Curiosity is sending evidence of a new discovery home to NASA. Images from the rover’s camera show what could be an ancient stream bed.
Outcroppings of rock, named “Hottah” by NASA scientists after Hottah Lake in Canada’s Northwest Territories, are showing striking similarities with dried-up streams on Earth.
Hottah seems to be made of sedimentary conglomerate, which is a fancy way of saying big and little rocks glued together by time and pressure – possibly from water. Many of these rocks and others nearby are rounded, suggesting they were smoothed by a quick-moving stream. Curiosity also found a trail of sediment leading from high ground down to the bottom of the crater where it landed, called an alluvial fan – more evidence of an old stream that carried the sediment along as it flowed, and left it behind when it dried out.
Take a look at Curiosity’s latest snaps, along with some analogous shots of Earthly stream beds.
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- Compare the dry stream bed Curiosity found on Mars on the left with the dry Earthly river on the right.
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- An example of “sedimentary conglomerate” on Mars, a mish-mash of different sized rocks commonly found in dry riverbeds.
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- Colors in this image show the ability of the ground to retain heat, the areas in red being able to stay the warmest. Sedimentary conglomerate is tightly packed and would be able to stay warmer than the surrounding surface.
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- Sediment spreading out downslope to lower ground (cooler colors) indicates a stream was present, leaving the sediment as it flowed, and, eventually, dried out.
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- Outcroppings of rock with water-smoothed pebbles, named “Hottah” after Hottah Lake in Canada.
Scientific Chicago 