Article Posted on : - Dec 18, 2009

The image shows the first flash of sunlight reflected off a lake on Saturn's moon Titan. Image credit: NASA/JPL

CALIFORNIA (BNS): A flash of sunlight reflected off a lake on Saturn’s largest moon Titan has reconfirmed scientists’ belief that Titan harbours liquid hydrogen in the form of large lakes.

The image, taken by NASA’s Cassini spacecraft on July 8, 2009, has indeed allowed the researchers look deep inside Titan – its thick, hazy atmosphere, surface lakes and ‘an otherworldliness’.

The sun’s reflection, also called ‘specular reflection’, has been found on Titan’s northern hemisphere which has more lakes than its southern hemisphere. The region, which was veiled in winter darkness, has started receiving direct sunlight with the advent of spring.

“This one image communicates so much about Titan – thick atmosphere, surface lakes and an otherworldliness. It's an unsettling combination of strangeness yet similarity to Earth. This picture is one of Cassini's iconic images,” said Bob Pappalardo, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California.

Scientists have believed since long that Titan's cold surface hosts seas or lakes of liquid hydrocarbons, making it the only other planetary body besides Earth believed to harbour liquid on its surface.

While previous data from Cassini have not indicated any vast seas, they have revealed large lakes near Titan's north and south poles.

The researchers, after processing the new image, correlated it to the southern shoreline of a sprawling lake called Kraken Mare on Titan.

The finding shows that the shoreline of Kraken Mare has been stable over the last three years and that Titan has an ongoing hydrological cycle that brings liquids to the surface, said Ralf Jaumann, a visual and infrared mapping spectrometer team member. Of course, in this case, the liquid in the hydrological cycle is methane rather than water, as it is on Earth.

“These results remind us how unique Titan is in the solar system. But they also show us that liquid has a universal power to shape geological surfaces in the same way, no matter what the liquid is,” Jaumann said.