KNAU and Arizona News
Thu February 27, 2014
Brain Food: Bagging an Asteroid
NASA wants to catch an asteroid, place it into orbit around the Earth, and send astronauts to retrieve pieces of it for scientific study. The agency just needs the right asteroid. NASA has asked Northern Arizona University astronomer David Trilling, one of the world’s foremost asteroid experts, to find it — a task much easier said than done.
“You have to have an asteroid whose orbit is just right that you can get to it. And the way they want to capture this thing is they want to send a spacecraft and then put the asteroid in a bag and then they bring it back. Well, the bag is only so big, so if the asteroid’s too big, it doesn’t fit, no good,” Trilling says.
The right fit is about the size of a school bus, says Trilling, similar to the meteor that surprised Russia about a year ago. To avoid being surprised again, Trilling and others survey the sky every night for asteroids that could be on a collision course with the Earth.
“There are about 10,000 known near-Earth asteroids … and most of those are big, big is bigger than the Skydome, let’s say, and none of those right now have any chance of hitting the Earth. The problem is there are many, many, many thousand more asteroids bigger than your car that are near the Earth; we don’t know where they are and we have no idea what their risk of hitting the Earth is,” Trilling says.
Trilling, an associate professor of physics and astronomy, has developed a technique for measuring asteroids. In fact, he and the astronomy team at NAU are the only scientists in the world with the knowledge and resources to do this. So NASA’s relying on them.
“It’s like catching a baseball. You’re playing outfield for the Diamondbacks and somebody hits a fly ball to the far outfield and you have to run back towards the fence and look over your shoulder and hold out your glove and catch this thing as it drops in,” Trilling says.
If an asteroid is coming our way and we want to change its path, Trilling says this NASA mission would give us good practice.