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How To Deflect an Asteroid With Today's Technology
Matt_dk writes "Apollo 9 astronaut Rusty Schweickart is among an international group of people championing the need for the human race to prepare for what will certainly happen one day: an asteroid threat to Earth. Schweickart said the technology is available today to send a mission to an asteroid in an attempt to move it, or change its orbit so that an asteroid that threatens to hit Earth will pass by harmlessly. But what would such a mission entail?"
Oddly, we are doing detection totally wrong. We have several scopes out there looking for asteroids. But they will be picking up monster ones. The ones that are far more likely to hit us will not be picked up as easily. So what is needed? A cheap cheap telescope that can be roof mounted, and uses POE to provide data/power. In doing that, it will encourage a number of geeks around the world to install these. Then the scope relays data back to a central server where pics are compared. In particular, if one gets a flash, not a big deal. OTH, if several spread around the world get a flash in the same area (basically sunlight glancing off an asteroid as it slowly turns), then it says that the area should be looked at. This approach will enable us to know WHERE to look for small to medium asteroids.
I prefer the "u" in honour as it seems to be missing these days.
The "impact" method stands the chance of splitting the asteroid into man little pieces, and since that process of splitting absorbs energy less of it is available to deflect the body from its current course. To have enough mass going at a high enough velocity to contain enough energy to nudge it into a different trajectory you need heavy lift rockets with very fast final stage projectiles. The more velocity the more energy, but the more of that energy that will create debris that potentially causes even more problems. The best solution would be a very heavy object moving slowly, but the would be impossible to lift and deploy. Using nukes would allow a smaller projectile, but would very likely cause radioactive debris to renter earth's atmosphere. Not good. Its better to land on it and push it into the sun's gravity well.
The 'Gravity tractor' method requires just as much energy as pushing the asteroid, but you need LOTS of mass to make it work. Again you need heavy lift equipment to make this work, and I seriously doubt you can lift enough mass into space, and move it to where it needs to be, in time to effect the trajectory by much. You are still better off using that same fuel to get there quickly and push it lightly for a while into a new trajectory.
A vehicle placed at Venus's orbit, though, would be able to see those potentially dangerous asteroids quite well.
We don't only find the monster ones.
We commonly track asteroids under 500 feet wide; much smaller than a planet-killer.
It will be comparatively easy to detect a planet-killer sized asteroid and determine its trajectory in plenty of time to launch a deterrent mission.
A surprise impact by anything with major destructive capability is vanishingly unlikely at this point. Improvements in detection shouldn't be prioritized, but should be allowed to continue at a normal pace.
Deciding how to minimize the destruction should be the focus, and we don't really know how to do it with a high degree of confidence, yet. So deflection technology should be prioritized.
I would buy one of these in a heartbeat, and SETI already has the software and server resources to start to handle this. The expensive part though, will be the mechanisms for positioning, and reliably tracking in the night sky. Good tracking isn't cheap, as even the slightest vibrations will obfuscate really small objects. Add to that vibrations inherent on the roof of a home, Doors, washing machines, children playing, loud cars, wind etc. You would need a small solid tower separate from the home, as well as a lightning rod etc.
- Dan.
~ People that think they are better than anyone else for any reason are the cause of all the strife in the world.
So please, stop doomsaying, the experts say they are ready to nuke the sucker if that's what needs to be done.
MIT were saying that back in the 60s, so it's not really news.
But there's the slight problem of being able to _get_ a nuke to the asteroid in the first place; the MIT study used an Apollo CSM on top of a Saturn V with a 100MT nuke on board, and there's not much hope of being able to fix up one of the remaining Saturn Vs to fly at short notice and nuke an incoming asteroid today (they also planned to launch 5-6 of them to allow for failures and near misses).
The best choice is almost certainly to aim for the Pacific and evacuate all the coastal areas. The devastation from a mega-tsunami is far preferable (and more temporary) than the long-term climate disruption of a land collision. The amount of dust ejected into the air could easily trigger a "nuclear winter" kind of disaster.