NASA Buzzing about Life on Titan
The space agency is expected to announce that Saturn’s moon Titan has the conditions necessary for life as we know it.
NASA has called a press conference for Thursday, Dec. 2 at 2 p.m. ET, saying that it will “discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life.”
Artist’s conception of a lake on Titan – not water, but ethane
Have they actually discovered life? No, says one scientist who’s seen the paper that will be published at the same time. More likely would be that they’ve discovered evidence of bacteria using arsenic for photosynthesis. That sounds a bit arcane, but Titan has always been a magnet for astrobiologists looking for the possibility of extra-terrestrial life.
In many respects Saturn’s largest moon, Titan, is one of the most Earth-like worlds we have found to date. With its thick atmosphere and organic-rich chemistry, Titan resembles a frozen version of Earth, several billion years ago, before life began pumping oxygen into our atmosphere.
Titan is of great interest to scientists because it has a substantial, active atmosphere and complex, Earth-like processes that shape its surface. The moon is enveloped by an orange haze of naturally produced photochemical smog that frustratingly obscured its surface prior to the arrival of the Cassini-Huygens mission that dropped a probe onto the surface of Titan in 2005.
After parachuting through Titan’s murky skies, Huygens took measurements of atmospheric composition and wind speeds during its decent, along with an incredible series of images showing telltale patterns of erosion by flowing liquid. The probe came to rest on what appeared to be a floodplain, surrounded by rounded cobbles of water ice. (Photo right)
Cassini has revealed that Titan’s surface is shaped by rivers and lakes of liquid ethane and methane (the main component of natural gas), which form clouds and occasionally rains from the sky as water does on Earth. Winds sculpt vast regions of dark, hydrocarbon-rich dunes that girdle the moon’s equator and low latitudes. Volcanism may occur as well, but with liquid water as the lava.