A team of international researchers said on Tuesday they have found what could be the first proof of life beyond our planet — clumps of extraterrestrial bacteria in the Earth’s upper atmosphere. Although the bugs from space are similar to bacteria on Earth, the scientists said the living cells found in samples of air from the edge of the planet’s atmosphere are too far away to have come from Earth. As much as a third of a ton of the biological material is raining down over the entire planet daily, by their estimation.