[ExI] Luciano Iess: Liquid ocean on Saturn's moon Titan

Tomasz Rola rtomek at ceti.pl
Thu Jul 26 18:49:12 UTC 2012


moon TitanCassini spacecraft image of Titan		

Cassini spacecraft observation of “tides” in the solid surface of 
Titan suggest that this large moon of the planet Saturn has an ocean below 


Scientists have long suspected that Saturn’s largest moon, called Titan, 
might have a liquid ocean beneath its surface. New analysis of data from 
NASA’s Cassini spacecraft now has lead to the “almost inescapable” 
conclusion that, indeed, Saturn’s moon Titan likely harbors a layer of 
liquid water under its ice shell. This finding appeared in the June 28, 
2012 issue of the journal Science. EarthSky spoke to planetary scientist 
Luciano Iess of Sapienza University in Rome, Italy, who led the discovery 
team. He said:

The main finding is that underneath the external icy crust of Titan, there 
is an underneath ocean. There is a liquid layer. The study was carried out 
by studying, essentially, the tides on Titan.

This artist's concept shows a possible scenario for the internal structure 
of Titan, as suggested by data from NASA's Cassini spacecraft. Scientists 
have been trying to determine what is under Titan's organic-rich 
atmosphere and icy crust. Image credit: A. Tavani

Unlike the tides familiar to beach-goers on Earth, the tides on Titan are 
up and down movements of the surface ice. Earth also undergoes measurable 
land tides, caused by our nearby moon. If Titan were made entirely of 
stiff rock and ice, the scientists say, the gravitational attraction of 
Saturn would cause “tides” on Titan’s solid surface about three feet 
(one meter) in height. Instead, according too the estimates of Iess and 
his team, Titan’s tides are as large as about 30 feet (10 meters) – 10 
times larger than anticipated. 

The height of these moving bulges, or tides, suggests Titan is not made 
entirely of solid rocky material. That is why, scientists believe, there 
must be liquid water beneath Titan’s surface. 

The height of the land tides on Titan let Iess’ team estimate the amount 
of water in Titan’s underground ocean. Iess said there could be more 
than 10 times all the water of Earth. Because Titan’s surface is mostly 
made of water ice, which is abundant in moons of the outer solar system, 
scientists infer Titan’s ocean is likely mostly liquid water. Otherwise, 
Iess said, little is known about the underground ocean on Titan.

On Earth, water means life. Does the presence of an underground ocean on 
Titan indicate there is life on this moon of Saturn? Dr. Iess said:

We have discovered water. We don’t have to expect that this water 
contains life. It may or may not. I’m personally rather skeptical, but 
this is a matter of judgment, which may not be too scientific after all. 

Saturn's largest moon, Titan, as seen by the Cassini spacecraft. When we 
gaze at the moon with the eye, we see only the upper layers of its dense 
atmosphere. But many mysteries lie beneath.

The Cassini spacecraft made it possible to measure the height of the tides 
of solid ice on Saturn’s moon Titan. Cassini has been orbiting Saturn, 
and winding among the ringed planet’s moons, since 2004.

Bottom line: Cassini spacecraft observation of land tides in the solid 
surface of Titan suggest that this large moon of the planet Saturn has an 
ocean of liquid water below its icy surface. Planetary scientist Luciano 
Iess of Sapienza University in Rome, Italy led the discovery team. The 
team made their announcement in late June 2012.

Cassini scientists: Mystery of Saturn’s jet streams solved

Tomasz Rola

** A C programmer asked whether computer had Buddha's nature.      **
** As the answer, master did "rm -rif" on the programmer's home    **
** directory. And then the C programmer became enlightened...      **
**                                                                 **
** Tomasz Rola          mailto:tomasz_rola at bigfoot.com             **

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