Bad Astronomy

Putting the Spin on Saturn’s Hex

I get the odd (and I do mean odd) email every now and again from someone whose grasp of science is somewhat, um, tenuous. They tend to have unusual explanations for phenomena ranging from THEIR MIND-BLOWING THEORY THAT PROVES EINSTEIN WAS AN IDIOT to aliens visiting them and planting solutions for world peace in their brains.

Photo by NASA/JPL/Space Science Institute

A lot of these emails are motivated by weird observations that on the surface don’t make sense. A great example of this is the bizarre hexagonal cloud feature at Saturn’s north pole. Seen here using images taken from Cassini, the storm is definitely freaky: how do you get a hexagonal shape on a spinning round planet?

Via Boing Boing, I found this really cool video that shows that this is actually expected under some circumstances! Scientists used a slowly spinning cylinder of water and created a much faster “jet stream” by using a more rapidly spinning ring inside the cylinder. What they got is, well, Saturn’s hex:

[I’ll note that my pal Emily wrote about this a few months ago at The Planetary Society blog, too, but I somehow missed it.]

Pretty cool. It forms a hexagon! And you don’t need aliens, the electric Universe, plasma physics*, or anything like that. Just plain old fluid dynamics and a rotating plate.

I never would have thought that could happen. It goes to show you that our common sense fails us pretty miserably when we try to change from our relative stationary frame of reference to a spinning one, or vice-versa. After all, it’s not exactly intuitive that we’re standing on a vast spinning ball of mud flying through space, but there you go.

* Note: by mentioning plasma physics, I don’t mean to be lumping legitimate plasma physics in with the abuse of it by the Electric Universe folks. I was in fact referring to those people when I listed it. I hope no actual scientists took offense.

Related posts:

- A hex on Saturn
- A hex on Saturn (again)!
- Science wins at SMBC