Mon February 14, 2011
Inquiring Minds - Near Earth Objects
By Bonnie Stevens
Flagstaff, AZ – Rocks the size of living room furniture sail past us every week. . .so close, they're called Near Earth Objects. If they make it to Earth, astronomer David Trilling wants to be there to pick up the pieces.
This is Inquiring Minds. . .insights from the campus of Northern Arizona University.
The asteroid that struck the Earth some 65 million years ago put an end to the age of dinosaurs. An iron nickel rock only 50 yards across caused the mile-wide hole in the desert known as Meteor Crater.
The bigger the asteroid, the less likely it is to strike the Earth. Huge, life-changing impacts happen only every 100-million years or so.
Still, the thought of asteroids falling from the sky can be alarming to those of us on the ground. . . so there's a whole network of astronomers like David Trilling who track them.
But, David Trilling says asteroids the size of a sofa are being flung at us all the time. Most of them burn up in the atmosphere. Anything left over becomes a pile of rocks or splashes by unnoticed in the ocean.
That's a shame, says Trilling, because these space visitors have a lot to tell us . . .a story about the conditions of our solar system when it was forming four-and-a-half billion years ago.
But tracking an asteroid on a collision course with Earth, predicting its descent, and finding that pile of rocks is hard to do. It's only happened once.
In 2008, astronomers traced a Near Earth Object to Africa. This asteroid was made out of a gray volcanic material, easy to find in the desert of Sudan.
Trilling says thoseasteroid pieces can then be compared with what we see through telescopes, for a more comprehensive view of what's in space.