Impact excavates a uniquely useful crater, 9 km across. This is Omaha Crater, named after the U.S. Army’s most hard-won D-Day beachhead. Omaha Crater is dotted at creation with a pattern of worksite depressions. Bedrock holds one quintillion (1018
) Joules of impact heat, centered on the new, lowest point on Mars. Here 1.3 kPa of atmospheric pressure, the depressions, and crater heat make possible a lake and other reservoirs for settlement use. Water surface temperature is set via circulation and heat exchange below 11 °
C to prevent boil-off.
In time, settlement industries will vent excess oxygen into the crater, forming a protective local ozone layer. Ozone, heat and the pressure of air and water set the stage for a photosynthetic archipelago on the open crater floor – a true terraformation site, with appearance similar to the masthead site, Alaska's Aniakchak caldera.
The terraformation resources persist beyond our time. Omaha Crater bedrock will remain warm to the touch for thousands of years.