3 ms·
There are two main mechanisms that cause asteroids to spin. The first is as a result of collisions, which is fairly intuitive. But even in the absence of any co
by antognini 2y ago
There are two main mechanisms that cause asteroids to spin. The first is as a result of collisions, which is fairly intuitive. But even in the absence of any collisions asteroids can acquire spin due to the YORP Effect (named after Yarkovsky, O'Keefe, Radzievskii, and Paddock). The idea is that if the surface is anisotropic (which is true of asteroids), then as the asteroid radiates heat, the photon pressure will be anisotropic and will start to impart a torque onto the body.
- jjtheblunt 2y agohttps://en.wikipedia.org/wiki/Radiometer https://en.wikipedia.org/wiki/Radiometer That's a toy i had as a kid, essentially!
- hoerensagen 2y agoThase are great. here is a brilliant technology connections video about it. https://youtu.be/t-JN2U4jHgk?feature=shared https://youtu.be/t-JN2U4jHgk?feature=shared
- z2h-a6n 2y agoNot to nitpick (I only stumbled upon this recently myself), but the mechanism driving a Crookes radiometer (which I presume is the type you're talking about) is not photon pressure, but interactions with the low pressure gas in the bulb [1]. [1]: https://en.wikipedia.org/wiki/Crookes_radiometer#Explanations_for_the_force_on_the_vanes https://en.wikipedia.org/wiki/Crookes_radiometer#Explanation...
- jjtheblunt 2y agoYes(!): the explanation on the little paper that came with it explained such.
- guenthert 2y agoI would expect that there is at least one more mechanism: out-gassing.
- antognini 2y agoTrue. Sublimation has more of an effect on icy asteroids than rocky asteroids.