Tuesday, July 3, 2012

Liquid Ocean found on Saturn's Moon


Cassini in the JPL assembly room
Titan
Already Earth-like with a thick atmosphere and a rich stew of organic chemicals, Titan, Saturn’s large Moon also has a liquid ocean beneath its crust, as per the latest findings of NASA’s Cassini spacecraft show.
Gravity maps that have been meticulously pieced together from data collected over five years discovered Titan's shape changes by about 10 meters due to Saturn's gravitational pulls, a squishiness that is best explained by a liquid body of water relatively close to the surface.Scientists are not sure if the concealed ocean is nurturing lakes spotted on the Titan’s surface. Any ocean, however, would have been made up of water, which is rather more heavier that methane or ethane.
The confirmation of a ocean in Titan may not be completely true, however. The moon's rocky core could be filled with warm ice or it may be dehydrating..But the most likely explanation, said Luciano Iess, with Rome's Sapienza University and colleagues, is that Titan has a liquid ocean between 50 and 100 kilometers (31 to 62 miles) beneath the surface.One of the biggest questions about Titan's appropriateness for life is if the ocean touches rock, a source of minerals and a pathway for heat. Unlike Europa's ocean, which is believed to sit on a rock floor, Titan's water may be crammed between layers of ice, leaving it without contact to minerals and temperature deviations to bring new hopes for life beyond Earth.As Cassini flew around the moon for 6 times between 2006 and 2011, the scientists were able to measure Titan’s gravity. The measurements were made by tracing minute changes in the pitch of radio signals traveling between the spacecraft and Earth during the flybys.They found that the moon gets squeezed as Titan circles Saturn every 16 days.  The same occurs on Earth by the gravitational pull of the moon. The most visible effects here are the ocean tides, but the moon also distorts Earth's crust by 50 centimeters (about 20 inches.).Saturn's pull on Titan causes a 10-meter change. It won’t be as soggy as it is if it had been a solid.. The best fit for the data is that Titan contains a liquid layer of water a couple of hundred kilometers thick buried beneath 100 kilometers of surface ice.Scientist hope to polish the gravity maps with additional data from Cassini and additional computer modeling. Cassini’s next pass by Titan is on July 22nd. 

(Source- Discovery News)

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