Monday, March 2, 2009

Green Death Gas From Space

I will, I promise, quit talking about Comet Lulin very soon. You can't really see it anymore, as it begins its lonely multi-million year journey back to the Oort Cloud, so there's not much left to say. But it was such a pretty one, with all that green and those two tails and such, I have to post one more thing. This is a video stolen from the ever-reliable Bad Astronomy site, a time-lapse of rock and ice and gas pouring off the head of Comet Lulin. It looks like a smoking matchhead to me. Makes me want to light up a cigarette.

Eric recently asked me what made the comet green, and I looked it up to give him an answer (he called me Mr. Wizard, gently assuaging my ego, so I couldn't say no). It's cyanogen gas, a poison related to cyanide. So the "smoke" in the video coming off the comet actually contains a deadly gas. It's pretty common in comets. There have been scares in the past that going through a comet's tail would kill us all - notably in 1909 when Halley's Comet came around - because of the cyanogen.

Nobody died.


Eric Shonkwiler said...

That's really awesome--a beautiful video. I'd completely forgotten about the comet scares. But how did we know they contained poison gas back then? Or did we, and we just assumed the tails were poison? I recall in older times they were bad juujuu, and foretold plagues and such. Just leftover wive's tales, then?

Come to think of it, I still don't quite get how we know there's cyanogen--I mean, I do, but I don't quite get the mechanics of it. Like cameras or TVs, I just know they work.

Thanks, Mr. Wizard. :)

Noel said...

There's something strangely romantic and poetic about cyanogen being related to cyanide--something so beautiful could kill you if you got too close.
Like a puffer fish. Or...a really nice knife.

Irrelephant said...

More's the pity, eh?

Clowncar said...

Eric, you can look at the light from the comet and tell what chemicals it's made of by examining the spectra through a prism. They're been able to do that for a very long time. So that's how they know.

It really is a pretty video.

Noel, nice to see you again. There's another level of meaning to it too, as comets have water and organic chemicals inside. So while they're deadly, they may have brought the components needed for life to earth.

Irr, you cynical bastard. Reading about the cyanide gas remined me of a very bad Conan Doyle sci-fi book called "The Poison Belt" I read as a kid. Have you read it? I'm guessing yes. I think it was based on Earth passing through poison "ether" or something.