the famous Italian director of surreal films. Or it might have enormous open-mesh metal treads like a cross between highway-construction backhoes on Earth and the lunar rover used during the Apollo program on the Moon. Thus, tracked or belted vehicles seem promising for carrying large payloads.

A final challenge facing granular physicists is to figure out how to keep equipment operating through Mars’ seasonal dust storms. Martian storms whip fine dust through the air at velocities of 50 m/s (100+ mph), scouring every exposed surface, sifting into every crevice, burying exposed structures both natural and manmade, and reducing visibility to meters or less. Jenkins and other investigators are studying the physics of aeolian [wind] transporting of sand and dust on Earth, both to understand the formation and moving of dunes on Mars, and also to ascertain what sites for eventual habitats might be best protected from prevailing winds (for example, in the lee of large rocks).

Returning to Jenkins’s big question, “do we understand granular processing well enough to do it on Mars?” The unsettling answer is: we don’t yet know.

Working with imperfect knowledge is okay on Earth because, usually, no one suffers much from that ignorance. But on Mars, ignorance could mean reduced efficiency or worse preventing the astronauts from mining enough oxygen and hydrogen to breathe or use for fuel to return to Earth.

Granular physicists analyzing data from the Mars rovers, building new digging machines, tinkering with equations, are doing their level best to find the answers. It’s all part of NASA’s strategy to learn how to get to Mars … and back again.

Original Source: Science@NASA

Image credit: ESA
The SPICAM instrument on board ESA?s Mars Express has detected light emissions over the nightside of Mars caused by the production of nitrogen oxide in the atmosphere.

SPICAM is a dual ultraviolet/infrared spectrometer dedicated primarily to the study of the atmosphere and ionosphere of Mars. Spectroscopy of ?airglow? and radiometry are powerful methods for remote sensing investigations of the physics of upper atmospheres of the terrestrial planets.

For instance, Martian ?dayglow? spectra reveal the effect of extreme ultraviolet radiation from the Sun on carbon dioxide in Mars?s upper atmosphere, and show it to be a major heating mechanism and involved in the production of an ionosphere.

?Dayglow? and ?nightglow? effects are emissions of light in the upper atmosphere which are produced when atoms combine to form molecules, releasing energy in the form of photons. Dayglow is visible in the dayside upper atmosphere, and nightglow over the nightside.

The ultraviolet spectrum of the nightglow seen by SPICAM is produced when nitrogen and oxygen atoms combine to produce nitrogen oxide molecules (?recombination?) and release energy.

A similar ultraviolet nightglow on Venus had been detected with Mariner 5 and Pioneer Venus, but the first real evidence for this process was a spectrum acquired with the ESA/NASA International Ultraviolet Explorer satellite which identified the nightglow emissions as coming from nitrogen oxide recombination.

Scientists proposed that nitrogen and oxygen atoms are produced on the Venus day side by a process called ?electron ultraviolet photodissociation?. This is the break-up of oxygen, nitrogen and carbon dioxide molecules by ultraviolet light. The separate atoms were then transported to the nightside where recombination occurs.

These findings were later supported by detailed Pioneer Venus spectra and computer modelling of Venusian atmospheric circulation. Until now, however, this kind of nightglow had never been seen on Mars. It is thought that the mechanism responsible for the nightglow emissions on Mars is the same as that causing the nightglow on Venus.

These nightglow emissions are important tracers of atmospheric transport at high altitudes, which could be used in refining circulation models of the Martian atmosphere.

Original Source: ESA News Release

NASA’s Mars Exploration Rover Opportunity has found an iron meteorite, the first meteorite of any type ever identified on another planet.

The pitted, basketball-size object is mostly made of iron and nickel according to readings from spectrometers on the rover. Only a small fraction of the meteorites fallen on Earth are similarly metal-rich. Others are rockier. As an example, the meteorite that blasted the famous Meteor Crater in Arizona is similar in composition.

“This is a huge surprise, though maybe it shouldn’t have been,” said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the science instruments on Opportunity and its twin, Spirit.

