A colorful marriage of old and young
Thu Sep 20, 2007 at 09:41 UTC
On the southwest edge of the immense volcanic region of Tharsis, lava from its giant volcanoes flowed down to meet the old cratered landscape of Terra Sirenum. Scientists can't say how many years separate the flows from the terrain they engulfed, but the relationship between the two tells of a complex tale.
This false-color mosaic image combines separate frames taken by the Thermal Emission Imaging System (THEMIS) on NASA's Mars Odyssey orbiter. THEMIS photographs Mars in 10 infrared "colors" and five visible ones.
The infrared imaging gives scientists clues about the nature of the surface. THEMIS photographs patches of ground twice per Martian day - once in late afternoon and then again just before night ends - two times when contrasts in surface temperature are strongest.
Under full sunlight, dust, sand, and loose sediments grow warm, even hot, as anybody knows who has walked barefoot across a sunny beach. (Dark materials also do the same.) In the depths of night on Mars, however, fine particles quickly become cold as temperatures plunge after sundown. But rocky areas and ones with expanses of compacted sediments hold onto heat better and glow warmly in THEMIS' infrared vision.
Image Credit: NASA/JPL-Caltech/ASU
High resolution image (1.9 MB)
Primordial and prehistoric come together in a lasting bond of something old, something new, something orange, and something blue. In this false-color image, blue signals cooler sand or dust around an ancient crater, which dates back to a violent time of cataclysmic collisions about 4 billion years ago, shortly after Mars formed. Later, sheets of lava streamed across the surface and lapped against the crater walls. These younger lava rocks "glow" orange and yellow since they retain more heat at night than the sand and dust.
| Source: Arizona State University | |
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