dcsimg
ADVERTISEMENT
See Inside June 2010

Asteroid Collision

An extinction-level event is unlikely, but "airbursts" could flatten a city

On June 13 an asteroid called 2007 XB10 with a diameter of 1.1 kilometers—and the potential to cause major global damage—will zip past Earth. As far as near-Earth objects go, it will pass, fortunately, pretty far, at 10.6 million kilometers, or 27.6 times the Earth-moon distance. Indeed, no giant asteroids appear poised to rewrite history any time soon. The bad news is that we can expect in the next 200 years a small space rock to burst in the atmosphere with enough force to devastate a small city.

A near-Earth object (NEO) is an asteroid or comet that comes within 195 million kilometers of the planet. In 2009 NASA tallied 90 as approaching within five lunar distances and 21 within one lunar distance or less. NEO hunters typically detect them as specks on images, and such momentary glimpses can make their orbits hard to calculate. So researchers can only lay odds of an impact as they await more data. NASA has spotted 940 NEOs one kilometer or more in diameter (about 85 percent of the estimated total of that size), and none will collide with Earth. (The NEO that wiped out the dinosaurs was about 10 kilometers wide.)

This is only a preview.
Get the rest of this article now!

Select an option below:

Customer Sign In

*You must have purchased this issue or have a qualifying subscription to access this content


It has been identified that the institution you are trying to access this article from has institutional site license access to Scientific American on nature.com.
Click here to access this article in its entirety through site license access.

Rights & Permissions
Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
ADVERTISEMENT