Cassini's new view of land of lakes and seas

October 11, 2007
Cassini's new view of land of lakes and seas
Titan's north polar region

The best views of the hydrocarbon lakes and seas on Saturn's moon Titan taken by the Cassini spacecraft are being released today.

A new radar image comprised from seven Titan fly-bys over the last year and a half shows a north pole pitted with giant lakes and seas, at least one of them larger than Lake Superior in the USA, the largest freshwater lake on Earth. Approximately 60% of Titan's north polar region, above 60° north, has been mapped by Cassini's radar instrument. About 14% of the mapped region is covered by what scientists interpret as liquid hydrocarbon lakes.

"This is our version of mapping Alaska, the northern parts of Canada, Greenland, Scandinavia and Northern Russia," said Rosaly Lopes, Cassini radar scientist at the Jet Propulsion Laboratory, USA. "It is like mapping these regions of Earth for the first time."

Lakes and seas are very common at the high northern latitudes of Titan, which is in winter now. Scientists say as it rains methane and ethane there, these liquids are collected on the surface, filling the lakes and seas. Those lakes and seas then carve meandering rivers and channels on the moon's surface. Now Cassini is moving into unknown territory, down to the south pole of Titan.

"We want to see if there are more lakes present there. Titan is indeed the land of lakes and seas, but we want to know if this is true now for the south pole as well," said Lopes. "We know there is at least one large lake near the south pole, but it will be interesting to see if there's a big difference between the north and south polar regions."

It is summer at Titan's south pole but winter should roll over that region in 2017. A season on Titan lasts nearly 7.5 years, one quarter of a Saturn year, which is 29.5 years long. Monitoring seasonal change helps scientists understand the processes at work there.

Scientists are making progress in understanding how the lakes may have formed. On Earth, lakes fill low spots or are created when the local topography intersects a groundwater table. Lopes and her colleagues think that the depressions containing the lakes on Titan may have been formed by volcanism or by a type of erosion (called karstic) of the surface, leaving a depression where liquids can accumulate. This type of lake is common on Earth.

"The lakes we are observing on Titan appear to be in varying states of fullness, suggesting their involvement in a complex hydrologic system akin to Earth's water cycle. This makes Titan unique among the extra-terrestrial bodies in our solar system," said Alex Hayes, a graduate student who studies Cassini radar data at the California Institute of Technology in the USA.

"The lakes we have seen so far vary in size from the smallest observable, approximately 1 square km, to greater than 100 000 square km, which is slightly larger than the great lakes in midwestern USA," Hayes said. "Of the roughly 400 observed lakes, 70% of their area is taken up by large ‘seas’ greater than 26 000 square km."

Source: European Space Agency

Explore further: Extreme methane rainstorms appear to have a key role in shaping Titan's icy surface

Related Stories

Cassini's search for the building blocks of life on Titan

September 13, 2017

Lakes and seas of liquid methane, rain from hydrocarbon clouds, and evidence of poisonous hydrogen cyanide in the atmosphere of Titan were just some of the discoveries the Cassini probe made of Saturns's largest moon.

Saturn plunge nears for Cassini spacecraft

August 30, 2017

NASA's Cassini spacecraft is 18 days from its mission-ending dive into the atmosphere of Saturn. Its fateful plunge on Sept. 15 is a foregone conclusion—an April 22 gravitational kick from Saturn's moon Titan placed the ...

Recommended for you

NASA telescope studies quirky comet 45P

November 22, 2017

When comet 45P zipped past Earth early in 2017, researchers observing from NASA's Infrared Telescope Facility, or IRTF, in Hawai'i gave the long-time trekker a thorough astronomical checkup. The results help fill in crucial ...

Uncovering the origins of galaxies' halos

November 21, 2017

Using the Subaru Telescope atop Maunakea, researchers have identified 11 dwarf galaxies and two star-containing halos in the outer region of a large spiral galaxy 25 million light-years away from Earth. The findings, published ...

Cassini image mosaic: A farewell to Saturn

November 21, 2017

In a fitting farewell to the planet that had been its home for over 13 years, the Cassini spacecraft took one last, lingering look at Saturn and its splendid rings during the final leg of its journey and snapped a series ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.