[dreadgeek]

As Phil Plaitt points out in this article, every year around this time people start spreading this Internet meme that Mars will look as large as the Moon in the night sky. It's a hoax. It will always be a hoax because Mars *never* gets close enough to Earth to look as large as the Moon. At its closest pass Mars gets within 35 million miles of Earth. At its farthest point (where it is now) it is about 210 million miles from Earth (it's currently on the far side of the Sun from us). Mars is a relatively small planet. It is half the size of Earth. The moon is about half the size of Mars. The moon is just next door (250,000 miles) compared with with the 35 million miles between Earth and Mars at their closest. So in order for this meme to be true, an object only twice the size of our moon would have to appear to be the same size even though Mars is two and a half orders of magnitude farther away from Earth! That's not optically *possible*. With the naked eye Mars can only ever look like a tiny dot in the sky. If it ever *were* in an orbit that would make it look the same size as the Moon that would be a very interesting day on Earth (interesting, here, in the "Oh God, Oh God, we're all gonna die" sense).

So if you see a meme on Facebook telling you that if you go outside sometime in the next week it'll appear as if the planet has two moons, know that someone is pulling your leg because they are.

Cheers
Aj