Asteroid that broke up over Berlin was fastest-spinning one ever seen

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.

That doesn’t seem particularly fast of a spin and I’m surprised it’s the fastest one observed.

There is a moment in 2001: A Space Odyssey that I’ve always liked. It’s at about 1:13:15 or so, and is just a distant shot of the Discovery One. Suddenly two space rocks silently tumble past. I like the scene because it gives a sense of the scope and silence of outer space, but I suppose it would be incredibly rare to be so close to even one rock, let alone a pair. And they are tumbling at about the pace measured by the one in that article, so perhaps even rarer still.

I’m surprised to learn that one rotation every 2.6 seconds is the fastest we’ve ever seen. That actually seems kind of slow. I can think of lots of things that rotate faster than that, including me if I want to. Is this mainly because the solar system is old and energy has dissipated over time?

> space rocks larger than a kilometre can’t rotate more than once every 2.2 hours because they would break apart.

Curious, what is that number for a space rock the size of Earth?

REPENT - awakenberus

Spinning, huh? If you’re a Tim Powers fan who has read “Declare”, well, you know what THAT means. (And it’s Berlin, too!)

"UFO"