Meteorite bombardment may have made Earth more habitable, says study

Meteorite bombardment may have made Earth more habitable, says study. Ancient meteorite bombardments release gases that could make Earth and Mars more habitable for life %0A " - For Immediate Release - Monday 1 June 2009 Large bombardments of meteorites approximately four billion years ago could have helped to make the early Earth and Mars more habitable for life by modifying their atmospheres, suggests the results of a paper published today in the journal Geochimica et Cosmochima Acta. When a meteorite enters a planet's atmosphere, extreme heat causes some of the minerals and organic matter on its outer crust to be released as water and carbon dioxide before it breaks up and hits the ground. Researchers suggest the delivery of this water could have made Earth's and Mars' atmospheres wetter. The release of the greenhouse gas carbon dioxide could have trapped more energy from sunlight to make Earth and Mars warm enough to sustain liquid oceans. In the new study, researchers from Imperial College London analysed the remaining mineral and organic content of fifteen fragments of ancient meteorites that had crashed around the world to see how much water vapour and carbon dioxide they would release when subjected to very high temperatures like those that they would experience upon entering the Earth's atmosphere. The researchers used a new technique called pyrolysis-FTIR, which uses electricity to rapidly heat the fragments at a rate of 20,000 degrees Celsius per second, and they then measured the gases released.