Protection Schemes
 Hundreds of asteroids follow orbital paths that approach or cross Earth's orbit, making them potential hazards to our planet. An impact by a large enough asteroid could devastate a city, a region, or the entire planet. Astronomers are trying to locate and track all the hazardous asteroids, while other scientists are devising schemes for deflecting asteroids from collision courses. This image shows one Near-Earth asteroid, 433 Eros, in a 2000 image from the NEAR spacecraft. [Credit: NASA/JHUAPL]
In reality, though, protecting Earth against an asteroid is likely to be more mundane. It'll take months or years of preparation, and the deflection itself could take years more. And it might not even require a big "boom."
In fact, a big boom might be the worst thing you could do to an asteroid. Nuclear missiles might shatter it into several big pieces, spreading the destruction over a larger area when it hit Earth.
It might be better to explode the nukes in front of the asteroid instead. That would vaporize some of its material -- in effect, creating a big rocket engine to deflect its course a little bit.
It might be better still to plant some rocket engines on the asteroid and push it off its collision course, or even paint its surface to make it absorb or reflect more sunlight.
All of these techniques will require years of advance warning, though. And most will require detailed knowledge of the threatening asteroid. But two astronauts have devised a technique that would require very little information about the asteroid. We'll talk about that tomorrow.
Script by Damond Benningfield, Copyright 2006
For more skywatching tips, astronomy news, and much more, read StarDate magazine.
|
Contact | About | Friends of McDonald | Sign up for Sky Tips
