06.01.2017 Mars Reconnaissance Orbiter By the Numbers
05.15.2017 From 'Tribulation' to 'Perseverance' on Mars
03.29.2017 A Decade of Compiling the Sharpest Mars Map
03.09.2017 Back-to-Back Martian Dust Storms
02.08.2017 Mars Reconnaissance Orbiter Observes Changes
01.25.2017 'Wing' Dike of Hardened Lava in New Mexico
01.25.2017 Blade-Like Martian Walls Outline Polygons
01.06.2017 Earth and Its Moon, as Seen From Mars
11.15.2016 Schiaparelli Impact Site on Mars, Stereo
11.03.2016 Schiaparelli Impact Site on Mars, in Color
03.30.2016 Erisa Hines
03.30.2016 Buzz Aldrin
03.21.2016 For a Decade Orbiting Mars: One Recent View
03.09.2016 For a Decade Orbiting Mars: One Recent View
03.01.2016 MRO sees Frosty Spring Slopes
02.12.2016 Women in Science
02.10.2016 Wind at Work
11.16.2015 Change Observed in Martian Sand Dune
10.05.2015 'The Martian' Story's Ares 4 Landing Site
10.05.2015 The Ares 3 Landing Site (Figure A)
09.30.2015 Avalanche Ho!
06.29.2015 Mars Exploration Zone Layout Considerations
06.17.2015 Active High-Latitude Dune Gullies
06.03.2015 Crisp Crater in Sirenum Fossae
05.20.2015 Sedimentary Rock Layers on a Crater Floor
05.20.2015 Honey, I Shrunk the Mesas
05.11.2015 Icy Wonderland
05.04.2015 Diverse Orbits Around Mars
03.27.2015 South Pole Spiders
03.27.2015 A Smile a Day....
03.25.2015 Pitted Landforms in Southern Hellas Planitia
03.12.2015 Curiosity Heading Away from 'Pahrump Hills'
02.18.2015 Lava Flow Near the Base of Olympus Mons
02.09.2015 Yardangs in Arsinoes Chaos, Mars
02.04.2015 Curiosity Rover at 'Pahrump Hills'
01.22.2015 Frost on Crater Slope
First Observation of Columnar Jointing on MarsThis image from the High Resolution Imaging Science Experiment (HiRISE) on NASA's Mars Reconnaissance Orbiter shows an exposure of layered rock that exhibits a type of fracturing -- called columnar jointing -- that results when cooling lava contracts.
The observation is cited in a report, "Discovery of Columnar Jointing on Mars," in the February 2009 issue of the journal Geology. The authors propose that flooding by water was likely what caused a quick cooling of lava to result in this jointing.
The image, taken Oct. 31, 2007, shows a portion of an unnamed crater 16 kilometers (10 miles) in diameter and centered at 21.52 degrees north latitude, 184.35 degrees north longitude. Shown here is a section about one kilometer (0.6 mile) wide from the image catalogued by the HiRISE team as PSP_005917_2020. The column-forming fractures resemble textures common on Earth in locations such as the Colombia River Basalt Group and in the Colorado Plateau.
Image Credit: NASA/JPL-Caltech/University of Arizona