Source: NBC News
When Mars was being bombarded with giant asteroids and comets over four billion years ago, the giant space rocks were enhancing the climate.
A new study from the University of Colorado Boulder says that the comets and asteroids actually enhanced the climate enough to make Mars’ environment more conductive to life for a time.
The bombardment occurred during a period known as the Late Heavy Bombardment, which was about 3.9 billion years ago when the solar system was developing.
CU-Boulder Professor Stephen Mojzsis said if early Mars was as barren and cold as it is today, massive asteroid and comet impacts would have produced enough heat to melt subsurface ice. The impacts would have produced areas of regional hydrothermal systems on Mars similar to those in Yellowstone National Park, which today harbor chemically powered microbes, some of which can survive boiling in hot springs or inhabiting water acidic enough to dissolve nails.
In addition to the hydrothermal regions on Mars’ fractured, melted crust, a massive impact could have temporarily increased atmospheric pressure. This would cause the planet to heat up enough to “re-start” a dormant water cycle, Mojzsis says.
The study, which used the Janus supercomputer cluster at CU-Boulder, showed the heating of Mars caused the individual collisions would have lasted a few million years before returning to a cold state.
In the study, Mojzsis and Oleg Abramov, a researcher at the U.S. Geological Survey in Flagstaff, Ariz. and a former CU-Boulder research scientist under Mojzsis, looked at temperatures beneath millions of individual craters in their computer simulations to assess heating and cooling, as well as the effects of impacts on Mars from different angles and velocities. A single model comprising the whole surface of Mars took up to two weeks to run on the supercomputer cluster, said Mojzsis.
The scientists study Mars because it provides information on Earth’s place in the solar system.