But how often do you actually get to see such things, unless you spend time looking in a telescope? When does the average person get in on the fireworks?

Well, there is a written record of five average guys - -British monks, in fact -- who, on a June evening in 1178, happened to be watching when something astounding happened on the moon. In their records they wrote that the upper horn of the new moon "broke in two" and emitted a "flaming torch" full of "hot coals."

The hand of God? More likely an asteroid collision, say modern astronomers.

The description of the blast matches our prediction for what a lunar impact would look like from earth. But is there any other evidence? The moon has been battered by asteroids for millions of years, as its scarred surface demonstrates. If an asteroid hit it as recently as eight hundred years ago, a crater should be quite apparent. And indeed, the crater Giordano Bruno -- named after the 16th century scholar -- is in the spot where the impact would have to have occurred to cause the sight recorded by the monks.

More compellingly, this crater still has visible rays -- streamers of fine dust that extend out from its center. Because these dusty rays disperse with time, their existence suggests a collision of relatively recent origin.

Not all astronomers agree with this interpretation, and it would take another trip to the moon to date the crater accurately. But the possibility is an intriguing one.  

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