An asteroid that recently passed by Earth is about twice as large as originally estimated, and it would have had serious global consequences if it had impacted Earth. Asteroid 2012 LZ1 was only discovered on June 10, 2012 by Rob McNaught at the Siding Spring Observatory in Australia. This Near Earth Object was thought to be fairly large, 502 meters (1,650 feet) wide, and quite bright. But astronomers using the planetary radar system at Arecibo Observatory were able to better determine the asteroid’s size, rotation rate and shape and found it to be about 1 kilometer (0.6 miles) wide and actually quite dark.
Scientists consider a kilometer-wide asteroid is at the size threshold that could set off an extinction-level event if it were to hit Earth.
“This object turned out to be quite a bit bigger than we expected, said Dr. Ellen Howell from Arecibo, “which shows how important radar observations can be, because we’re still learning a lot about the population of asteroids.”
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