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NASA's New Asteroid Mission Could Save the Planet
By Tariq Malik SPACE.com Managing Editor
16 April 2010
President Barack Obama set a lofty next goal this week for Americans in space: Visiting an asteroid by
2025. But reaching a space rock in a mere 15 years is a daunting mission, and one that might also carry the
ultimate safety of the planet on its shoulders. "By 2025, we expect new spacecraft designed for long journeys
to allow us to begin the first-ever crewed missions beyond the moon into deep space," Obama said. "We'll
start we'll start by sending astronauts to an asteroid for the first time in history.“
Astrophysicist John Grunsfeld – a former NASA astronaut who three shuttle missions to fix the Hubble
Space Telescope – suggested sending humans to purposely move an asteroid, to nudge the space rock to
change its trajectory. Such a feat, he said, would show that humanity could deflect a space rock if one
threatened to crash into the planet.
Scientists estimate there are about 100,000 asteroids and comets near Earth, but only about 20,000 are
expected to pose any risk of impact. NASA has found about 7,000 of those objects, 1,000 of them flying in
orbits that could potentially threaten the Earth in the future, NASA scientists have said. Astronomer Donald
Yeomans, head of NASA's Near-Earth Object program office at NASA's Jet Propulsion Laboratory in
Pasadena, Calif., said there are about a dozen near-Earth asteroids that could be within reach of manned
spacecraft, but most of those are relatively small. To make a crewed mission worth it, the target space rock
would likely have to be at least 300 feet (100 meters) wide. For comparison, the space rock that exploded in
a magnificent fireball over Wisconsin this week was just 3 feet (1 meter) wide, Yeomans said.
But there are secrets locked away on asteroids that may hold the key to understanding the formation of the
solar system. Asteroids are the thought to be the leftover remnants of the solar system's buildings blocks.
The organic molecules and compounds on them may offer clues on how life began on Earth, and if it's
possible elsewhere in the universe.