The meteorite, dubbed “Heat Shield Rock,” sits near debris of Opportunity’s heat shield on the surface of Meridiani Planum, a cratered flatland that has been Opportunity’s home since the robot landed on Mars nearly one year ago.

“I never thought we would get to use our instruments on a rock from someplace other than Mars,” Squyres said. “Think about where an iron meteorite comes from: a destroyed planet or planetesimal that was big enough to differentiate into a metallic core and a rocky mantle.”

Rover-team scientists are wondering whether some rocks that Opportunity has seen atop the ground surface are rocky meteorites. “Mars should be hit by a lot more rocky meteorites than iron meteorites,” Squyres said. “We’ve been seeing lots of cobbles out on the plains, and this raises the possibility that some of them may in fact be meteorites. We may be investigating some of those in coming weeks. The key is not what we’ll learn about meteorites — we have lots of meteorites on Earth — but what the meteorites can tell us about Meridiani Planum.”

The numbers of exposed meteorites could be an indication of whether the plain is gradually eroding away or being built up.

NASA Chief Scientist Dr. Jim Garvin said, “Exploring meteorites is a vital part of NASA’s scientific agenda, and discovering whether there are storehouses of them on Mars opens new research possibilities, including further incentives for robotic and then human-based sample-return missions. Mars continues to provide unexpected science ‘gold,’ and our rovers have proven the value of mobile exploration with this latest finding.”

Initial observation of Heat Shield Rock from a distance with Opportunity’s miniature thermal emission spectrometer suggested a metallic composition and raised speculation last week that it was a meteorite. The rover drove close enough to use its Moessbauer and alpha particle X-ray spectrometers, confirming the meteorite identification over the weekend.

Opportunity and Spirit successfully completed their primary three-month missions on Mars in April 2004. NASA has extended their missions twice because the rovers have remained in good condition to continue exploring Mars longer than anticipated. They have found geological evidence of past wet environmental conditions that might have been hospitable to life.

Opportunity has driven a total of 2.10 kilometers (1.30 miles). Minor mottling from dust has appeared in images from the rover’s rear hazard-identification camera since Opportunity entered the area of its heat-shield debris, said Jim Erickson of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., rover project manager. The rover team plans to begin driving Opportunity south toward a circular feature called “Vostok” within about a week.

Spirit has driven a total of 4.05 kilometers (2.52 miles). It has been making slow progress uphill toward a ridge on “Husband Hill” inside Gusev Crater.

JPL, a division of the California Institute of Technology in Pasadena, has managed NASA’s Mars Exploration Rover project since it began in 2000. Images and additional information about the rovers and their discoveries are available on the Internet at http://www.nasa.gov/vision/universe/solarsystem/mer_main.html and at http://marsrovers.jpl.nasa.gov.

Original Source: NASA/JPL News Release

This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA?s Mars Express spacecraft, shows Claritas Fossae, a series of linear fractures located in the Tharsis region of Mars.

The HRSC obtained this image during orbit 563, with a resolution of approximately 62 metres per pixel. The image shows a region centred around latitude 25? South and longitude 253? East.

Claritas Fossae is located on the Tharsis rise, south of the three large volcanoes known as the Tharsis Montes, and extends roughly north to south for approximately 1800 kilometres. The linear fractures of Claritas Fossae have widths ranging from a few kilometres to 100 kilometres, and the region is about 150 kilometres wide in the north and 550 kilometres wide in the south.

These fractures are radial to the Tharsis rise, consistent with the idea that they are the result of enormous stresses associated with formation of the 8-10 kilometre high Tharsis rise. Faults running east to west are also visible in the colour image and may have a similar origin.

In the east of the colour image, a prominent linear feature with a dark shadow is visible. This is most likely a normal fault, the eastern edge of a 100 kilometre wide ?graben?. A graben is a block of Mars’s crust which has dropped down due to an extension, or pulling, of the crust. This graben is characterised by a smooth surface and the difference in height between the edge of the graben and the plains east of the normal fault is roughly 2.3 kilometres. Alternatively, this feature may have resulted from surface collapse due to magma withdrawal.

The smooth surfaces in the image suggest this terrain has been resurfaced by lava flows. The observation that the lava flows have covered some of these faults, particularly in the west and north-east of the image, suggests that Claritas Fossae is older than the surrounding terrain.

