Fed II Star - May 7, 2006 - Official News 9

REAL LIFE NEWS: THE MOON SKY IS FALLING

Chicken Licken should be glad he doesn't live on the moon; he'd be yelling out his warnings constantly. Meteoroids hit the surface of the moon all the time - more than a metric ton every day. They fall out of the sky and plummet down to the surface, all shapes and sizes, from specks of comet dust to huge asteroids, travelling up to one hundred thousand miles per hour.

Earth gets bombarded with just the same stuff, of course, but most of it burns up in the atmosphere and doesn't reach the ground, disintegrating harmlessly. But on the moon, there is no atmosphere to protect the world, and the meteoroids make it all the way to the ground where they impact with a helluva thud.

So if there's so much debris raining down from the skies every day, how come the Apollo astronauts didn't get brained by it? That's because the moon's surface area is roughly the size of the continent of Africa, and if you spread all of the impacts out over all that terrain, the chances of any one spot getting hit are pretty low. The crews of all the Apollo missions put together were only on the surface for a short time - less than two weeks - so that, too, shortened the odds of a meteorite landing on them.

But future plans call for NASA to send astronauts back to the moon to stay for longer, and to build permanent bases. They will be larger than before and therefore provide bigger targets. We can assume, therefore, that the odds of being hit by a meteoroid will go up.

Bill Cooke and Anne Diekmann, of the Marshall Space Flight Center's Meteoroid Environment Office are trying to find out just how much of a problem this could be. They are loading old seismic data, collected by sensors left on the moon by the Apollo missions, into modern computers to analyse the tremors. Some of them are caused by known phenomenon but others are not, and they could be meteoroid impacts.

For more information, go to the Science@Nasa web site.