133. On Friday 10th November 2084, the transit of Earth from Mars will occur where the Earth will cross between the Sun and Mars which will obscure a small part of the Sun's disc for an observer on the Red Planet. No one has ever seen a transit of Earth but if NASA's plans to get people to live on Mars by the 2030s goes ahead, this could be possible for the next such transit. This will be the only time the phenomenon happens in the 21st century, with the next one predicted for 2394. And by then, we should have definitely colonised the Red Planet!
