Searching for ET

Fog on Saturn’s moon Titan strengthens claims that it may hold answers to how life began on earth.

As far back as 1695 the mathematician and astronomer Christiaan Huygens wrote in his book on extraterrestrial life, Cosmotheoros, ‘A Man that is of Copernicus’s Opinion, that this Earth of ours is a Planet, carry’d round and enlighten’d by the Sun, like the rest of them, cannot but sometimes have a fancy, that it’s not improbable that the rest of the Planets have their Dress and Furniture, nay and their Inhabitants too as well as this Earth of ours.’

Leave alone finding life elsewhere, the origins of life on earth continue to remain somewhat of a mystery. Ever since the orbiter Cassini started circling Saturn in 2004, evidence has continued to mount that the moon Hugyens spotted in 1655 may hold some of the answers. The first images from Cassini show a sphere glowing orange, its surface obscured by a ‘thick photochemical smog, rich in organic material’.

Now scientists using observations from instruments on board Cassini have detected fog on the south pole of Titan during late summer. According to a recent paper posted online at arXiv.org scientists have concluded that, ‘While terrestrial fog can form from a variety of causes, most of these processes are inoperable on Titan. Fog on Titan can only be caused by evaporation of liquid methane; the detection of fog provides the first direct link between surface and atmospheric methane. Based on the detections …liquid methane appears widespread at the south pole of Titan in late southern summer, and the hydrological cycle on Titan is current active.’

Experiments dating back to the 1950s involved taking a mixture resembling the earth’s atmosphere at the time life began and passing energy through it. The experiments yielded complex molecules. Similar complex molecules on Titan would verify the hypothesis of how life originated on earth. The presence of a hydrological cycle strengthens the case for its resemblance with early earth. The fog on Titan, it seems, may clear the air on life on earth.

About The Author

Hartosh Singh Bal