Water in Martin desert

Searching for water near Tagus Valles

Craters once brim-full with sediments and water have long since drained dry, but traces of their former lives as muddy lakes cling on in the martian desert.

The 34 km-wide crater in the top left of the main images perhaps draws most attention with its chaotic interior. Here, broad flat-topped blocks called mesas can be found alongside smaller parallel wind-blown features known as yardangs.The images were taken on 15 January by ESA’s Mars Express, and feature a region just a few degrees south of the equator within the ancient southern highlands of Mars. The unnamed region lies immediately to the north of an ancient riverbed known as Tagus Valles and east of Tinto Valles and Palos crater that were presented in an earlier release.

Both mesas and yardangs were carved from sediments that originally filled the crater, deposited there during a flood event that covered the entire scene. Over time, the weakest sediments were eroded away, leaving the haphazard pattern of stronger blocks behind.

Colour-coded topography of Tagus Valles region

Further evidence of this crater’s watery past can be seen in the top right of the crater in the shape of a small, winding river channel.

Clues also hang onto the ghostly outline of an ancient crater some 20 km to the east (below in the main images). While the crater has all but been erased from the geological record, a long meandering channel clearly remains, and flows towards the crater in the centre of the scene.

This central complex of craters is seen close up in the perspective view below, showing in more detail another channel-like feature, along with a highly deformed crater. Perhaps the rim of this eroded crater was breached as sediments flooded the larger crater.

Deformation in a flooded crater

The crater is also seen from a different angle and in the background of the second perspective view below. In the foreground is one of the deepest craters in the scene, as indicated by the topography map.

Numerous landslides have occurred within this crater, perhaps facilitated by the presence of water weakening the crater walls. Grooves etched into the crater’s inner walls mark the paths of tumbling rocks, while larger piles of material have slumped en-masse to litter the crater floor.

Landslides inside a crater

group of interconnected craters with flat floors smoothed over by sediments lie in the lower right part of the main image. One small crater with a prominent debris deposit – an ejecta blanket – lies within the crater.

Ejecta blankets are composed of material excavated from inside the crater during its formation. This particular crater exhibits a ‘rampart’ ejecta blanket – one with petal-like lobes around its edges. Liquid water bound up in the ejected material allowed it to flow along the surface, giving it a fluid appearance.

Tagus Valles region in 3D

But it’s not just water that has played a role in this region; volcanic eruptions have also had their say. A dark layer of fine-grained ash covers the top left corner of the main image that may have been deposited from the Elysium volcanic province to the northeast. Over time, the ash was redistributed by wind, and buried deposits exposed in localised areas by erosion.

This region is one of many that exposes evidence of the Red Planet’s active past, and shows that the marks of water are engraved in even the most unlikely ancient crater-strewn fields.

Source : ESA 

By :Science and Universe

Curiosity Makes Its Longest One-Day Drive on Mars

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<<Image : View From Curiosity's Arm-Mounted Camera After a Long Drive

The Mars Hand Lens Imager (MAHLI) camera on NASA's Curiosity rover is carried at an angle when the rover's arm is stowed for driving. Still, the camera is able to record views of the terrain Curiosity is crossing in Gale Crater, and rotating the image 150 degrees provides this right-side-up scene. The scene is toward the south, including a portion of Mount Sharp and a band of dark dunes in front of the mountain. It was taken on the 140th Martian day, or sol, of Curiosity's work on Mars, shortly after Curiosity finished a 329.1-foot (100.3-meter) drive on that sol. The drive was twice as long as any previous sol's drive by Curiosity.

When the robotic arm, turret, and MAHLI are stowed, the MAHLI is looking out from the front left side of the rover. This is much like the view from the driver's side of cars sold in the USA.

The main purpose of Curiosity's MAHLI camera is to acquire close-up, high-resolution views of rocks and soil at the rover's Gale Crater field site. The camera is capable of focusing on any target at distances of about 0.8 inch (2.1 centimeters) to infinity. This means it can, as shown here, also obtain pictures of the Martian landscape.

