Posted on 03/14/2002 9:44:54 PM PST by petuniasevan
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: Looking for water on Mars, researchers using detectors on board the orbiting Mars Odyssey spacecraft have created this false-color global map of energetic neutrons from the otherwise Red Planet. What do neutrons have to do with water? As cosmic rays from interplanetary space penetrate the thin martian atmosphere and reach the surface they interact with elements in the upper layer of soil, scattering neutrons back into space. But if the martian soil contains hydrogen, it seriously absorbs energetic scattered neutrons. Tracking variations in absorption, neutron detectors can map changes in surface hydrogen content from orbit. Hydrogen content is taken as a surrogate measure of frozen water (H20), the most likely form of hydrogen close to the martian surface. Blue shades in the above map correspond to large concentrations of hydrogen, indicating in particular that the martian south polar region has a high amount of water ice near the surface.
Mars awaits our footprints.
Why DID we stop short? I was so disappointed, then and now. The Space Shuttle NEVER had the attraction for me that the Apollo program did. Why is it that we got to the moon repeatedly with 1960s technology -- computers that don't hold a candle to the one I'm using now, for instance -- and now we play parking orbit?
It's like a child who takes that big step, learns to swim in that big ocean, but becomes unsure and self-conscious.
Pretty soon he stays on the beach ("It's safer here.") Sure it is, but it's also giving up the stars for a bucket of sand.
By all rights we should already have bases on the moon, and of course an array of radio and visual telescopes on the far side.
We could - with a moderate effort - have sent a manned mission to Mars before the 20th century ended.
Sure there was once more water on Mars.
In fact, some evidence exists for ambient surface water early on, and catastrophic melting of permafrost later, from meteoric impact, perhaps.
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