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Zoom in on Mars:
New Highly Detailed Images
by Robert Roy Britt
15 October 2002
A new image from the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) reveal the ridges to be part of a larger circular structure that's about 53 miles (86 kilometers) across. "It is possible that this pattern reflects an origin related to an ancient, eroded meteor impact crater that was filled-in, buried, then partially exhumed," according to scientists at Malin Space Science Systems, which operates the camera for NASA. "In this case, the ridges might be the remains of filled-in fractures in the bedrock into which the crater formed, or filled-in cracks within the material that filled the crater. Or both explanations could be wrong."
Ghosts of Impacts Past:
Ancient Hidden Craters on Mars Revealed
by Robert Roy Britt
05 November 2002
Images obtained by SPACE.com reveal hints of circular outlines and subtle depressions that appear to be craters created during tremendous asteroid or comet impacts that pummeled the Red Planet’s original crust 4 billion years ago or more. The features have since been mostly buried or eroded away... If the entombed craters exist as suspected, then the current visible surface of Mars does not represent the original crust, as some scientists have thought... Mars, Earth and the other planets are thought to have formed about 4.5 or 4.6 billion years ago. A period of heavy bombardment likely ensued, as countless rocks were cleared from the fledgling solar system. A record of the bombardment remains on the Moon, where little erosion or geologic activity takes place... "Erin's results show that the assumption many people have made that the oldest visible surface units go back to 4.6 billion years ago is wrong," the father told SPACE.com. "That means the absolute time scales people have tried to use are probably wrong. It also means there is a recoverable history on Mars that we cannot easily see, except in terms of the crater record. The surface we see is not the original crust of Mars, but something younger."