3 ms·

Objects that have a reasonable chance of colliding do go in the same direction.

• pdonis 9y ago
  > Objects that have a reasonable chance of colliding do go in the same direction. No, even that's not the case. If it were, the delta v of anticipated collisions would be low enough that they wouldn't pose a serious problem. The Wikipedia article on the Kessler syndrome, linked to upthread, gives some useful references. One of them is an article on how a cupola window on the ISS was pitted by a microscopic piece of space debris. The pit is 7 mm across, about the size of what a small rock would put in a car windshield at highway speed. How fast would an object about 1000 times smaller (and therefore about a billion times less massive) have to be traveling to have the same impact energy? (Hint: it's about the same as LEO orbital speed--but that's orbital speed relative to the ground, not relative to objects on nearby orbits in the same direction.)