Postcards From Titan
Cassini successfully finished its flyby of Titan the other night, and now NASA’s busily slogging through all the pictures and data it sent back. It’s going to take them a while, I’m sure, and for now they’re just putting up the most remarkable ones on their website. They’re staying away from really explaining what it is we’re looking at, possibly because they’re still trying to figure it out themselves. Look at the close-up photo. Is it solid? Is it liquid? Both? Could this be an ocean with lots of little islands, or just different colored rocks? NASA might know, or they might not, but they haven’t said yet.
Of course, nobody ever said the scientific process was quick. I remember back when Galileo was doing its survey of Jupiter and its moons, and not many people were visiting NASA’s website hours after a flyby looking for quick news. Back then I was content to wait until Scientific American put together an article on one of the moons, after they’d had plenty of time to process what they had found. Now I’m impatient. Too much instant news out there on the internet, I guess.
Photographing Titan is hard because it’s the only moon in the Solar system with an atmosphere. And it’s a thick, hazy atmosphere, more like Venus than Earth. So if they take pictures in visible light, all they get is this orange soup staring back at them. Exciting for a few seconds, maybe, but everyone wants to see what’s underneath the soup. That’s why for this part of the mission they rely heavily on the infrared and ultraviolet cameras, as well as radar. Those wavelengths can cut through the soup of Titan’s atmosphere and see the surface, and the pictures they get back look like real pictures. It’s just not what you would see if you were actually standing there.
Anyway, whatever they discover now, we’ll hear about it over the next few weeks. And it will all be augmented in a couple of months when they chuck the Huygens probe at the moon and see whether it goes splash or crunch.