Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Apophis 2036?

  1. Mar 30, 2009 #1
    I would like to hear speculation about Apophis and its possible impact with the Earth in 2036. I am particularly interested in whether earthlings can change the orbit of Apophis if we need to. Is it possible to rendezvous with an incoming asteroid? How fast is this asteroid traveling?
  2. jcsd
  3. Mar 30, 2009 #2
    I don't mean to completely discredit apophis but I thought that it was deemed that apophis had a 1/12 million chance of catching the "gravitational keyhole" in 2029 that would set up a collision, thus rendering it a 0 on the Torino scale. I do remember roughly two years ago this seemed to be a hot topic. I think apophis was a 4 on the Torino scale at one point, for what it's worth.

    this website seems to be a credible source, and is a pretty interesting read

    Last edited: Mar 30, 2009
  4. Mar 31, 2009 #3


    User Avatar
    Science Advisor

    As far as altering the path of apophis, assuming an initial impact trajectory, it is very difficult. All the methods I've heard described (nuclear weapons, attachment of rockets, gravitational redirection) are either impractical or simply do not work. Looks like apophis has an average orbital velocity of ~30km/s, coupled with a mass of about 10^10kg, the thing is damn hard to move.

    Edit: Ignore this in light of what Hurkyl pointed out. Didn't read the above article.
    Last edited: Mar 31, 2009
  5. Mar 31, 2009 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    This directly contradicts the link given by the previous poster, which states that simply placing an 8 kilogram, 17,000 square foot reflective "sheet" on the asteroid would be enough to deflect it over 4000 miles.
  6. Mar 31, 2009 #5
    At 30 km/s, is it possible to land on Apophis and place reflective sheets there?
  7. Apr 2, 2009 #6
    Your own source says "less than 1 in 45,000," which is many orders of magnitude more likely than "1/12 million."
  8. Apr 3, 2009 #7


    User Avatar
    Science Advisor

    Once you have matched speeds with it, its (relative) speed is 0. That has nothing to do with how difficult it is to land on it.
  9. Apr 4, 2009 #8

    Glad you read it. Thanks for pointing that out...
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Apophis 2036?