At least twice in Earth’s history, almost the entire planet was locked in a layer of snow and ice. These dramatic “Snowball Earth” events occurred in rapid succession, somewhere around 700 million years ago, and evidence suggests that consecutive global glaciations set the stage for the subsequent explosion of complex, …
Read More »At first astronomers see the crown of a black hole disappear and then reappear
It seems that the universe has a strange sense of humor. While a crown-encrusted virus has rushed around the world, a completely different corona about 100 million light-years from Earth has mysteriously disappeared. For the first time, astronomers at MIT and elsewhere have seen how the corona of a supermassive …
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