[ExI] Luciano Iess: Liquid ocean on Saturn's moon Titan
rtomek at ceti.pl
Thu Jul 26 18:49:12 UTC 2012
moon TitanCassini spacecraft image of Titan
Cassini spacecraft observation of âtidesâ in the solid surface of
Titan suggest that this large moon of the planet Saturn has an ocean below
Scientists have long suspected that Saturnâs largest moon, called Titan,
might have a liquid ocean beneath its surface. New analysis of data from
NASAâs Cassini spacecraft now has lead to the âalmost inescapableâ
conclusion that, indeed, Saturnâs 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 âtidesâ on Titanâs solid surface about three feet
(one meter) in height. Instead, according too the estimates of Iess and
his team, Titanâs tides are as large as about 30 feet (10 meters) â 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 Titanâs surface.
The height of the land tides on Titan let Iessâ team estimate the amount
of water in Titanâs underground ocean. Iess said there could be more
than 10 times all the water of Earth. Because Titanâs surface is mostly
made of water ice, which is abundant in moons of the outer solar system,
scientists infer Titanâs 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 donât have to expect that this water
contains life. It may or may not. Iâm 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 Saturnâs moon Titan. Cassini has been orbiting Saturn,
and winding among the ringed planetâs 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 Saturnâs jet streams solved
** 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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