'Hazardous' Asteroid Will Barely Miss Earth in a Few Hours—Why Did It Take NASA So Long to Find It?

Science News
Tuesday, 02 January 2018 - 10:22AM

It seems like the Earth's new global asteroid defense system is doing its job: we've spotted an approaching asteroid the size of a truck that's heading right for our planet. But with NASA admitting it's potentially "hazardous" to Earth, why did it take us so long to find it? 

This large asteroid, which is between six and 21 meters in length, was only discovered on December 28, when it was spotted by the Mount Lemmon Observatory in Arizona. Named 2017 YD7, this is going to be one of the first big rocks to head towards our planet this year.

The bad news is that despite our planetary defense system now monitoring the asteroid, there's not much we can do about it. We haven't yet built a proposed Death Star-esque method for dealing with these rocky intruders, and there's no way to stop the asteroid from brushing up against the Earth at its anticipated arrival time of 0:40 UTC on January 3 (7:40 pm EST).

The good news is that the asteroid should just barely miss our planet, whizzing past while remaining out of reach. It's anticipated that the asteroid won't come any closer than 1 million miles from Earth—about five times as far as the distance to the moon, but in cosmic terms that's still quite close (NASA classifies anything that comes within 4.6 million miles of Earth as "potentially hazardous").

That said, as much as humanity lives in perpetual fear of facing the same kind of extinction-level asteroid threat that played a part in the dinosaurs' forced evolution into birds, we really shouldn't worry too much about threats like 2017 YD7.

While the asteroid would create a very pretty light show, it's by no means large enough to wipe out all life on the planet. The exact circumstances that killed the dinosaurs remains a mystery, but it probably involved a much larger rock, hitting a very specific location, to create the kind of event that would ruin our planet.

If 2017 YD7 were to collide with Earth, it's most likely that the asteroid would plop into the ocean, with minimal disturbance to us on the land.

This particular asteroid won't be seen again for a long time to come. Once 2017 YD7 grazes our planetary comfort zone, it'll be off on its travels around the solar system for the better part of a century - by which point, we can assume, humanity will have finally built our own laser defense Death Star (and possibly wiped ourselves out with it, as well).

Asteroids are not an uncommon sight in the night's sky, and even bigger rocks are seen regularly without incident. Over 2,000 asteroids were discovered last month alone, as there's so much debris and flotsam swirling around the solar system that it's hard not to spot something if you keep a close enough eye on the stars for long enough.

2017 YD7 might be a close visitor, but it's not going to be the one big rock that will put an end to humanity's time as the dominant species on Planet Earth.

Perhaps that's a shame—when the dinosaurs were snuffed out by a big asteroid, they got the consolation prize of learning to fly. There are plenty of humans who'd trade internet access for a similar perk, if only it was offered.