Talking outer space with a pro

University of Arizona astronomer Ron Fevig is an expert on near-earth asteroids. He also has roots in the Old Country (my father went to daily vacation Bible school at the same church as his mother), which led him to this weblog, which resulted in us having lunch this afternoon.

Naturally, I was full of questions. Ron studies the light which reflects off asteroids in order to discover the chemical composition of the surface of the asteroid. That chemical composition tells a great deal about the history of each particular asteroid.

But Ron had to start with the basics for me. Asteroids are chunks of rock which orbit the sun but are too small to be classified as planets. They range from tiny chunks of rock to one which is 200 miles across. They originate in the "asteroid belt," which lies between Mars and Jupiter. That belt may be a planet which disintegrated in big collision, but researchers aren't sure.

Most of the asteroids stay in that belt. They orbit the sun on roughly the same plane as the planets, and in the same counter-clockwise direction (if you were standing on the north pole of the sun). Where things get complicated is when some of the asteroids get thrown into an unstable, or very eccentric elliptical orbit by the gravitational influence of a planet, such as Jupiter, or by a collision, or by other forces. Such asteroids can actually cross into the earth's orbit and could pose a threat to life on earth if they were to crash into our planet.

So, I asked Ron, is everything in the solar system on a flat plane? All the planets and the asteroids? I had imagined the planets whirling around the sun from all different directions. In fact, Ron said, they are all on roughly the same plane, although the orbit of Pluto (which Ron argues might not really be a planet) is off by 20 degrees. Asteroids, like Pluto, are not so strictly limited to the plane (called the ecliptic). Some of their orbits deviate as much as twenty degrees from the ecliptic as well.

However, comets are a different animal. They come in from way, way out, from a spherical orb of ice chunks which surrounds the entire solar system about 100,000 times as far away from the sun as the distance from the sun to the earth. Some of those chunks are on orbits which take thousands of years to complete--and are at this moment moving at slow speeds, unseen, undiscovered, unlit, out on the edge of solar system, where the sun's gravitational influence is nearly equalled by the influence of the next nearest stars.

Ron showed me a computer he uses to track man-made satellites. I found out that the Hubble telescope, probably the most famous of the 10s of thousands of man-made satellites orbiting the earth, was passing through the Arizona skies just after sunset tonight. It would take all of a few minutes to cross the Arizona sky, so you couldn't blink or you'd miss it.

Ron took me for a tour of the NASA Regional Image Library, where the public is free to view thousands of pictures taken from the earliest NASA missions to the most recent. The curator pulled out a photo album containing some of the photos taken on Apollo XIII. It was eerie to see the pictures of those astronauts, who were exhausted after nearly losing their oxygen supply, displayed in what could have been a family photo album. I plan to return to do some digging.

We went to the lab where Ron is working on a tiny cube which will be sent into space to orbit the earth next fall for the purposes of communication. It is about six inches square, but contains computer chips which will be powered by tiny solar panels. It was sitting on the table, looking much like the innards of a small television. We did not play catch with it.

The research project has rented space on a former Soviet ICBM to send the tiny cube into space. The cost? About $10,000 per pound. That's the going rate for postage into space. The Russians are retooling their old nuclear missiles to take payloads into space--they need the hard currency, after all.

So, a fascinating day. What a pleasure to hear somebody talk about their passion--especially when it is a topic which interests me to no end.