The outline of a crater with a diameter of 50 kilometres is visible in the centre of the image. The softened appearance of the crater, and especially the observation that fractures extend across the crater, suggest this crater pre-dates the formation of the fractures. South of this crater, a faint outline is visible with a diameter of 70 kilometres, which may be another ancient crater.

West of these two craters, there is a small region with an interesting morphology, shown in the close-up image. These features seem to be weakly influenced by the north-south fractures. While the cause of emplacement of this terrain is still unclear, collapse of the surface due to the removal of subsurface ice might be responsible for these features.

By supplying new image data for Clarita Fossae, the HRSC camera allows improved study of the complex geology and history of the area. The stereo and colour capability of the HRSC camera provides scientists with the opportunity to better understand the Red Planet?s morphology, the evolution of rocks and landforms, and helps to pave the way for future Mars missions.

Original Source: ESA News Release

NASA lit a birthday candle today for its twin Mars Exploration Rovers, Spirit and Opportunity. The Spirit rover begins its second year on Mars investigating puzzling rocks unlike any found earlier.

The rovers successfully completed their three-month primary missions in April. They astound even their designers with how well they continue operating. The unanticipated longevity is allowing both rovers to reach additional destinations and to keep making discoveries. Spirit landed on Jan. 3 and Opportunity Jan. 24, 2004, respectively.

“You could have cut the tension here with a knife the night Spirit landed,” said NASA Administrator Sean O’Keefe. “Just remembering the uncertainty involved with the landing emphasizes how exciting it is for all of us, since the rovers are still actively exploring. The rovers created an amazing amount of public interest and have certainly helped advance the Vision for Space Exploration,” he said. The twin Mars explorers have drawn the most hits to NASA Web sites – – more than 9 billion in 2004.

Dr. Charles Elachi, director of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., said, “Little did we know a year ago that we’d be celebrating a year of roving on Mars. The success of both rovers is tribute to hundreds of talented men and women who have put their knowledge and labor into this team effort.”

“The rovers are both in amazingly good shape for their age,” said JPL’s Jim Erickson, rover project manager. “The twins sailed through the worst of the martian winter with flying colors, and spring is coming. Both rovers are in strong positions to continue exploring, but we can’t give you any guarantees.”

Opportunity is driving toward the heat shield that protected it during descent through the martian atmosphere. Rover team members hope to determine how deeply the atmospheric friction charred the protective layer. “With luck, our observations may help to improve our ability to deliver future vehicles to the surface of other planets,” Erickson said.

Spirit is exploring the Columbia Hills within the Gusev Crater. “In December, we discovered a completely new type of rock in Columbia Hills, unlike anything seen before on Mars,” said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the rovers’ science payloads.

Jumbled textures of specimens dubbed “Wishstone” and “Wishing Well” look like the product of an explosion, perhaps from a volcano or a meteor impact. These rocks are much richer in phosphorus than any other known Mars rocks. “Some ways of making phosphates involve water; others do not,” Squyres said. “We want to look at more of these rocks to see if we can distinguish between those possible histories.”

NASA’s next Mars mission, the Mars Reconnaissance Orbiter, is due to launch in August. “As great as the past year has been, Mars launch opportunities come along like clockwork every 26 months,” said Dr. Firouz Naderi of JPL, manager of NASA’s Mars Exploration Program. “At every one of them in the foreseeable future, we intend to go to Mars, building upon the findings by the rovers.”

NASA Chief Scientist Dr. Jim Garvin said, “Mars lures us to explore its mysteries. It is the most Earth-like of our sister planets, and many believe it may hold clues to whether life ever existed or even originated beyond Earth. The rovers have shown us Mars had persistently wet, possibly life-sustaining environments. Beyond their own profound discoveries, the rovers have advanced our step-by- step program for examining Mars. We will continue to explore Mars robotically, and eventually with human explorers.”

Images and additional information about the rovers and their discoveries are available on the Internet at http://www.nasa.gov/vision/universe/solarsystem/mer_main.html and http://marsrovers.jpl.nasa.gov/home/index.html.

