NASA plans mission to visit asteroid

It may not rank as thrilling as putting an astronaut on the moon but it's still a heady proposition: NASA intends to send a space probe to a distant asteroid that will be able to scoop up a dirt sample without landing and then return to Earth.

All by September 2016. That's when the OSIRIS-REx1 spacecraft is slated to lift off, en route to intercepting asteroid 1999 RQ36. After a year's orbit spent photographing the asteroid and measuring its surface topography, composition, the probe will descend toward the asteroid at 0.2 mph, getting close enough to extend a robotic arm that will will scoop up dirt samples without requiring the craft to land.

Based upon their previous ground-based telescope observations, scientists believe that asteroid 1999 RQ36 is rich in carbon-based compounds. That's where the questions begin and NASA's hope is that some of the materials brought back from the asteroid can shed light on life's origin on Earth.

The exercise has another purpose as well.

Astronomers have been investing their effort in exploring ways to divert so-called near-earth objects from smacking into Earth. Until now, that's been the stuff of Hollywood movies, such as the the film Armageddon, where a deep core drilling team from Texas is sent to destroy a civilization-threatening asteroid with a nuclear weapon. However, a program is already underway at the European Space Agency to learn more about how Earth can defend itself against the potential threat of a future asteroid collision. The ESA's Project Don Quixote is supposed to get underway one year earlier than OSIRIS-REx1, and involve a couple of spacecraft in a test to determine whether a near-Earth asteroid can get diverted.

Similarly, OSIRIS-REx will help NASA learn how to navigate close to an asteroid, preparing for the day when the agency decides to actually land on one.

"We're the first species that can mitigate asteroid extinction," notes Michael Drake of the University of Arizona. "With enough information, we can project the orbit of a threatening asteroid."