Malin Space Science Systems, San Diego, developed, built and operates MAHLI. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Mars Science Laboratory Project and the mission's Curiosity rover for NASA's Science Mission Directorate in Washington. The rover was designed and assembled at JPL, a division of the California Institute of Technology in Pasadena.

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NASA's Mars rover Curiosity drove twice as far on July 21 as on any other day of the mission so far: 109.7 yards (100.3 meters). 

The length of the drive took advantage of starting the 340th Martian day, or sol, of the mission from a location with an unusually good view for rover engineers to plan a safe path. In weeks to come, the rover team plans to begin using "autonav" capability for the rover to autonomously navigate a path for itself, which could make such long drives more frequent. 

Curiosity is about three weeks into a multi-month trek, from the "Glenelg" area where it worked for the first half of 2013, to an entry point for the mission's major destination: the lower layers of Mount Sharp. The mission's longest one-day drive prior to July 21 was about 54 yards (49 meters), on Sol 50 (Sept. 26, 2012). After completing the longer drive, Curiosity drove 68.2 yards (62.4 meters) on July 23 (Sol 342), bringing the mission's total driving distance so far to 0.81 mile (1.23 kilometers). 

The Sol 340 drive included three segments, with turns at the end of the first and second segments. Rover planners used information from stereo imaging by the Navigation Camera (Navcam) on Curiosity's mast, plus images from the telephoto-lens Mast Camera (Mastcam). The drive also used the rover's capability to use imagery taken during the drive to calculate the driving distance, a way to verify that wheels have not been slipping too much while turning. 

"What enabled us to drive so far on Sol 340 was starting at a high point and also having Mastcam images giving us the size of rocks so we could be sure they were not hazards," said rover planner Paolo Bellutta of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We could see for quite a distance, but there was an area straight ahead that was not clearly visible, so we had to find a path around that area." 

The rover was facing southwest when the sol began. It turned slightly more to the west before driving and used visual odometry to be sure it drove the intended distance (about 55 yards or 50 meters) before turning back farther southward. The second leg, next turn, and third leg completed the drive without visual odometry, though the rover was using another new capability: to turn on visual odometry autonomously if tilt or other factors exceed predetermined limits. 

New software on Curiosity gives it the capability to use visual odometry through a range of temperatures. This was needed because testing this spring indicated the Navcam pair linked to the rover's B-side computer is more sensitive to temperature than anticipated. Without the compensating software, the onboard analysis of stereo images could indicate different distances to the same point, depending on the temperature at which the images are taken. The rover was switched from its A-side computer to the redundant B-side computer on Feb. 28 due to a flash-memory problem -- subsequently resolved -- on the A-side. The Navcam pair linked to the A-side computer shows less variability with temperature than the pair now in use. 

"For now, we're using visual odometry mostly for slip-checking," said JPL's Jennifer Trosper, deputy project manager for Curiosity. "We are validating the capability to begin using autonav at different temperatures." 

The autonomous navigation capability will enable rover planners to command drives that go beyond the route that they can confirm as safe from previous-sol images. They can tell the rover to use the autonomous capability to choose a safe path for itself beyond that distance. 

Curiosity landed at the "Bradbury Landing" location within Gale Crater on Aug. 6, 2012, EDT and Universal Time (Aug. 5, PDT). From there, the rover drove eastward to the Glenelg area, where it accomplished the mission's major science objective of finding evidence for an ancient wet environment that had conditions favorable for microbial life. The rover's route is now southwestward. At Mount Sharp, in the middle of Gale Crater, scientists anticipate finding evidence about how the ancient Martian environment changed and evolved. 

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover. 

More information about Curiosity is online at http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl andhttp://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook athttp://www.facebook.com/marscuriosity and on Twitter at http://www.twitter.com/marscuriosity .

Credit : NASA/JPL
By Science and Universe

Odyssey has spotted a dune "dinosaur" on Mars.

Do you see what I see? These polar dunes look like T-rex, complete with his little arm.

Context

The Odyssey orbiter has spotted a dune "dinosaur" on Mars. Clever girl. 