JPL has managed the Mars Exploration Rover project since it began in 2000. JPL is a division of the California Institute of Technology in Pasadena.

Original Source: NASA/JPL News Release

After six fruitful months exploring the interior of “Endurance Crater,” the Opportunity rover has successfully climbed out of the crater onto the surrounding flatland of Meridiani Planum. Once out, the rover examined some of its own tracks that it had laid down prior to entering the crater. It compared them side-by-side with fresh tracks in order to observe any weathering effects in the intervening 200 sols. Opportunity is now making its way toward an engineering examination of its heat shield, which is located about 200 meters (220 yards) from the edge of Endurance. Now that the vehicle is on the relatively flat plain rather than tilted toward the Sun on the north-facing inner slope of the crater, electrical output from its solar array has declined by about 15 percent. Opportunity remains in excellent health as it begins a new phase of exploration.

Sol 312 and 313 were planned in a single planning cycle. Opportunity was still inside Endurance Crater. On sol 312 the plan began with backing up and using the panoramic camera and miniature thermal emission spectrometer to observe a rock target called “Wharenhui,” which had been treated with the rock abrasion tool on earlier sols. Subsequent commands were to turn cross-slope, drive 7 meters (23 feet), turn upslope, and drive an additional 6 meters (20 feet) uphill. Opportunity performed the drive perfectly, ending up approximately 5 meters (16.4 feet) from the rim of Endurance Crater. Opportunity’s tilt went from 25 degrees pre-drive to 19 degrees post-drive.

Sol 313 was a restricted sol because results from the sol 312 drive were not available for planning sol 313. That meant that no driving or robotic-arm activities were permitted. So Opportunity performed about two hours of observations using the panoramic camera and miniature thermal emission spectrometer and then went to sleep in the early afternoon. The rover woke up to support late-afternoon and early-morning communication relays by the orbiting Mars Odyssey.

Sols 314 through 316 were planned in another single planning cycle. The plan was to complete the egress from Endurance Crater on sol 315, so sol 314 was another remote sensing sol. This would be the last full sol inside Endurance. Opportunity spent about two and a half hours observing with the panoramic camera and miniature thermal emission spectrometer. It also performed a nighttime observation with the miniature thermal emission spectrometer just before midnight. To ensure that Opportunity had adequate power, the early-morning communication-relay session with Odyssey was canceled and Opportunity went into a modified deep sleep after completing the late-night observation.

Sol 315 was the big day for Opportunity. The rover was finally going to leave Endurance Crater after spending 181 sols there! Opportunity was instructed to drive 7 meters (23 feet) up and out of the crater. It was a textbook drive. Everything went as planned and Opportunity had finally, successfully completed a long and detailed series of observations inside Endurance. Opportunity ended up on the plains of Meridiani ready to begin the next chapter of its adventures.

Sol 316 was the third sol of a three-sol plan, and because Opportunity had driven on sol 315, sol 316 was restricted to remote-sensing observations. The rover performed about two hours of remote sensing and went to sleep. Out on the plains, Opportunity went from a northerly tilt that is very good for solar exposure, to a southerly tilt that is not so good for solar exposure. The tilt was expected to be as high as 10 degrees, but Opportunity’s actual tilt was about 5 degrees. Daily output from the solar panels went from 840 watt-hours in the crater, to 730 watt-hours on the plains.

Since the team continues to be operating in restricted sol mode, sols 317 and 318 were planned together as a two-sol plan. For sol 317, the science team elected to drive toward wheel tracks that Opportunity had made before entering Endurance Crater. The rover backed up about 5 meters (16.4 feet), performed some mid-drive imaging, and then continued another 10 meters (33 feet) to put the old rover tracks into the work volume of the robotic arm. Sol 318 was another remote-sensing sol, during which Opportunity imaged its still-distant heat shield and conducted a miniature thermal emission spectrometer observation of the tracks.

After the drive, both old and new tracks were directly in front of the rover. On sol 319 Opportunity captured microscopic imager mosaics of both types of tracks, then drove about 40 meters (131 feet) closer to the heat shield, which will be examined carefully in future sols. Sol 319 ended on Dec. 17.

