Could spacecraft be used to deflect an asteroid?
A listener wrote, “What are scientists doing about the possibility that a large asteroid might strike the Earth?”
Earth & Sky spoke with Donald Yeomans, manager of NASA’s Near–Earth Object Program, which coordinates several scientific groups that scan the skies routinely with large telescopes, while tracking the orbits of asteroids.
Yeomans said that an asteroid might be safely deflected from Earth’s path.
Donald Yeomans: For example, the Deep Impact spacecraft, we just showed, rather dramatically, that we can autonomously collide a comet with a fairly heavy spacecraft . . .
But the key would be to detect the asteroid early enough, decades before it had time to impact Earth.
Donald Yeomans: It only takes a fraction of a centimeter per second to change that object’s velocity, and it can be done with a fairly modest–sized spacecraft.
There’s geological evidence of massive asteroid strikes in the past, such as one 65 million years ago thought to have triggered the end of the age of dinosaurs. The dinosaurs had no way to prevent that ancient asteroid impact, and today, in our human world, it’s different. Scientists have established programs whose aim is to protect us from a killer asteroid.
Our thanks today to Research Corporation, a foundation for the advancement of science.
It is key to realize that, although a spacecraft like Deep Impact could be used to ram an asteroid that was on an Earth–threatening trajectory, this attempted deflection of the asteroid would have to be done a few decades in advance of the predicted impact. It would be much more difficult to deflect an asteroid whose collision with Earth was imminent. However, no imminent collision is expected.
Click here for an interview with Don Yeomans.
Read an upcoming Earth & Sky radio program about the anticipated approach of Asteroid Apophis.
Our thanks to:
Donald Yeomans
Manager
Near Earth Object Program Office
Jet Propulsion Laboratory
NASA
Pasadena, CA
D.C. Agle
Media Relations Specialist
Jet Propulsion Laboratory
Pasadena, California
