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Asteroid Evolution
Mar. 10th, 2007 11:37 pmI read an interesting report in the BBC about light causing asteroids to spin faster. I wonder if this might mean there is a lower stable limit for asteroids.
My thought experiment runs thus: The Yorp effect spins objects faster and faster with the upper limit being their structural integrity. A large mass object probably would not be imparted much spin as their mass to surface area ratio would be higher. If a 114 meter across asteroid is only spun up at about 1 millisecond a year then for a asteroid of double the diameter would probably be only spun about one quarter that value, all else being equal. The asteroid observed will probably spin apart in 15-40 million years. So at least double that for a much larger asteroid. Call one billion years essentially stable and my black of the envelope guesses would lead me to believe that anything under about 2.5 km would be unstable over the life of the solar system. With a very, very large error bar on my calculations since I'm doing them in my head without taking into account everything these scientists know.
Rather too bad that it doesn't do more about larger objects. If so the potential impactors of earth problem would be slowly taking care of itself. And now to bed as I am still very tired from the whole sickness thing I've just been getting over.
My thought experiment runs thus: The Yorp effect spins objects faster and faster with the upper limit being their structural integrity. A large mass object probably would not be imparted much spin as their mass to surface area ratio would be higher. If a 114 meter across asteroid is only spun up at about 1 millisecond a year then for a asteroid of double the diameter would probably be only spun about one quarter that value, all else being equal. The asteroid observed will probably spin apart in 15-40 million years. So at least double that for a much larger asteroid. Call one billion years essentially stable and my black of the envelope guesses would lead me to believe that anything under about 2.5 km would be unstable over the life of the solar system. With a very, very large error bar on my calculations since I'm doing them in my head without taking into account everything these scientists know.
Rather too bad that it doesn't do more about larger objects. If so the potential impactors of earth problem would be slowly taking care of itself. And now to bed as I am still very tired from the whole sickness thing I've just been getting over.