 Latitude: -68.2367

Longitude: 191.998

Orbit Number: 40690

Captured: 2011-02-15 16:46

Posted to Web: Mon, 2013-07-15

Instrument: IR

Image Width: 320 pixels (30 km)

Image Height: 1040 pixels (105 km)

Vertical Resolution: 0.101323 km/pixel

Horizontal Resolution: 0.095631 km/pixel

NASA Rover Finds Conditions Once Suited for Ancient Life on Mars

Two Different Aqueous Environments

This set of images compares rocks seen by NASA's Opportunity rover and Curiosity rover at two different parts of Mars. On the left is " Wopmay" rock, in Endurance Crater, Meridiani Planum, as studied by the Opportunity rover. 

An analysis of a rock sample collected by NASA's Curiosity rover shows ancient Mars could have supported living microbes. 

Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon -- some of the key chemical ingredients for life -- in the powder Curiosity drilled out of a sedimentary rock near an ancient stream bed in Gale Crater on the Red Planet last month. 

"A fundamental question for this mission is whether Mars could have supported a habitable environment," said Michael Meyer, lead scientist for NASA's Mars Exploration Program at the agency's headquarters in Washington. "From what we know now, the answer is yes." 

Clues to this habitable environment come from data returned by the rover's Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments. The data indicate the Yellowknife Bay area the rover is exploring was the end of an ancient river system or an intermittently wet lake bed that could have provided chemical energy and other favorable conditions for microbes. The rock is made up of a fine-grained mudstone containing clay minerals, sulfate minerals and other chemicals. This ancient wet environment, unlike some others on Mars, was not harshly oxidizing, acidic or extremely salty. 

The patch of bedrock where Curiosity drilled for its first sample lies in an ancient network of stream channels descending from the rim of Gale Crater. The bedrock also is fine-grained mudstone and shows evidence of multiple periods of wet conditions, including nodules and veins. 

Curiosity's drill collected the sample at a site just a few hundred yards away from where the rover earlier found an ancient streambed in September 2012. 

"Clay minerals make up at least 20 percent of the composition of this sample," said David Blake, principal investigator for the CheMin instrument at NASA's Ames Research Center in Moffett Field, Calif. 

These clay minerals are a product of the reaction of relatively fresh water with igneous minerals, such as olivine, also present in the sediment. The reaction could have taken place within the sedimentary deposit, during transport of the sediment, or in the source region of the sediment. The presence of calcium sulfate along with the clay suggests the soil is neutral or mildly alkaline. 

Scientists were surprised to find a mixture of oxidized, less-oxidized, and even non-oxidized chemicals, providing an energy gradient of the sort many microbes on Earth exploit to live. This partial oxidation was first hinted at when the drill cuttings were revealed to be gray rather than red. 

"The range of chemical ingredients we have identified in the sample is impressive, and it suggests pairings such as sulfates and sulfides that indicate a possible chemical energy source for micro-organisms," said Paul Mahaffy, principal investigator of the SAM suite of instruments at NASA's Goddard Space Flight Center in Greenbelt, Md. 

An additional drilled sample will be used to help confirm these results for several of the trace gases analyzed by the SAM instrument. 

"We have characterized a very ancient, but strangely new 'gray Mars' where conditions once were favorable for life," said John Grotzinger, Mars Science Laboratory project scientist at the California Institute of Technology in Pasadena, Calif. "Curiosity is on a mission of discovery and exploration, and as a team we feel there are many more exciting discoveries ahead of us in the months and years to come." 

Scientists plan to work with Curiosity in the "Yellowknife Bay" area for many more weeks before beginning a long drive to Gale Crater's central mound, Mount Sharp. Investigating the stack of layers exposed on Mount Sharp, where clay minerals and sulfate minerals have been identified from orbit, may add information about the duration and diversity of habitable conditions. 

NASA's Mars Science Laboratory Project has been using Curiosity to investigate whether an area within Mars' Gale Crater ever has offered an environment favorable for microbial life. Curiosity, carrying 10 science instruments, landed seven months ago to begin its two-year prime mission. NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the project for NASA's Science Mission Directorate in Washington. 

Source : JPL.NASA.GOV