It Came From Outer Space.(Jon D. Giorgini on astroids)(Brief Article)(Interview)

Jon D. Giorgini says he isn't losing sleep yet over 1950 DA, the kilometer wide asteroid that he predicted in April might collide with the planet Earth. After all, if it hits, it won't get here for 878 years. But that doesn't mean we should let our guard down. If anything, Giorgini, a senior engineer at NASA/Caltech Jet Propulsion Laboratory in Pasadena, California, says his recent study shows Earth is vulnerable. That point was driven home again last week, when rival researchers at MIT's Lincoln Laboratory spotted a chunk of space rock-- about the size of a football field--whizzing by Earth just 75,000 miles away. Named 2002 MN, it came closer than any similar-size asteroid had in recent years. Giorgini spoke with NEWSWEEK's Adam Piore last week. Excerpts:

PIORE: How many people are involved in this type of research?

GIORGINI: It's sort of a golden age of discovery for asteroids. Between one and 5,000 are being discovered each month because we have new automated systems which are coming online and are able to scan the skies in an automated way due to new software and hardware. We've begun to recognize the threat because of these objects. But the total number of people is about the same as a McDonald's store: a couple dozen people, at most, working on this on an active basis. There isn't a lot of funding for it.

Is this something we should be worried about?

Well, not this particular asteroid, 1950 DA, because it's so far off. It's 878 years in the future, but it's possible that there are other asteroids we haven't discovered yet that could impact sooner. The purpose is to find these things as soon as possible. If there are centuries of warning, there are many things you can do about the threat. But if you only find out about it in the last day or two, or the last year, there's not much you can do. As far as last week's asteroid goes, it was a close approach--one of the two closest we've seen, but it doesn't look like it's an impact threat right now.

What would happen if one of these things hit?

There was an incident where an asteroid comparable to 2002 MN hit in Tunguska, Siberia, back in 1908. It exploded in the air and flattened about 800 miles of forested area. This object here we're talking about is 50 to 100 yards across. It would be about 10 times bigger than a nuclear explosion. The thing is traveling around 23,000 miles an hour, so it's got a lot of energy. 1950 DA would carry about 100,000 megatons of energy if it hit. It would make a crater about 10 to 15 ...