08.09.2017 Clouds Sailing Overhead on Mars, Enhanced
08.09.2017 Clouds Sailing Overhead on Mars, Unenhanced
07.20.2017 Panorama Above 'Perseverance Valley' on Mars
07.20.2017 Compass and Scale Image for Phobos and Mars
07.20.2017 Phobos in Orbit around Mars
07.11.2017 'Nathan Bridges Dune' on a Martian Mountain
07.11.2017 'Ireson Hill' on Mount Sharp, Mars
07.11.2017 Mars 2020 CacheCam Sample Tube
06.29.2017 Traction control testing
06.21.2017 A.I. laser targeting
06.01.2017 Diagram of Lake Stratification on Mars
06.01.2017 Mars Reconnaissance Orbiter By the Numbers
05.23.2017 Testing Mars 2020's Engineering Cameras
05.22.2017 NASA's Mars 2020 Rover Artist's Concept #1
05.15.2017 Putting Martian 'Tribulation' Behind
05.15.2017 From 'Tribulation' to 'Perseverance' on Mars
03.30.2017 Measuring Mars' Atmosphere Loss
03.29.2017 Lifetime Achievement Award to Theisinger
03.29.2017 A Decade of Compiling the Sharpest Mars Map
03.21.2017 Break in Raised Tread on Curiosity Wheel
03.17.2017 COBALT/JPL team
03.09.2017 Back-to-Back Martian Dust Storms
02.27.2017 Swirling Dust in Gale Crater, Mars, Sol 1613
02.27.2017 Dust Devil Passes Near Martian Sand Dune
02.27.2017 Sand Moving Under Curiosity, One Day to Next
02.08.2017 Mars Reconnaissance Orbiter Observes Changes
01.26.2017 Mono Lake
01.25.2017 'Wing' Dike of Hardened Lava in New Mexico
01.25.2017 Blade-Like Martian Walls Outline Polygons
01.23.2017 Spirit And Opportunity By The Numbers
01.10.2017 Mars 2020 Rover - Artist's Concept
01.06.2017 Earth and Its Moon, as Seen From Mars
12.13.2016 Now and Long Ago at Gale Crater, Mars
12.13.2016 Where's Boron? Mars Rover Detects It
11.15.2016 Schiaparelli Impact Site on Mars, Stereo
11.03.2016 Schiaparelli Impact Site on Mars, in Color
Possible Mud Cracks Preserved in Martian RockThe network of cracks in this Martian rock slab called "Old Soaker" may have formed from the drying of a mud layer more than 3 billion years ago. The view spans about 4 feet (1.2 meters) left-to-right and combines three images taken by the Mars Hand Lens Imager (MAHLI) camera on the arm of NASA's Curiosity Mars rover.
Mud cracks would be evidence of a time when dry intervals interrupted wetter periods that supported lakes in the area. Curiosity has found evidence of ancient lakes in older, lower-lying rock layers and also in younger mudstone that is above Old Soaker.
MAHLI was positioned about 3 feet (90 centimeters) above the surface when it took the component images on Dec. 31, 2016, during the 1,566th Martian day, or sol, of Curiosity's work on Mars. This observation was planned as part of assessing a hypothesis that the target preserves evidence of drying mud. The location is within an exposure of Murray formation mudstone on lower Mount Sharp inside Gale Crater.
The slab bears a network of four- and five-sided polygons about half an inch to 1 inch (1 to 2 centimeters) across, which matches the pattern commonly formed when a thin layer of mud dries. Some edges of the polygons are ridges of material the same color as the surrounding rock. This could result from a three-step process after cracks form due to drying: Wind-blown sediments accumulate in the open cracks. Later, these sediments and the dried mud become rock under the pressure of multiple younger layers that accumulate on top of them. Most recently, after the overlying layers were eroded away by wind, the vein-filling material resists erosion better than the once-muddy material, so the pattern that began as cracks appears as ridges.
Note that some of the cracks contain material much brighter than the surrounding rock. These are mineral veins. Curiosity has found such bright veins of calcium sulfate in many rock layers the rover has investigated. These veins form from circulation of mineral-laden groundwater through underground cracks. Rover-team scientists suggest that a likely scenario for the history of Old Soaker is more than one generation of fracturing: mud cracks first, with sediment accumulating in them, then a later episode of underground fracturing and vein forming.
The target rock's name comes from the name of an island off the coast of Maine. The names informally assigned by the rover team to features in the area of lower Mount Sharp that includes this slab are from a list of islands, hills and other sites in or near Maine's Bar Harbor.
Malin Space Science Systems, San Diego, built and operates MAHLI. NASA's Jet Propulsion Laboratory, a division of the Caltech in Pasadena, California, manages the Mars Science Laboratory Project for the NASA Science Mission Directorate, Washington, and built the project's Curiosity rover. More information about Curiosity is online at http://www.nasa.gov/msl and http://mars.nasa.gov/msl/.
Image Credit: NASA/JPL-Caltech/MSSS