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 miles across and devastate hundreds or thousands of miles around it, kick up dust and steam into the atmosphere–some would even orbit the Earth for a while. It would be a global problem.
Were you surprised by 2002 MN? After all, it came out of the blue. Not really. Statistically, there are about 50 times a year when something this size passes within a lunar distance [closer than the moon] of Earth. The problem is, we don’t usually find them because they’re so small and they don’t reflect a lot of light.
What should we do about 1950 DA? In hundreds of years, it’s hard to imagine what ways we’ll have to deal with it. It’s sort of like guys 900 years ago trying to plan the interstate highway system. It would probably be more sensible to leave it to future generations. If you have centuries of warning like this, you can just change the way it absorbs and reflects light and heat. Sunlight shines on it and heats one side, and it rotates around to the back and the heat radiates off into space and sort of pushes on it like a weak rocket. Over centuries, it’s enough to push it out of the way. If you have hundreds of years of warning, you could spread chalk or charcoal over the surface that changes the way it reflects light and its velocity, or you could send what they call a solar sail–a big sheet of Mylar-like plastic–and sort of shrink-wrap it, and the sunlight over centuries would push it out of the way.
And if you don’t find out centuries before it hits the Earth? We want to find these things as soon as possible so we have many options. If you only have a couple years’ warning, you’d have to use nuclear weapons. Right now we’re not in a position to do that. The issue of fitting nuclear weapons onto a spacecraft that can go into space and rendezvous with an asteroid–you’d have to know a lot about the asteroid to do it properly, and a couple years is really short notice.
Should we be doing more? Yeah, it’s sort of a problem here, particularly with radar. The funding particularly in radar seems to be in doubt. There have been attempts to shut down the station in Arecibo, Puerto Rico, and Goldstone in the Mojave, which discovered 1950 DA. It’s sort of a thin operation here. Radar is the only ground-based way we can have that will tell us the shape and the size and allow us to make these kinds of hazard predictions. What you want to be concerned about is things that haven’t been discovered yet.