Original Source: NASA News Release

Image credit: ESA
This perspective view, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, shows the complex caldera of Olympus Mons on Mars, the highest volcano in our Solar System. It may also offer the best chance to find more geologically recent volcanic activity on Mars.

“We would be very lucky to see [an eruption], but it would be a massive event,” said Gerhard Neukum in USA Today. Neukum is a professor at Berlin’s Free University and lead author of a study in Nature magazine suggesting a revised timeline for lava on Mars.

While Mars is littered with collapsed volcano remnants, none have been observed as active right now. The new images indicate some of these volcanoes are merely dormant, not dead. The timeline proposed from studying the complex Olympus Mons caldera suggests there have been lava flows from intense volcanic activity within the past 2 million years.

To geologists, two million years is regarded as recent since it corresponds to the last one percent of the planet’s history.

For instance, the curved striations on the left and foreground, in the southern part of the caldera, are tectonic faults. After lava production has ceased the caldera collapsed over the emptied magma chamber. Through the collapse the surface suffers from extension and so extensional fractures are formed.

“I suspect that as we get more spacecraft in orbit that it will increase the chances of seeing some kind of active eruption,” said Dr. James W. Head III, a professor of geological sciences at Brown. As quoted in Associated Press commentary, Dr. Head is one of more than 40 scientists who contributed to analysis of the images.

The level plain inside the crater on which these fractures can be observed represents the oldest caldera collapse. Later lava production caused new caldera collapses at different locations (the other circular depressions). They have partly destroyed the circular fracture pattern of the oldest one.

This perspective view of the caldera was calculated from the digital elevation model derived from the stereo channels and combined with the nadir and color channels of the HRSC.

University of Buffalo volcanologist, Dr. Tracy Gregg, discussed the scientific appeal of studying Martian volcanoes in detail. “If both of these [Opportunity and Spirit] landers survive with airbag technology, then it blows the doors wide open for future Mars landing sites with far more interesting terrain. A landing site near a volcano might be possible, now that the airbag technology has worked so wonderfully.”

The current generation of Mars missions has adopted the theme, “Follow the Water”, as a quest to understand the complex geological history of a planet that may have had significant reserves once. For that much warmer and wetter Mars, this motto also requires other ingredients for microbial life, including primordial “fire” in the form of biological temperature ranges and potentially geothermal heat.

“I’d like to see us land ON a volcano,” said Gregg. “Right on the flanks. Often the best place to look for evidence of life on any planet is near volcanoes.”

“That may sound counterintuitive, but think about Yellowstone National Park , which really is nothing but a huge volcano,” said Gregg. “Even when the weather in Wyoming is 20 below zero, all the geysers, which are fed by volcanic heat, are swarming with bacteria and all kinds of happy little things cruising around in the water. So, since we think that the necessary ingredients for life on earth were water and heat, we are looking for the same things on Mars, and while we definitely have evidence of water there, we still are looking for a source of heat.”

While Olympus Mons is dormant today, volcanologists are not entirely convinced more isn’t going on geothermally on Mars. “If you’d asked me [if there were not active surface volcanoes] 10 years ago–or even 5–I might’ve said yes,” said Gregg. “Now I’m not so sure.”

On Mars, “where would I look for recent volcanic activity? Depends on how you want to define it on Mars,” said Gregg. “I strongly suspect there are still molten (or at least mushy) magma bodies beneath the huge Tharsis volcanoes , and beneath Elysium Mons .”

“But the youngest surficial activity discovered to date (and it’s probably 1 million years old, which would be considered quite young, and possibly ‘active’ on Mars) is in a region that contains no large volcanic structures of any kind,” said Gregg. “Instead, there are cracks in the ground, and a few low-lying volcanoes that can’t even be seen except in the high-resolution topography (they are too subtle for imagery to reveal). This area is called Cerberus Fossae .”

