Remember our old friend 2004 MN4? You know the one -- it had astronomers reaching for the antacids because, unlike every previous "Earth-crossing" asteroid spotted, the chances of it hitting the Earth increased the more they studied its path. Fortunately, they finally determined that it would miss us in its very close pass in 2029. But it turns out that it will be close enough to be visible from the ground as it shoots by -- so close, in fact, that it will pass within the orbits of some satellites. This will be the closest known approach by an asteroid in history, roughly 22,600 miles from Earth. It should be as bright enough to be seen by the naked eye in Europe, Africa and parts of Asia -- but only in locations with dark skies.

Mark your calendars now.