Minute droplets of oil from 2.4 billion years ago are providing evidence that life on Earth survived a period when the planet was covered with more than a half-mile of snow; an era affectionately deemed "Snowball Earth." The oil, retrieved from ancient rock crystals, contains molecular fossils that scientists can identify as having come from specific life forms. A paper published in the June edition of Geology concludes that eukaryotes and cyanobacteria were alive before "Snowball Earth" and survived the hostile period.
The same meteor that created a 300 mile-wide crater in Antarctica may have also caused a massive extinction 250 million years ago, Ohio State University geologist Ralph von Frese announced on Wednesday. Satellite data shows that the crater, which lies more than a mile beneath a sheet of ice, dates back to the same period as the Permian-Triassic extinction, when nearly all of Earth's animal life died out. Scientists had believed that a series of volcanic eruptions caused the extinction that cleared the stage for the dinosaurs to inherit the Earth.
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