Earth Impacts IV
A small space telescope was recently awakened from a long sleep to get back to work. Its new mission: to look for asteroids that come close to Earth’s orbit around the Sun. Some of these space rocks could endanger our planet — a collision with even a fairly small asteroid could have devastating effects.
Astronomers have discovered more than 10,000 asteroids that approach Earth’s orbit. Of those, about 1400 have some risk of eventually hitting us. Hundreds or thousands more of these potentially hazardous asteroids may await discovery.
It’s important to find them all, because with enough warning time it might be possible to deflect an asteroid from a collision course. So several automated telescopes hunt for asteroids every night.
And last September, the space telescope joined the hunt, too. WISE was designed to map the sky at infrared wavelengths, which are blocked by Earth’s atmosphere. It discovered cool stars, brown dwarfs, distant galaxies, and many other objects — including about 135 near-Earth asteroids.
WISE was shut down in early 2011. The craft can no longer peer into deep space, but it can still hunt for nearby asteroids, so it was switched back on. In the coming months, it could find another 150 of them. It’ll also provide more details on a couple of thousand that are already known. Its work could help defend Earth from future threats.
More about defending Earth tomorrow.
Script by Damond Benningfield, Copyright 2013
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