Guest Blogger Laurie Leshin: Messengers from Space – Friend or Foe?

by Michael Mullaney on February 15, 2013

(In the wake of this morning’s headlines about a meteorite blast in Russia, the Institute’s own Laurie Leshin, dean of the School of Science and space science rock star, wrote this post for The Approach. Enjoy!)

This morning people in Russia got a loud reminder that Earth isn’t really a blue marble floating peacefully in space. A meteor, about the size of a bus, slammed into our atmosphere going over 30,000 miles per hour. This caused very loud sonic booms which damaged buildings and injured about 1,000 people near the city of Chelyabinsk. Luckily, there weren’t any deaths, and damaged buildings can be repaired. But this cosmic intruder reminds us that in fact we live in solar system filled with space debris -Earth collects 40,000 tons of it EVERY YEAR. Most of it looks the above picture.

The image is of a small dust particle (about 10 microns across, or one-tenth the width of a human hair) that is slowed down in the upper atmosphere and harmlessly floats to Earth. Walk to your car, and you’ll step on lots of them.

But there are bigger things out there, too. We need to find them and then figure out how to deflect them or change their course, before a large one hits Earth. Most people have seen the really entertaining movie Armageddon, starring Bruce Willis as a driller who saves the earth from an asteroid “the size of Texas.” Well, the truth is that it doesn’t have to be the size of Texas to be a global killer. (In fact, the largest known asteroid is only about one-third the size of Texas. Hollywood!) The asteroid that killed the dinosaurs was, in fact, only about the size of our own city of Troy. And there are lots of those. Nervous yet? Me too. How about putting some of our science and engineering talents to work figuring out how to deflect one? In the meantime, remember, we live on a space rock. And sometimes, we interact with other space rocks.

By the way, I would be remiss if I didn’t mention that space rocks are good for more than scaring us. They are a boon to science. Meteorites (and I bet they’ll find some from the event of this morning) tell us about the very birth of our solar system. Most are 4.6 billion years old, and were the very first solids to form in our solar system. They bore witness to the birth of the planets and may have delivered the raw ingredients for life to the early Earth.

(Click here, here, and here to read more and see a video about Dean Leshin’s space research and work as part of the Mars rover Curiosity team.)