Seeing important events surrounding Olympus Mons is not entirely just about geology, as the famed science fiction writer, Sir Arthur C. Clarke, indicated this was the site for his own version of desktop terraforming. “Soon after maps of the real Mars became available, I received a generous gift from computer genius John Hinkley–his Vistapro image-processing system. This prompted me to do some desktop terraforming (a word, incidently, invented by science fictions’ Grandest of Grand Masters, Jack Williamson). I must confess that in ‘The Snows of Olympus: A Garden on Mars’ (1995) I frequently allowed artistic considerations to override scientific ones. Thus I couldn’t resist putting a lake in the caldera of Mount Olympus, unlikely though it is that the strenuous efforts of future colonists will produce an atmosphere dense enough to permit liquid water at such an altitude.”

Original Source: NASA Astrobiology Magazine

It would be a planetary scientist?s dream to peer through the eyes of a distant rover?s lenses in real-time, looking around an alien landscape as if she were actually on the planet?s surface, but current radio transmitters can?t handle the bandwidth necessary for a video feed across several million miles. New technology recently patented by scientists at the University of Rochester, however, may make applications like a Mars video feed possible, using lasers instead of radio technology. Special gratings inside the glass of a fiber laser virtually eliminate detrimental scattering, the main hurdle in the quest for high-powered fiber lasers.

?We use lasers in everything from telecommunications to advanced weaponry, but when we need a high-powered laser, we had to fall back on old, inefficient methods,? says Govind Agrawal, professor of optics at the University of Rochester. ?We?ve now shown an incredibly simple way to make high-power fiber lasers, which have enormous potential.?

By removing one of the main limitations of fiber lasers and fiber amplifiers, Agrawal has allowed them to replace traditionally more powerful, but less efficient and poorer quality, traditional lasers. Currently, industries use carbon dioxide and diode-pumped solid-state crystal lasers for welding or cutting metal and machining tiny parts, but these kinds of lasers are bulky and hard to cool. In contrast, the newest alternative, fiber lasers, are efficient, easy to cool, more compact, and more precise. The problem with fiber lasers, however, is that as their wattage increases, the fiber itself begins to create a backlash that effectively shuts down the laser.

Agrawal worked on a way to eliminate the backlash caused by a condition called stimulated Brillouin scattering. When light of high enough power travels down a fiber, the light itself changes the composition of the fiber. The light waves cause areas of the glass fiber to become more and less dense, much as a traveling caterpillar scrunches up and expands its body as it moves along. As the laser light passes from an area of high density to one of low density, it is diffracted the same way the image of a straw bends as it passes between the air and water in a glass. As the power of the laser increases, the diffraction increases until it is reflecting much of the laser light backward, toward the laser itself, instead of properly down the fiber.

In a discussion with, Hojoon Lee, a visiting professor from Korea, Agrawal wondered if gratings etched inside the fiber might help stop the reflection problem. The gratings can be designed to act as a kind of two-way mirror, working almost exactly the same way as the initial problem, only reflecting light forward instead of backward. With the new, simple design, the laser light fires down the fiber through the gratings, and some of it again creates the density changes that reflect some of the light backward?but this time the series of gratings simply bounces that backward reflection forward again. The net result is that the fiber laser can deliver higher wattages than ever before, rivaling conventional lasers and making possible applications that conventional lasers cannot perform, such as high-bandwidth laser communication with a planetary rover several million miles away.

As a laser beam travels between planets, it spreads out and diffracts so much that by the time a beam from Mars reaches us, its width would be larger than 500 miles, making it incredibly difficult to extract the information encoded on the beam. A fiber laser, with its ability to deliver more power, would help by giving receiving stations a more intense signal to work with. In addition, Agrawal is now working with NASA to develop a laser communications system that would spread less to begin with. ?It?s our hope that instead of having a beam that spreads out 500 miles, maybe we can get one that only spreads out a mile or so,? says Agrawal. That concentration of the laser?s power would make it much easier for us to receive high-bandwidth signals from a distant rover.

Many people are using fiber lasers to replace conventional lasers, from the military to the University of Rochester?s own Omega laser in the Laboratory for Laser Energetics (LLE), which is the most powerful ultraviolet laser in the world. Agrawal will be working with scientists at LLE to possibly implement the new grating system into the Omega?s new fiber laser system.

