Astronomers in Berlin have spotted a gigantic sea of liquid on
Saturn's moon Titan. With an area of as many as 400,000 square
kilometers (154,400 square miles), the "Kraken Mare" is larger than the
largest sea on earth, the Caspian Sea.
While data sent back to earth by the Cassini spacecraft since 2004
has suggested fluids are present on Titan, latest infrared spectrometer
images of sunlight reflecting off an area of the moon's northern pole
indicates the presence of liquid methane or other hydrocarbons.
The images were made in July during Cassini's 59th orbit around Titan
from a distance of 200,000 kilometers (124,274 miles).
Smooth surface
Professor Ralf Jaumann of the German Aerospace Center said the
evidence of fluids is conclusive.
"We have been searching for this for a long time, and our idea was it
would be possible to prove the presence of fluids if we could capture
the reflection of the sun. The sun only reflects off liquids, and we saw
it do so."
Ice surfaces would be rough and non-reflective because of erosion and
sediments of atmospheric particles, he said.
Titan is the largest of Saturn's moons. It is cloaked in a thick
atmosphere which obscures visibility of its surface, and the scientists
studied images based on infrared wavelengths which penetrate the
atmosphere. A smaller sea of liquid ethane was discovered in 2008 on
Titan's southern pole.
Bildunterschrift: Cassini has been in
Saturn's orbit since 2004
Spacecraft outlives mission
German Aerospace Center researcher Ulrich Köhler said radar images
from 2006 confirmed the coastline of Kraken Mare, but it wasn't then
possible to prove the presence of liquids.
"Until recently it has not been completely clear if the individual
traces of fluids on this moon were current or left over from the distant
past," he said. "And now this seems to acknowledge that there currently
really are liquids on a planetary body other than the Earth. It must be
a very smooth surface, so it can really only be a liquid."
The Cassini spacecraft was launched in 1997 and completed the
four-year mission it was designed for in 2008, but is still functioning
well. The Kraken Mare was named after a sea monster in Norse mythology.
Bildunterschrift: Großansicht des Bildes
mit der Bildunterschrift: Ice
and liquid methane can be seen on the surface of TitanResearchers
from the German Aerospace Center will present their findings Friday at
the yearly conference of the American Geophysical Union in San
Francisco.
Author: Gerhard Schneibel
Editor: Nigel Tandy
