July 14, 2004
A birthday is what happens when cosmic time briefly puts down the scale of eons and pays attention to a single human year.
Polar Polygons on Mars
Birthday · July 14, 2004
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APOD published July 14, 2004. Credit: Malin Space Science Systems, MOC, MGS, JPL, NASA. A publication-date match, not a photo taken on your date. Independent of NASA.
What's the best way to the city center? What looks like a street map of some city on Earth is actually a series of naturally-formed fragmented polar polygons on Mars. The existence of polar polygons on Mars is particularly interesting as they may indicate regions where water ice lies within a few meters of the surface. Similar looking polygons are commonly found in the arctic and Antarctic of Earth, where they typically form from a repetitive cycle of freezing and thawing. The above image spans a distance of about 3 kilometers and was taken recently by the orbiting Mars Global Surveyor.
Image credit: Malin Space Science Systems, MOC, MGS, JPL, NASA