Cruithne is an asteroid in orbit around the Sun in 1:1 orbital resonance with that of the Earth. It is a periodic inclusion planetoid orbiting the Sun in an apparent horseshoe orbit. It has been called "Earth's second moon", although it is only a quasi-satellite. (wiki)
>> ^gorillaman: Which is why, in the next series, they asked the same question and gave a penalty for the answer '2'.
That's not why. It's because they'd discovered three more in the meantime, so the new correct answer was five. Stephen Fry also acknowledged that some don't consider the others as proper moons, "so you could argue that there's one, or that there's five, but certainly not two, I'm afraid." He also insists that they go around the Earth, not just that they go around the sun at the same cadence as the Earth as Rasch (and perhaps Wikipedia, but I haven't checked) suggested.
Ahh you got me I never look at details that does reduce the chances a bit.
Even if you consider the orbits to lie in a plane, the chances of an impact are virtually zero. Its orbit has evolved over millions of years through tidal forces to resonate 1:1 with Earth's orbit. This means that it takes one trip around the Sun for every trip we take, and that the orbit hardly deviates from its set path. There is some deviation, but this is very well understood and not enough to warrant concern.
Stumble This
http://upload.wikimedia.org/wikipedia/commons/2/23/Orbits_of_Cruithne_and_Earth.gif
oh well.
^ possibly, but remember that space isn't two-dimentional.
Ahh you got me I never look at details that does reduce the chances a bit.
Which is why, in the next series, they asked the same question and gave a penalty for the answer '2'.
That's not why. It's because they'd discovered three more in the meantime, so the new correct answer was five. Stephen Fry also acknowledged that some don't consider the others as proper moons, "so you could argue that there's one, or that there's five, but certainly not two, I'm afraid." He also insists that they go around the Earth, not just that they go around the sun at the same cadence as the Earth as Rasch (and perhaps Wikipedia, but I haven't checked) suggested.
I prefer the "bean shaped orbit": http://upload.wikimedia.org/wikipedia/commons/c/c7/Horseshoe_orbit_of_Cruithne_from_the_perspective_of_Earth.gif
>> ^rasch187:
^ possibly, but remember that space isn't two-dimentional.
Ahh you got me I never look at details that does reduce the chances a bit.
Even if you consider the orbits to lie in a plane, the chances of an impact are virtually zero. Its orbit has evolved over millions of years through tidal forces to resonate 1:1 with Earth's orbit. This means that it takes one trip around the Sun for every trip we take, and that the orbit hardly deviates from its set path. There is some deviation, but this is very well understood and not enough to warrant concern.
^ possibly, but remember that space isn't two-dimentional.
That was the easy answer...for full points, how many dimensions is space?
Whoah that thing is going to hit us one day dont you think?
It already has.
It was drinking and we were trying to stop it from hitting mom.