Asteroid hunt: What else is coming our way?

23.02.2007
The asteroid Apophis, named after an Egyptian god representing darkness and chaos, has, at the moment, a 1-to-45,000 chance of striking Earth in 2036. But those odds will soon change, probably in a good way for mankind, while the hunt for near-Earth objects continues.

It is an effort that involves scientists like David J. Tholen, one of the astronomers credited with finding Apophis. It also includes the planned construction of a massive telescope on a mountaintop in Chile and the creation of what may be the world's largest database. Even Google Inc. has entered the picture.

Tholen, who has a Ph.D. in planetary sciences, and his team discovered Apophis in June 2004. The asteroid has been traveling the heavens for eons, but what is alarming isn't so much the odds that it might strike Earth, but that it was only recently discovered as a possible threat.

Apophis is located in a part of the solar system that makes it difficult to detect because it travels in the daytime side of Earth. Apophis will spend 95 percent of its time on the side of the sky that has the sun in it, Tholen said. "Are there other objects like it that we haven't found yet? Almost certainly."

"Could one of those objects sneak up on us from the daytime side and smack us without us being aware?" Tholen asked. He successfully sought funding from NASA to explore those areas of space where detecting asteroids is difficult because of the sun. The only time these objects can be viewed is a couple of hours after sunset and couple of hours before sunrise. Anything visible looks more like a crescent moon than a full moon, "so the objects that you are trying to find are fainter still."

Apophis made news this month when the Association of Space Explorers, a Houston-based group that includes Russians and Americans who have flown on space missions, urged the United Nations (pdf format) to organize efforts to thwart Apophis and anything else potentially hurling this way.