Earth's Second Moon

[ydoaPs]

http://www.fuchsiashockz.co.uk/articles/astro/Cruithne%20Earths%20second%20moon.shtml

[MolecularMan14]

Thats kinda strange. I would like to see it up close.

http://burtleburtle.net/bob/physics/cruithne.html

That last diagram makes me wonder if it will ever come a little too close to earth!

[5614]

this is testing the definition of the word 'moon', i think that looking at the articles it is just a comet which passes by us and the gravitational fields of the earth/comet slightly effect each other, not like a moon... looking at the last diagram on molecularman's link, the comet clearly goes around the sun, however crosses over near the earth, thus a slight 'interaction', as this comet cannot be seen by the naked eye i doubt theres a chance of it crashing into us!

[ydoaPs]

i was thinking the same thing

[Sayonara]

Old.

[philbo1965uk]

would be wouldnt it.i thought flamin and spam was not allowed

[Caustic]

what exactly is a "horseshoe" or "tadpole" orbit anyways?

[Sayonara]

would be wouldnt it.i thought flamin and spam was not allowed

No, old as in "so old there was a thread about Earth's third moon candidate years ago".

http://www.scienceforums.net/forums/showthread.php?t=274

 

 

And you're right, flaming and spamming is not allowed. Neither is trolling for responses.

[pi_of_9]

what exactly is a "horseshoe" or "tadpole" orbit anyways?

 

I believe it describes the shape of the orbit. The object in a horseshoe orbit does not move around a central point in a circle or ellipse but swings somewhat like a pendulum. I have also seen reference to a Tulip orbit. Although, this was in a book written about the Nemesis Star and was theoretical.

[5614]

indeed so, 'tadpole' is like the shape of a tadpole! long and thin,

 

so it is close to escaping the thing its orbitting, but then slowly loses its velocity due to the gravitational pull of the thing its orbitting, and shoots back towards the object (generally missing it!) it then carries on way past the orbitted object using its just gained velocity and so the cycle begins again... (just thats 1/2 of it, the other 1/2 is exactly the same).

 

not quite sure how a horseshoe shape would occur, presumably with more than one plannet or something, as a horseshoe has a straigt edge... maybe its approximate.