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ESA Plans Test of Asteroid Defense System
vinlud writes "It has been announced by Dutch television ESA has chosen the Don Quijote programme to investigate the possibilities of altering the collision course of asteroids heading for Earth. The program, selected among five other studies, contains two spacecraft: Hidalgo and Sancho. Hidalgo will impact an asteroid of approximately 500 m diameter at a relative speed of at least 10 km/s while Sancho will retreat to a safe distance to observe the impact. An animation of the mission sequence (6.49 Mb) can be downloaded from here."
This animation is like something out of high school. Look as the stuff JPL does.
The animation is so poor, and spends so much time on irrelevance (half is spent watching a crude stick drawing of the launch) that the point is lost.
Frankly, it makes the ESA look like its being run by a bunch of amateurs on a shoe-string budget. It does not inspire confidence.
And I say this knowing that the work they're doing is top notch. But this animation is so bad its spooky.
is this just a hip way to repackage missile defense testing so that nobody gets mad?
With the ability to correct the flight enroute, it shouldn't be too difficult at all. When Cassini went into orbit around Saturn, the navigation was so precise that they did not need to do a corrective burn.
Still, if for some gosh-awful reason you can't hit a 500 m target, this is the perfect time to find out!
Here's a bunch of folks that will probably have fun looking to see what effect the collision might have: The folks on the Minor Planet Mailing List are really into tracking the orbits of these rocks. I wouldn't be surprised if their data is the stuff that narrows the error bars on this experiment!
This sig seemed like a good idea at the time....
Assuming that the Hildalgo probe masses in at 25 kg (the same as Sancho - it might be less) and is moving at 10km/sec and assuming the asteroid has a density of 3g/cc (giving a mass of 4x10^10 kg, and if the probe is absorbed into the asteroid and no material is lost from the asteroid, then the change of velocity for the asteroid will be about 6x10^-9 km/sec.
For comparison, the asteroid probably has a velocity somewhere on the order of 5-10km/sec.
If the asteroid and probe hit head on with both having a velocity (relative to the sun) of 10km/sec, then you can double the change to 1.2x10^-8 km/sec
It's probably a good idea to check my work. Here's how I did the calculation:
Let m1 be the probe and m2 be the asteroid.
v(center of mass)=(m1*v1+m2*v2)/(m1+m2). v2=0 for this reference frame and m1+m2 essentially equals m2. Since we're in the reference frame of the asteroid being stationary, the combination of probe and asteroid will still have the same velocity for the center of mass.
I hope I didn't botch this estimate....
This sig seemed like a good idea at the time....
Not only does it accurately represent the potential effectiveness of this particular program, but also the necessity for an asteroid defense program in general. But I suspect the technology could be useful someday, likely for something other than the defense of the Earth from asteroids.
astronomy is a clasical and easy explanation, the problem I have with this one, is that 1) is too simple and 2) is an opinion from our own culture, 'we' have astronomy but what about the ones that lived 20Ky before?.
There's still no reason to believe that devastating impacts are more frequent than we did before.
No, no more frequent, but if our memories are right, they already happened (ie: there are strong indications of an abrupt end of the Bronce Age (3.5Ky), that expanded across northen africa to middle east and extensive fiires on south europe). Those are not very ancient events, the problem is that our memories are very short.
What's in a sig?
Here are some odds and probablities as compiled by the oddities who write The Edge for The Oregonian (Portland, OR newspaper). Short version: it is actually more likely that the Earth will be smacked by a large asteroid in your lifetime than you becoming a professional athelete.
And remember, before you try to beat the odds, make sure you can survive the odds beating you.