Tectonic fractures within Candor Chasma retain
their ridge-like shapes as the surrounding bedrock
erodes away. The fractures have a light tone
presumably because liquid water altered their
chemical composition. NASA/JPL/ University of Arizona
The Mars Reconnaissance Orbiter (MRO) continues to set records. The sophisticated spacecraft, still only 3 months into its primary science mission, has already returned to Earth more data than any previous spacecraft sent to Mars. The data — enough to fill nearly 1,000 CD-ROMs — breaks the record set by Mars Global Surveyor during 9 years of martian observations, from 1997 to 2006.
The first paper reporting MRO science results came out in the February 16 issue of the journal Science. In it, Chris Okubo and Alfred McEwen of the University of Arizona report their discovery of cracks through which liquid likely flowed beneath the martian surface. Using images from the High Resolution Imaging Science Experiment (HiRISE), Okubo first noticed the intriguing fractures in an image of exposed layers in Candor Chasma, a small part of the vast Valles Marineris canyon system.
The fractures stood out because they appeared much lighter in color than their surroundings. Okubo and McEwen think the cracks were bleached when minerals, dissolved in water, came out of solution, becoming part of the rocky material lining the fractures. This mineralization took place deep underground. The bleached fractures became visible only after the overlying layers eroded over millions of years.
Although MRO continues to return unprecedented amounts of data, all is not perfect with the spacecraft. A few of the HiRISE detectors are experiencing increased levels of noise, such as bad pixels. So far, the effect on image quality is low, but mission managers are concerned the problem could worsen. And the field of view of the Mars Climate Sounder, which maps the temperature, ice clouds, and dust distribution in the atmosphere, intermittently moves slightly out of position.
Still, the rate at which data is coming back should increase over the coming months, as the distance between Earth and Mars shrinks. You can bet we'll have plenty more to talk about as the year progresses.