Working at an observatory, perhaps the question I’m asked most frequently is whether or not I’ve seen anything strange in the sky. By strange, they usually mean alien spacecraft or something coming down from the heavens to threaten life and limb. I can honestly say I’ve never seen an alien spacecraft, but this past week I did work with a pair of astronomers whose job it is to watch for asteroids that provide an all too real threat from above.
The astronomers work for Spacewatch, a group at the University of Arizona’s Lunar Planetary Lab whose job is to search for and study the various populations of small objects in the solar system. In the photo above, the two Spacewatch telescopes on Kitt Peak are in the two foreground domes. One contains a 0.9-meter telescope. The other contains a 1.8-meter telescope. Although great telescopes, they aren’t quite large enough to see the smallest or most distant objects. Every now and then the Spacewatch team gets time on the 4-meter telescope, the big one on the top of the hill, which I operate.
At this point, I don’t know of any objects definitely destined to strike the Earth. Back in 2013, I did help an observer use the Kitt Peak 2.1-meter telescope watch as an asteroid called 2012 DA14 pass near the Earth. At that point, it was the closest observed approach by an asteroid of that size. Meanwhile, on the other side of the Earth, a meteor that no one had observed previously struck Russia. It was one of the most amazing coincidences imaginable and and a reminder of how much work is needed to catalog the small objects of the solar system.
An asteroid strike is a very real and terrifying idea. At this time, we have no way to defend against such a possibility, and even if we could defend ourselves, we still have a lot to learn about exactly what is out in space. A few years ago I wrote a story called “An Asteroid By Any Other Name” which imagined an asteroid-hunting team in the future identifying an asteroid on a collision course with Earth. Although they successfully destroy the asteroid, debris rains down on the jungles of the Amazon. The real problems start when the asteroid remnants start to move on their own, devouring the plant life.