Blogs / Bad Astronomy

… and one of them is expelled. Actually, one was expelled and the other was Expelled.

This has to be read to be believed. Normally I’d add that the manager movie producer obviously had good taste, but there’s no way I can make my usual sarcastic snark about PZ here, because the manager of the theater producer is obviously a total jerk. He’s within his rights, but that doesn’t make him any less of a tool.

A few updates: Here’s a (very NSFW language-ridden) first-hand account of what happened from someone who was right there. You may be amused to hear that the Kevin Miller, who wrote the movie, has a fallacious account of what happened on his blog; the spin is that PZ wasn’t invited, though the truth is you didn’t need an invitation to go. He also links to another account that is at very strict odds against PZ’s own account and that of the other first-hand witness. Oh, those wacky creationists! Is there nothing they can’t lie about?

Another update (March 22): PZ has posted clarifying (to me at least) that it was the producer of the movie who had him thrown out, not the theater manager. I wanted to make sure that this was corrected, because I certainly don’t want innocent people to be falsely accused of anything.

The new season of Doctor Who starts on April 5!

W00t!

Mild spoilers below:

The first episode is called "Partners in Crime", and Catherine Tate returns as Donna Noble, which anyone who reads this blog should know by now. Personally, I think her character had a lot of room in it for some great development between her and the Doctor. When he said he doesn’t need anyone, and she replies, "Yes you do, ’cause sometimes I think you need someone to stop you,"… well. The Doctor is a tortured man, and I’d like to see more of this. We got a glimpse of that in "Family of Blood" and the season 3 finale as well. I certainly hope they develop this idea more in Season 4, and given what spoilers I’ve heard… well, we’ll see.

A startling result from the Cassini mission has just been announced: Titan, Saturn’s giant moon, may have an ocean of water and ammonia under its surface.

The Cassini probe does more than return hauntingly beautiful images. It is equipped with a sort of radar that allows it to map the topographical features of Saturn’s moons. This allows scientists to make accurate studies of the moons’ surfaces, including that of Titan. This in turn gives scientists an excellent set of landmarks, allowing them to study physical characteristics of the moons, including their rotation period.

Titan’s period is well-studied, and Cassini has visited Titan many times. Astronomers used the known landmarks and rotation period of Titan to predict what they will see with each visit… and they found landmarks like lakes and mountains that were far afield of where they were expected, as much as 30 kilometers (19 miles). A solid body will rotate as such, making these features very predictable. If the landmarks weren’t where they should be, then it must mean that Titan isn’t a solid body.

The more detailed story is that the crust, the surface layer of the moon must be decoupled, separate, from the interior. The only way for that to be is for there to exist a liquid layer between the surface and the core. Titan is far too cold and is comprised of the wrong material to have a hot mantle like the Earth does. Instead, scientists think it has an ocean 100 km below its frozen surface. Given the composition of the surface and the known density of Titan, they suspect it is made of liquid water and ammonia. The crust floats over this chilly liquid, and as winds blow on the surface the crust drifts, causing the predictions of landmark locations to be off.

The surface of Titan is loaded with what we call simple organic molecules: ethane, methane, and more. It is shocking, to say the least, to consider what would happen when you mix liquid water and organic compounds. Could there be life swimming deep under the surface of that planet-sized moon?

At the moment — and for the foreseeable future — there is no way to know. The ocean, if it exists, has not yet been confirmed, so we don’t want to put the cart before the horse. A lot of hard work lies ahead for those who study this distant world — seasonal variations in the positions of Titan’s landmarks would indicate that it is indeed the atmosphere blowing over the surface that is changing the rotation of the crust itself, and that in turn would give much credence to the idea of an underground ocean.

If this does pan out, then we will have to add yet another object in our solar system to the short list of worlds where liquid water can and does exist. And given the near-certainty of liquid water below the surface of Enceladus, Saturn will be able to proudly claim at least two them.

Take a ride with robots over at, er, Riding with Robots for the 46th Carnival of Space! As always, there’s a smorgasbord of cosmic bloggy goodness there.

Holy Haleakala! Yesterday, a gamma-ray burst went off that was so bright that had you been looking at the right spot in the sky you could have seen it with just your own eyes!

It’s difficult to put this into the proper context. GRBs are monumental explosions, the exploding of a massive star where most of the energy of the catastrophe is channeled into twin beams of energy. These beams scream out from the explosion like cosmic blowtorches, and for thousands of light years anything they touch is destroyed. Happily for us, GRBs always appear hundreds of millions or billions of light years away.

Let me put this in perspective for you. Imagine a one megaton nuclear weapon detonating. That’s roughly 50 times the explosive yield of the bomb dropped on Nagasaki. Devastating.

The Sun, every second of every day of every year, gives off 100 billion times this much energy. That’s every second. A star is a terrifying object.

In the few seconds that a gamma-ray burst lasts, it packs a million million million times that much energy into its beams. In other words, for those few ticks of a clock the GRB is sending out more energy than the Sun will in its entire lifetime.

There is, quite simply, no way to exaggerate the devastation of a gamma-ray burst.

Yet for all that, they are optically faint due to their terrible distance. At billions of light years away, even the Universe’s second biggest bangs are difficult to see.

So that’s what makes GRB 080319B (the second GRB seen on 2008 March 19) so incredible: distance measurements put it at 7.5 billion light years away, yet it was visible to the unaided eye had you just happened to be looking up at the sky at that moment.

Whoa.

This is the single brightest GRB ever seen in optical light, so as you can imagine reports are pouring in from observatories all over the world right now. Anything this bright must be extraordinary, and you can bet that astronomers will be falling over themselves to observe this incredible event. We still don’t know enough about GRBS; just what mechanisms focus those beams? We know black holes are at their core, powering these events, but how do the gravity and magnetic fields come together to generate forces like this? How tightly focused are the beams? Do they open at a one degree angle? 5? 10? Why does every GRB behave somewhat differently, with some lasting for seconds and others for minutes?

And why was this one so frakkin’ bright? Was it a more energetic explosion itself, or were we, by coincidence, looking precisely down the center of the beam? If the beam of a GRB is pointed ever-so-slightly away from us, so that the edge nicks us, the GRB will look fainter. By staring down the throat of a GRB we’d see it as bright as it could possibly be. Maybe GRB080319B had us dead in its sights.

Watching the extremes of GRB behavior can help us constrain the more normal aspects of them… if you can even use the word "normal" when it comes to such titanic explosions on these scales. There is a fascination we humans have with such terrible events, an atavistic thrill even when our puny brains can’t comprehend the size and scale of them.

I wrote about GRBs extensively for my book Death from the Skies!, and spent a lot of time working through the math and thinking about the destruction they can wreak. If you want to know what my nightmares look like, then GRBs are a good place to start. I’m just glad there (most likely) aren’t any stars nearby that can do this. I like GRBs… when they’re far, far away.

BABlogee William Blakeslee recently sent me a link to a site that is still debating the veracity of the Moon landings. Read it if you can stomach it; the claims being made by the Hoax Believers are ones that even Joe Rogan would leave alone. One guy is claiming we couldn’t have made it through the radiation belts! I mean, c’mon. How many times does this stuff have to be debunked?

I guess it’s an infinite number of times, equal to the human capacity to be totally fooled by zero evidence. As I’ve been quoted so often as saying, eternal vigilance is the price of freedom.