Mystery Sand on Saturn Moon
Michael Schirber
ScienceNOW Daily News
_________________
Sand dunes are not unique to planet Earth: Astronomers have observed them on Mars and Venus. Now Titan, the largest moon of Saturn, may be included in this list, as new radar images of its surface reveal 100-kilometer-long dark stripes that resemble the rows of tall dunes seen in southwest Africa and Saudi Arabia. But what exactly makes up Titan sand, no one is entirely sure.
Sand dunes can reveal a lot about a region's climate and geology, as they require both erosion to break rocks into sand and wind to blow the sand into piles. Not too long ago, planetary scientists thought Titan lacked both of these ingredients. But as the European probe Huygens descended onto Titan's surface in January 2005 (ScienceNOW, 21 January 2005), its instruments detected winds that appear to be generated not by sunlight as here on Earth but by the strong gravitational pull from nearby Saturn. Huygens' cameras also caught glimpses of channels carved into the ice surface presumably by liquid methane, just as rock is eroded by water on Earth.
The potential for dunes on Titan was confirmed by more recent flybys by NASA's Cassini spacecraft.
May 04, 2006
Michael Schirber
ScienceNOW Daily News
_________________
Sand dunes are not unique to planet Earth: Astronomers have observed them on Mars and Venus. Now Titan, the largest moon of Saturn, may be included in this list, as new radar images of its surface reveal 100-kilometer-long dark stripes that resemble the rows of tall dunes seen in southwest Africa and Saudi Arabia. But what exactly makes up Titan sand, no one is entirely sure.
Sand dunes can reveal a lot about a region's climate and geology, as they require both erosion to break rocks into sand and wind to blow the sand into piles. Not too long ago, planetary scientists thought Titan lacked both of these ingredients. But as the European probe Huygens descended onto Titan's surface in January 2005 (ScienceNOW, 21 January 2005), its instruments detected winds that appear to be generated not by sunlight as here on Earth but by the strong gravitational pull from nearby Saturn. Huygens' cameras also caught glimpses of channels carved into the ice surface presumably by liquid methane, just as rock is eroded by water on Earth.
The potential for dunes on Titan was confirmed by more recent flybys by NASA's Cassini spacecraft.
May 04, 2006
