What?

What?

Gangplank 27 Oct 2011 17:34

NASA is talking about a keyhole that apophis could hit in 2029, and if it hits it, it is going to hit in 2036.

So, would anyone please explain this keyhole? How does it exactly work?

Edit: forget this thread, I guess i should learn to use google

http://en.wikipedia.org/wiki/Gravitational_keyhole

Last edited on 27 Oct 2011 17:40 by Gangplank Show more

Re: What?

obaeyens 27 Oct 2011 17:47

So, would anyone please explain this keyhole? How does it exactly work?

It is like you trying to win the Euro millions. How many times did you win the the 40,000,000 euros?

The keyhole is a theoretical location and time, that if the asteroid would get there at that time and place within a few km or so I think, that it might get back next time and risk hitting Earth. However a very tiny deviation, no matter how small will make it deviate it and will miss Earth even further.

And here is the interesting part, if it does hit that keyhole which is very very improbably, then all we need to do is put a rocket on it, speed it up and it will completely miss Earth next time.

Re: What?

Gangplank 27 Oct 2011 17:58

Interesting. It'd be actually cool to see an asteroid being deflected.

Re: What?

obaeyens 27 Oct 2011 18:04

It is actually very hard for an asteroid to hit Earth.
Earth moves at a speed of about 30 km/s. You could calculate very easy how much time an asteroid has to hit earth at that spot. Diameter of earth in km divided by the 30 km/s and you have the time in seconds. ;-)

Most Asteroids move to fast to get captured by Earth so it must hit Earth straight on. basically a lucky shot.
And here is the interesting part, even if the asteroid hits the above atmosphere, it actually would bounce off like a stone over water. It really needs to have a straight on hit. There is no magical force that magically will pull it towards Earth.

pedro (guest) 27 Oct 2011 20:31

but im serious when I say I have read a article that NASA says they going to send a spacecraft to to apophis and move it from orbit a little not because it is a danger but they see it like a good test in the future if it comes object that can hit the earth that they see they can move it , but I dont know how much prove it is in the article