NASA Outlines Asteroid Deflection Program

An anonymous reader submitted a link to an International Herald Tribune story about NASA's answer to the movie 'Armageddon'. Specifically, they've outlined a plan to deflect a planet-killer asteroid. "In 1998, Congress gave NASA's Spaceguard Survey program a mandate of 'discovering, tracking, cataloging and characterizing' 90 percent of the near-Earth objects larger than one kilometer (3,200 feet) wide by 2008. An object that size would probably destroy civilization. The consensus at the conference was that the initial survey is doing fairly well although it will probably not quite meet the 2008 goal." With this tracking system in place, scientists are hopeful an intervention could be staged before any grim choices have to be made. Assuming they have the money and manpower needed for the effort, NASA has actually outlined a pair of procedures that dove-tail with each other: "First we would deflect the asteroid with kinetic impact from a missile (that is, running into it); then we would use the slight pull of a 'gravity tractor' -- a satellite that would hover near the asteroid -- to fine-tune its new trajectory to our liking. (In the case of an extremely large object, probably one in 100, the missile might have to contain a nuclear warhead.) To be effective, however, such missions would have to be launched 15 or even 30 years before a calculated impact."

Comments

Make things worse?

[CommunistHamster]

Can we have an accurate estimate of the probability of a specific impact 30 years in the future? What if we change the course of an asteroid such that it has a new, better chance of hitting us the year after?

Off Topic

[Anonymous Coward]

This post comes up every once in a while. I always find it really amusing. Slashdot is essentially a trade magazine; it targets and draws IT professionals, usually a very high-paid group of people and not a group likely to live in their parent's basements. Then there is somebody who takes the time to sit around late Friday night/Saturday morning, and hit the refresh button over and over until he can get the first post (ie, somebody without a job, a girlfriend, or probably many friends) and uses it to accuse a community of well paid professionals of living in their parents basements.

Asteroid Radar System?

[vbwyrde]

I've always wondered if we could create a device that does the following:
1. Go into a position above the plane on which the planets rotate around the sun so it looks "down" on the solar system.
2. flash a bright light of a specified color every day at a certain time.
3. read back the ping signature of the solar system's objects with a light sensitive camera.
4. plug the changes into a computer.
5. calculate trajectories of all objects.
6. determine exactly which ones are on a bee-line for earth.
7. continue to monitor for any surprises.
8. focus on those objects that show they will come close to earth for deflection.

Is this possible to do? Or am I missing a fundamental something-or-other? Thanks.

How would nuclear weapons work in outer space?

[mosel-saar-ruwer]

In the case of an extremely large object, probably one in 100, the missile might have to contain a nuclear warhead.

On earth, a nuclear weapon causes damage via its atmospheric shock wave - it's the motion of the air that causes buildings to fall down [or implode, or whatever].

Do we even know how a hunk of rock would react to the introduction of a bunch of alpha particles/gamma rays/x-rays/infrared radiation/etc? How would the the crystalline structure of the rock be affected? What models do we have that indicate the rock would shatter from an internal heat differential, rather than merely glowing very bright red for a while [assuming the rock even chose to absorb the heat energy in the first place, rather than just deflecting it off into the void of outer space]?

By contrast, underground detonations of nuclear devices are very benign events, and release vastly less energy than a small earthquake or a small volcanic event.

It's only the gaseous shock wave of an atmospheric detonation that causes damage to humans & their metropolitan areas - in the vacuum of outer space, with no atmosphere [i.e. with no gas, hence no gaseous shock wave], a nuclear detonation might not be that big of a deal.

Re:How would nuclear weapons work in outer space?

[Anonymous Coward]

I don't think a nuclear weapon would prove effective if detonated near the object, however if the warhead penetrated the object (like bunkerbuster bombs do) and detonated the intense heat would vaporize the matter immediately surrounding it essentially turning it into atmosphere. This newly created super heated atmosphere would then escape though the hole that the nuke created essentially making short blast high intensity thruster. This improvised thruster would then hopefully push the asteroid out of the way enough to avoid impact with the earth.

Robert Pope

Re:How would nuclear weapons work in outer space?

[flyingsquid]

On earth, a nuclear weapon causes damage via its atmospheric shock wave - it's the motion of the air that causes buildings to fall down [or implode, or whatever].

Much of the damage caused by nuclear weapons, particularly hydrogen bombs, is actually from the intense heat released; the thermal energy is capable of causing severe burns miles from the point of explosion even after the air has absorbed most of the radiation (which is why, believe it or not, "duck and cover" isn't such bad advice). My suspicion is that you would want to detonate the bomb some distance above the asteroid; the heat would cause the surface of the asteroid to vaporize, and the gas jetted from the surface would shove the asteroid off course.

Re:Bringing Them *Closer*

[Hotawa Hawk-eye]

Before we start nudging asteroids into orbit around Earth, we should practice putting them in orbit around Mars. If we mess up and the asteroid impacts Mars, the energy released by impact will thaw any ice that may be trapped below the surface, thus helping a little bit with terraforming the planet, rather than slamming into Earth.