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Space Science

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."
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Asteroid Once Seen As Dangerous Offers Chance For Close Study

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  • by sznupi ( 719324 ) on Monday January 31, 2011 @02:28PM (#35058794) Homepage
    The speed, relative to Earth, during the encounter will be quite high - so a probe / lander / etc. allowing for really close study would need to get quite a kick from its rocket. And very rapidly (basically ruling out more efficient means of propulsion, those tend to have very low thrust) Probably much larger than sending it to some more optimal (regarding transfer orbits and delta-v) targets, a thing ... which we are already doing!

    If it turns to be practical, another nice target is good to have of course.
  • by sensei moreh ( 868829 ) on Monday January 31, 2011 @02:29PM (#35058802)
  • by Nyeerrmm ( 940927 ) on Monday January 31, 2011 @02:44PM (#35058960)

    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)

    by Covalent ( 1001277 ) on Monday January 31, 2011 @02:59PM (#35059136)
    Hard to do! It's speed is about 31 km/s...geosynchronous orbit is more like 3 km/s. So delta V is about 28km/s...for an asteroid with a mass of 2.7×10^10 kg, that's a kinetic energy of about 1E19 J or around 2.5 billion tons of TNT (2.5 gigatons). Yeah...that's a lot.

Some people manage by the book, even though they don't know who wrote the book or even what book.