The annual Leonid meteor shower has long been a favorite of serious skywatchers. Last year, when it produced a stupendous storm of shooting stars, it became the doorstep-astronomy darling of the masses.

This year there are serious expectations. We want another Leonid storm!

Meanwhile, there are many plain Leonid truths. Here are some of the lesser-known facts about the phenomenon, those that might come as a complete surprise or at least prove enlightening in their full explanation:

1

Since the Moon ambles through the same region of space as planet Earth, it too is showered by small particles every November.

However, theres a difference: The Moon has no atmosphere to gobble up the grains. So the tiny bits of comet debris slam into the surface and explode.

Seismic recorders left on the Moon in the Apollo era recorded these Leonid strikes in the 1970s, and scientists first confirmed they occurred with visual observations during the 1999 Leonid meteor shower.

Last year, three separate skywatchers saw one of these lunar Leonids, using telescopes and looking for such events. They observed a brief flash of light equal in brightness to a dim star that would be visible to the naked eye under reasonably dark skies.

But how can a particle no larger than a marble and weighing only a few ounces create light visible from 238,900 miles (384,402 kilometers) away?

Scientists have figured this out in recent years: Leonids travel so fast relative to the Earth and Moon more than 160,000 mph (72 kilometers per second) that the impact per unit of mass is 10,000 times greater than dynamite. Moon dust for a few yards around the impact area is vaporized.

[Leonids Full Coverage] Next, Leonids are not what you think