Tuesday, August 11, 2009

Falling stars

How do we gather the stuff of the universe for study here on Earth?

The StarTrek method: Go where no one has gone before. Apollo astronauts brought back buckets of rocks from the moon. Three Soviet unmanned Luna missions also returned lunar rocks to Earth. The method is expensive, which explains why round-trip missions to the moon or other celestial bodies have been rare.

The cheaper method: Let the universe come to us. The turn-of-the-century naturalist John Burroughs felt no need to travel; sooner or later, he said, the turning Earth brought everything by his door. The same apparently applies to those scientists who study the stuff of the cosmos.

Each year, tens of thousands of tons of meteoric material fall upon the Earth from space. Most of this material is in the form of small particles that burn up in the upper atmosphere. Occasionally a meteorite arrives that is big enough to blast a huge crater and cause mass extinctions.

Most interesting from the scientific point of view are those meteorites that are large enough to survive the plunge through the atmosphere, but not large enough to be devastating. These collectibles from the sky are messengers from the world beyond.

They come from Mars, from the Moon, from the asteroid belt, and even from beyond the solar system.

It turns out that finding and collecting meteorites is quite a story in itself, a story that my friend Chris Cokinos tells in his just published book, The Fallen Sky: An Intimate History of Shooting Stars. I had the pleasure of reading the book in manuscript, and here is the comment I offered, which I notice Chris' publisher has used on Amazon:
Christopher Cokinos goes from pole to pole in his search for the bits of cosmos that fall onto the Earth, and the remarkable people who collect and study them. He is a natural philosopher and gifted writer who sprinkles his own kind of stardust on every page. If you have ever wished upon a falling star, this is your chance to know just what is falling, where it comes from, what it tells us about our place in the universe -- and what things in life are worth wishing for.
We learn too about Chris Cokinos and the passion that drives a poet/naturalist to spend years of his life on a single-minded quest for chunks of rock and iron from the sky.