Finding 40,000 Asteroids Before They Find Us

Plot of orbits of known potentially hazardous asteroids (size over 140m and passing within 7.6×106 km of Earth's orbit) as of early 2013 (Credit : NASA/JPL-Caltech)

Astronomers have just catalogued the 40,000th near Earth asteroid, a milestone that marks humanity's transformation from passive targets to active defenders of our planet. These space rocks, ranging from house sized boulders to some the size of mountains, follow orbits that bring them uncomfortably close to Earth. Each discovery adds another piece to our planetary defence puzzle, though current surveys have found only about 30 percent of the mid sized asteroids that could still cause regional devastation if they struck our world.

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Researchers Match Up 12 Meteorites with the Near-Earth Asteroids They Came From

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In our neighborhood of the Milky Way, we see a region surrounding the solar system that is far less dense than average. But that space, that cavity, is a very irregular, elongated shape. What little material is left inside of this cavity is insanely hot, as it has a temperature of around a million Kelvin. from Universe Today https://ift.tt/KvVDeiC via IFTTT

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