NASA Plays Well With Comets

jmichaelg writes "Taking a page from Hollywood, NASA approved a Deep Impact mission to poke a seven story hole into Comet Tempel 1. It's a little tough to get past the grandstanding on NASA's part - the collision is scheduled for July 4, 2005. OTOH, hitting an asteroid something NASA has to demonstrate they can do. They missed on their first attempt at an asteroid rendezvous and spent a year chasing Eros. Clearly, they need a bit of practice. Last year, Los Alamos Labs detected two meteors impacting the earth. The bigger of the two explosions was estimated at between 6000-8000 tons of TNT which is 1/2 to 2/3'rds of the bomb's yield that was dropped on Hiroshima. The Tunguska comet/asteroid explosion in 1908 was the equivalent of a 15-40 megaton bomb. The Near Earth Asteroid Tracking observatory keeps turning up previously unknown near earth asteroids all the time so it's just a matter of time before NASA will have to deflect or destroy an incoming asteroid lest it destroy some part of us." We ran another story about this earlier this year.

Comments

NASA *can* hit asteroids...

[Dr. Zowie]

The initial problem with the Eros rendezvous wasn't a navigational issue. It was a problem with the spacecraft rocket motor not switching off! Deep Impact won't have such a long final burn -- just midcourse corrections, where there's plenty of time to fix any problems.

I work with scientific spacecraft, and I'm still always surprised at the precision with which we can determine distances and positions of distant objects. SOHO is a million miles from Earth, and its radial position is known to within a few centimeters.

Barring egregious mismanagement, it's not that hard to hit celestial bodies -- we have the right tools for the job!

NEATO

[FortKnox]

The Near Earth Asteroid Tracking observatory

Am I the only one that sees the abbreviation for the Near Earth Asteroid Tracking Observatory is NEATO?

I bet they did that on purpose, those crazy astronomers!

Interception smallest part of problem

[ColGraff]

At least when intercepting an asteroid or come, you can get an idea of the thing's orbit from Earth (although with a comet you have to allow for random outgassing). However, to destroy or move an asteroid or comet, you have to know mass and composition. This is the sort of thing that would have to be determined by a probe, with a high degree of detail. Knowing the composition of a tiny piece won't do - you have to know what most of the asteroid is made of with a high degree of certainty, and where all the different material deposits are located in order to find center of mass.
Right now, we don't have the ability to do that. This interception is, in reality, rather meaningless from an Earth-protection point of view, although it is cool. And of course, there's always the scientific benefit.