Asteroid Once Seen As Dangerous Offers Chance For Close Study 122
RedEaredSlider writes "An asteroid that once was seen as a danger to the Earth may soon provide a once-in-a-century opportunity to get a close look at one — and learn more about the ones that really are a hazard. The asteroid is called Apophis. It's a near-Earth asteroid that is a type called a chondrite, essentially a stony body that has high silicate content and few metals. It is about 330 meters across, and it's due to pass the Earth in 2029."
Not too much of a difference... (Score:5, Informative)
If it turns to be practical, another nice target is good to have of course.
Re:How do they know the content (Score:3, Informative)
Re:How do they know the content (Score:5, Informative)
We have a good idea of the composition of asteroids in general, from meteorites, planetary formation models, etc.
We believe Apophis is chondritic because based on its apparent brightness and the way that brightness varies, we have a decent estimate of its size and albedo. If it had a different albedo it would indicate a different composition.
Of course, as with all remote observations based on a lot of educated guesses, there is a chance its wrong. However, if it is its probably a pathological case we could never gotten right, and that would make it even more interesting to visit.
Re:Capture it! (Score:4, Informative)