Original Source: University of Rochester News Release

NASA has selected eight proposals to provide instrumentation and associated science investigations for the mobile Mars Science Laboratory (MSL) rover, scheduled for launch in 2009. Proposals selected today were submitted to NASA in response to an Announcement of Opportunity (AO) released in April.

The MSL mission, part of NASA’s Mars Exploration Program, will deliver a mobile laboratory to the surface of Mars to explore a local region as a potential habitat for past or present life. MSL will operate under its own power. It is expected to remain active for one Mars year, equal to two Earth years, after landing.

In addition to the instrumentation selected, MSL will carry a pulsed neutron source and detector for measuring hydrogen (including water), provided by the Russian Federal Space Agency. The project also will include a meteorological package and an ultraviolet sensor provided by the Spanish Ministry of Education and Science.

“This mission represents a tremendous leap forward in the exploration of Mars,” said NASA’s Deputy Associate Administrator for the Science Mission Directorate, Dr. Ghassem Asrar. “MSL is the next logical step beyond the twin Spirit and Opportunity rovers. It will use a unique set of analytical tools to study the red planet for over a year and unveil the past and present conditions for habitability of Mars,” Asrar said.

“The Mars Science Laboratory is an extremely capable system, and the selected instruments will bring an analytical laboratory to the martian surface for the first time since the Viking Landers over 25 years ago,” said Douglas McCuistion, Mars Exploration Program director at NASA Headquarters.

The selected proposals will conduct preliminary design studies to focus on how the instruments can be accommodated on the mobile platform, completed and delivered consistent with the mission schedule. NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif., manages the MSL Project for the Science Mission Directorate.

Selected investigations and principal investigators:

— “Mars Science Laboratory Mast Camera,” Michael Malin, Malin Space Science Systems (MSSS), San Diego, Calif. Mast Camera will perform multi-spectral, stereo imaging at lengths ranging from kilometers to centimeters, and can acquire compressed high-definition video at 10 frames per second without the use of the rover computer.

— “ChemCam: Laser Induced Remote Sensing for Chemistry and Micro-Imaging,” Roger Wiens, Los Alamos National Laboratory, Los Alamos, N.M. ChemCam will ablate surface coatings from materials at standoff distances of up to 10 meters and measure elemental composition of underlying rocks and soils.

— “MAHLI: MArs HandLens Imager for the Mars Science Laboratory,” Kenneth Edgett, MSSS. MAHLI will image rocks, soil, frost and ice at resolutions 2.4 times better, and with a wider field of view, than the Microscopic Imager on the Mars Exploration Rovers.

— “The Alpha-Particle-X-ray-Spectrometer for Mars Science Laboratory (APXS),” Ralf Gellert, Max-Planck-Institute for Chemistry, Mainz, Germany. APXS will determine elemental abundance of rocks and soil. APXS will be provided by the Canadian Space Agency.

— “CheMin: An X-ray Diffraction/X-ray Fluorescence (XRD/XRF) instrument for definitive mineralogical analysis in the Analytical Laboratory of MSL,” David Blake, NASA’s Ames Research Center, Moffett Field, Calif. CheMin, will identify and quantify all minerals in complex natural samples such as basalts, evaporites and soils, one of the principle objectives of Mars Science Laboratory.

— “Radiation Assessment Detector (RAD),” Donald Hassler, Southwest Research Institute, Boulder, Colo. RAD will characterize the broad spectrum of radiation at the surface of Mars, an essential precursor to human exploration of the planet. RAD will be funded by the Exploration Systems Mission Directorate at NASA Headquarters.

— “Mars Descent Imager,” Michael Malin, MSSS. The Mars Descent Imager will produce high-resolution color-video imagery of the MSL descent and landing phase, providing geological context information, as well as allowing for precise landing-site determination.

— “Sample Analysis at Mars with an integrated suite consisting of a gas chromatograph mass spectrometer, and a tunable laser spectrometer (SAM),” Paul Mahaffy, NASA’s Goddard Space Flight Center, Greenbelt, Md. SAM will perform mineral and atmospheric analyses, detect a wide range of organic compounds and perform stable isotope analyses of organics and noble gases.

Original Source: NASA News Release