Monday, February 23, 2009
Europa and Titan both could hold some kind of life: we'll keep exploring despite the hard times
Even in these troubled times, thought about exploring nearby worlds, at least with more unmanned probes and robots (“Wall-E”) for life goes on, and in our solar system, the two best chances are Europa, a moon of Jupiter, and Titan, the star of Saturn’s system.
Remember that the film “2010” (based on Arthur C. Clarke’s sequel) turned a leprous Jupiter into something like a brown dwarf and Europa into a real planet, with a chance to evolve – with earthlings told to leave Europa alone. The evidence is strong that it has a substantial water ocean underneath an ice crust, and that tital forces from Jupiter, along with volcanic activity, could mix things up enough for life like our simplest bacteria to form.
Titan, on the other hand, has a bizarre “reverse greenhouse” effect with an atmosphere that blocks out distant sunlight, and a surface temperature not much warmer than -300 F. Huygens pictures show a surface that looks like a desert, but in fact it seems that most of the surface is an ice, covered with organic sooty compounds called thiolins (Carl Sagan’s term). There may actually be an ocean underneath the ice, and then a further ice layer. That could lead to some interesting tectonics or water volcanoes, and there are Lake Superior-sized seas on Titan composed of ethane, methane or mixtures after “thunderstorms”. There could be some chemical process that demonstrates “life as we don’t know it.”
All of this is summarized today in a story by Joel Achenbach, p A6, of the Monday Feb. 23 Washington Post, Science Page, link here.
There are pictures online of Titan and Europa (and Mars, Venus, the Moon, etc) taken by NASA missions and they appear to have a “free copyright license” – effectively public domain. Most of the commons warnings that I find refer to accidentally using pictures of people in them. But right now, there’s not much risk of finding “people” on Titan – unless they’re angels.
Picture: Titan "Courtesy NASA/JPL-Caltech.". NASA Photojounral source online is here.
"Titan" is the fictitious company on NBC's soap "Days of our Lives".