06.21.2017 A.I. laser targeting
06.01.2017 Diagram of Lake Stratification on Mars
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
04.20.2017 Chemical Laptop Team
04.20.2017 Subcritical Water Extractor
04.20.2017 Chemical Laptop
04.20.2017 Atacama Landscape
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
10.17.2016 MAVEN Captures Rapid Cloud Formation
10.17.2016 Mars' Nightside Atmosphere
10.17.2016 Ultraviolet Image Near Mars' South Pole
10.17.2016 Ultraviolet Mars Reveals Cloud Formation
10.05.2016 Dust Haze Hiding the Martian Surface in 2001
10.04.2016 Test of Lander Vision System for Mars 2020
10.03.2016 A Sharpened Ultraviolet View of Mars
10.03.2016 Curiosity Self-Portrait at 'Murray Buttes'
Two Different Aqueous EnvironmentsThis 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. On the right are the rocks of the "Sheepbed" unit in Yellowknife Bay, in Gale Crater, as seen by Curiosity.
The rock on the left is formed from sulfate-rich sandstone. Scientists think the particles were in part formed and cemented in the presence of water. They also think the concretions (spherical bumps distributed across rock face) were formed in the presence of water. The Meridiani rocks record an ancient aqueous environment that likely was not habitable due the extremely high acidity of the water, the very limited chemical gradients that would have restricted energy available, and the extreme salinity that would have impeded microbial metabolism -- if microrganisms had ever been present.
In the Sheepbed image on the right, these very fine-grained sediments represent the record of an ancient habitable environment. The Sheepbed sediments were likely deposited under water. Scientists think the water cemented the sediments, and also formed the concretions. The rock was then fractured and filled with sulfate minerals when water flowed through subsurface fracture networks (white lines running through rock). Data from several instruments on Curiosity -- the Alpha Particle X-ray Spectrometer, the Chemistry and Camera instrument, the Chemistry and Mineralogy instrument, the Mars Hand Lens Imager, the Mast Camera, and the Sample Analysis at Mars instrument -- all support these interpretations. They indicate a habitable environment characterized by neutral pH, chemical gradients that would have created energy for microbes, and a distinctly low salinity, which would have helped metabolism if microorganisms had ever been present.
Both color images have been white-balanced using the same technique to show roughly what they would look like if they were on Earth.
The "true color" image from Opportunity's panoramic camera (Pancam) was acquired on Sol 250 (the 250th Martian day of Opportunity's operations, which was Oct. 6, 2004, on Earth).
The image from Sheepbed was from Curiosity's Mast Camera on Sol 192 (the 192d Martian day of Curiosity's operations, which was Feb. 18, 2013, on Earth).
Image Credit: NASA/JPL-Caltech/Cornell/MSSS