Asteroid + Earth Impacts: rising probability... 4142

Straydog

"Stardust" pbutted by Comet Wild 2 early last year and took photos, some of which were published. "Deep Impact" also took pictures of Tempel 2.

Although comets do not have the same orbits as asteroids, the type of trajectories are similar. By changing the parameters, one can get orbits for one or the other.

Comets aren't as rare as most people think. Many appear once and end up colliding with the sun as the "SOHO" probe found over the last few years.

Certainly we don't know right now what to do with a piece of space rock or ice that's got us in its sights, but, over the years, several spacecraft have flown past comets and "NEAR Shoemaker" flew to, orbited, and then landed on the asteroid Eros about five years back.

We have, therefore, the means by which to deliver something to such bodies. What to do once it gets there has yet to be determined.

That's because there are several different types of asteroids, just as there are meteors (which are often a result of a comet breaking up). What comets are made of is still the subject of debate, but the results from "Deep Impact" may give us a clue as will "Rosetta" when it lands on its target comet in a few years time.

That's possible.

There are far more being found now through terrestrial observation satellites. A number of geological features are now attributed to such impacts after having been mapped from orbit, even though they've been subject to erosion.

What the Tunguska event was is still the subject of debate. Some suggested it was a UFO, but nobody has admitted to having found any debris. It's largely believed to have been either a comet or a meteor which exploded well above ground, resulting in the devastation.

Comet Shoemaker-Levy 9 in 1994.

Actually, we're not sure what damage such a collision might cause. The comet fragments impacted on Jupiter's atmosphere, which, of course, isn't solid.

If the impact zone can even be determined that accurately. When the first Shoemaker-Levy hit Jupiter's atmosphere, the general feeling was that collisions wouldn't be seen. Instead, they could be observed while they happened by the Hubble Space Telescope.

It may not even require nukes. A kinetic kill warhead, similar to "Deep Impact" might be sufficient to break it up, but that might make things worse. A better approach would be to land a propulsion module on the body and then ignite it to change its velocity which will, correspondingly, change the trajectory.