Amateur Telescopes Can Track A Massive Asteroid Hurtling Past Earth This Weekend

Backyard astronomers will be able to use their telescopes to focus in on a massive cosmic visitor when it "skims" past Earth this weekend. On June 27 especially, a large asteroid known as (152637) 1997 NC1 will make a close but entirely harmless flyby in plain view, as long as you don't mind staying up to catch it and have the right equipment.

Discovered nearly three decades ago by the Near-Earth Asteroid Tracking system in Hawaii, this asteroid is a titan compared to typical near-Earth objects. It's estimated to be between 750 and 1,650 meters (0.4-1.0 mile) across, making it roughly 60 times wider than the Chelyabinsk meteor that shattered windows across Russia in 2013. If an object of this magnitude were to collide with Earth, it would level cities, strip landscapes for hundreds of miles, and loft enough dust into the stratosphere to trigger a mini ice age. Fortunately, global space agencies have thoroughly ruled out any threat of impact.

For the rest of us, the asteroid's size and proximity mean it will shine at a relatively bright magnitude of 10. Anyone with a 6-inch telescope or high-powered binoculars will be able to watch the asteroid sail across in real-time. Because of its velocity, observers who lock their instruments onto the correct coordinates will notice the star-like object visibly shifting against the background constellations on a timescale of roughly five to seven minutes.

Finding it requires a dark sky and proper targeting, of course. The optimal viewing window spans from June 26-28. On the peak night of June 27, observers in the Northern Hemisphere should point their telescopes toward the constellation Sagittarius, focusing just above the Teapot asterism around 10:00 p.m. local time. The asteroid will transition across global skies as it travels, becoming visible nearly everywhere at the exact moment of its closest approach before slipping into the view of the Southern Hemisphere as it departs.