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Asteroids torn apart by Earth
douglips writes "BBC News has a story about near-Earth Asteroids being broken up by Earth's tidal forces. The binary asteroid systems are studied to learn the density of the bodies, which is just the sort of thing you need to know if you want to nudge one out of a collision course with Earth."
The rotation curve for an asteroid is often determined by measuring the change in brightness of an asteroid over time. Plotting the light detected versus time yields a somewhat sinusoidal curve, which is usually interpreted to be due to the rotation period of a non-spherical asteroid. If binary NEAs are common, then what some of these light curves may actually be showing is the orbital period of the binary system (if they are synchronous this will be the same thing as the rotation period of the smaller component). This could mean a new interpretation of what may be behind some of these light curves.
As a further comment, the existence of double impact craters is not necessarily suggestive of binary asteroid systems -- an asteroid is more likely to break apart when it actually enters the Earth's atmosphere than in more distant encounters, so it's probably not good to assume that the system had already broken up and become a binary during a previous encounter.
Shame on you! Those asteroids are a natural resource that should be protected for all ages. Just because we're raping the ecosystem and pillaging the natural resources of Mother Earth, or Gaeia, as I like to call her, does not give us the right to rape and pillage outer space.
We need to set up a commission to study and develop plans for the immediate eradication of all tidal forces, especially those killer, destructive ones!
To celebrate the occasion of my 1000th post, I will post no more forever on Slashdot. Goodbye.
Zoltrax: Ah, you worry too much Zeetlix. Even if they ever get the technology to see the astroids splitting apart, earthlings are much too stupid to realize why.
Zeetlix: Even if they're only earthlings, Commander, eventually they'll figure out something's odd about astroids splitting up ONLY when they come close to their planet.
Zoltrax: Nah, don't worry about it! Someone will just make up some bullshit rationalization for why it's happening, and everyone will believe it. I mean, hey, look what happened to Jesus of Planet Christ and his invasion. A couple millenia later, and they've turned the whole thing around!
Zeetlix: Of course, you're right, Commander. Forgive me. Unleash the astroids!