Close call: Mountain-size asteroid to zoom past Earth on Monday

A mountain-size asteroid will zoom past Earth on Monday, marking the closest pass by such a large space rock until 2027. Asteroid 2004 BL86, which is 550 metres wide, will come within 1.2 million kilometres of our planet—about three times the distance between Earth and the moon. While this flyby poses no threat to Earth, it does present a rare opportunity to get a good look at a near-Earth asteroid, NASA officials say.

For objects that get this close, that are this large, the radar observations are really analogous to a spacecraft flyby in terms of the caliber of the data that we can get.

Lance Benner of NASA’s Jet Propulsion Laboratory

Scientists are eager to study 2004 BL86 to pinpoint its orbit, observe its surface and even look for moons. The plan is to track the fast-moving asteroid using the 70 m dish-shaped Goldstone antenna at NASA’s Deep Space Network in California, as well as the 305 m Arecibo Observatory in Puerto Rico. These radio dishes will beam microwave signals at the asteroid, which will then bounce off the target and return to Earth.

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