Yup. Planetary astronomer Mike Brown has just announced an amazing discovery: he and his team have found fog at Titan’s south pole!
Why is this so cool? Because it indicates there is a lot of liquid methane on Titan’s surface, something that wasn’t known for sure until now. We’ve been seeing lakes of something on Saturn’s giant moon for quite some time now, but it wasn’t clear what it was. Read Mike’s post for the details, but basically the two main suspects were ethane and methane. Ethane can rain out of the atmosphere of Titan and form lakes, but it just sits there and is essentially inert after that.
Methane, on the other hand, is more volatile, and can act on Titan the way water does on Earth: after condensing and falling out of the atmosphere as rain and form lakes, it can evaporate away… and that makes it far more interesting. Now that Mike’s team has seen fog on Titan – and methane is the most likely cause of it – then that means the evaporation has been detected for the first time.
On Earth, water is necessary for life and can exist in many forms (ice, liquid, gas). I’m not saying there’s life on Titan, nor is Mike. But it does mean that there is another large body in the solar system that has a chemical compound that goes through the same phases as water does here.
That makes Titan even more dynamic than we previously thought. It has a thick atmosphere, decent gravity, and a substance that acts like water. What else will we find as we observe this mammoth moon even more?
P.S. Mike’s journal paper is online. Now I have some fun reading to do.