Nice member name/question combination, BTW.

Are you “from Mars” then?

Seriously, though, questions like these make me wonder how many people have any real sense of the emptiness of the Solar System. (That is, planetary widths versus their average distances to the sun, and mutual separations, especially minimums.)

Recently I calculated the likelihood that a comet crossing the earth’s orbit would strike the earth. By “crossing” I mean that it is neither too far “north” or “south” of the elliptic. (These other possibilities alter the question of probability, but let’s say that we know ahead of time that the comet won’t miss the earth either such way.)

Now, I don’t remember the exact figure, but it was in the neighborhood of 60,000 to one. That’s based on the diameter of the earth versus the length of its orbit, and projecting that the comet is exactly on the ecliptic. I realize that the earth’s gravitation would affect the comet’s orbit as it approaches, but I’m figuring that it would be equally likely to cause the comet to just miss as pull ity in.

Now, the orbit of the earth is wider that that of Venus by about a 4 to 3 ratio. This is partially offset by Venus’ smaller diameter, but not by much. More significant is that the moon has a diameter that makes a difference, whereas a comet has a compact nucleus so small as to be negligible. We could almost just as soon imagine a mathematical point striking the earth as a comet.

Again, to make a realistic projection we must take into account the north/south factor. Now,if the moon is fleeing its orbit from the earth, we need not quite extend the question of a full sphere of Venus’ orbit versus the cross-section of Venus; it would be somewhere in between, and much closer to a circle-comparison than a sphere-comparison.

Bu the ratio would be pretty huge, and the probability extremely low.