NASA to launch new mission to Mars to probe below the crust (+video)
NASA'S first mission deep below the surface of Mars aims to understand how the Red Planet formed and how that geological history compares with that of another rocky planet – Earth.
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The mission beat two other finalists for this round of Discovery missions. A proposed Comet Hopper mission would put a lander on comet 46P/Wirtanen, where it would study the comet's composition and track changes in its nucleus as it moves through its orbit. The lander would have included thrusters that would allow it to "hop" from one location on the nucleus to another. Another mission would have essentially sent a high-tech buoy to a vast methane sea on Saturn's moon Titan to study its composition and its interaction with the atmosphere.Skip to next paragraph
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All contained compelling science, Grunsefeld said. But InSight was the only one that project reviewers inside and outside NASA felt stood the best chance of coming in at or under the Discovery program's $425 million cost cap, excluding launch costs, and within the tight schedule the program demands.
With budgets facing an ever tighter squeeze from Congress and the White House, the agency could ill afford delays that would stretch out other Discovery missions and boost their costs, Grunsfeld said.
One reason InSight looked like a safer financial bet is that it is based on lander and entry-stage designs developed for the Mars Phoenix Lander, and the failed Mars Polar Lander before it. Phoenix landed successfully and spent five months in 2008 studying a site in Mars' Arctic region.
InSight, by contrast, is slated to land near Mars' equator and operate for at least two years.
At first blush, Mars might look like a tectonic has-been. But over the past decade, orbiters detected landslides, uncovered tenuous hints of methane in the atmosphere, which can have a geothermal origin, and some scientists say they have seen surface features that suggest faults.
Indeed, in early August, An Yin, a geophysicist at the University of California at Los Angeles, published an analysis of images of Mars' Valles Marineris, the solar system's larges canyon, and pointed to evidence that two large crustal plates are sliding past each other. The fault defining the boundary runs along the length of the nearly 2,500 mile-long scar in the Martian crust.
Dr. Yin saw in the images what he interprets as features that are offset on either side of the fault by about 93 miles. Compared with Earth, Mars is smaller and its interior cooler, so it would have fewer plates. And those it has would move much more slowly than Earth's plates do.
The fault may become active every million years or so, he estimates. The results were published recently in the journal Lithosphere.