Radio wave on Saturn's moon hints at hidden ocean
Last Updated: Monday, June 4, 2007 | 1:01 PM ET
CBC News
A mysterious radio wave detected on Saturn's largest moon may point to the location of an ocean hidden beneath its surface, the European Space Agency announced.
The discovery comes from evidence collected when the Cassini-Huygens spaceprobe made a descent over two years ago onto Titan, the only moon in the solar system known to have an atmosphere.
A composite view of Titan built thanks to Cassini images taken on October 9 and October 25, 2006.
(NASA/JPL/University of Arizona)
On Earth, radio waves occur naturally during lightning strikes, which cause electrons in the atmosphere to oscillate and release the waves. These radio waves bounce back and forth between the Earth's surface and its ionosphere, the high-up region of the atmosphere filled with electrically-charged particles.
But the discovery of radio waves on Titan, if verified, would be noteworthy for two reasons. For one, data collected from the space probe suggest little or no evidence of lightning to trigger naturally occurring radio waves, meaning another process must be at work.
The results would also be unusual because Titan's dusty surface makes a poor reflector of radio waves, which suggests the waves are bouncing off something that lies underneath the surface, according to Fernando Simões, a member of the team that runs the Huygens's sensor that made the discovery.
"The wave could have been reflected by the liquid-ice boundary of a subsurface ocean of water and ammonia predicted by theoretical models," Simões told the ESA.
"Titan is proving to be an intriguing environment," he said.
The next step for the researchers is to determine if the signal detected was the result of an error in the probe.
Titan is the first planet or moon from the outer solar system to successfully have a probe from Earth land on its surface. The discovery of the radio wave is one of several to be unveiled in an upcoming issue of Planetary and Space Science dedicated to the results of the probe.
Titan is the subject of much study within the scientific community, as it is thought to resemble what Earth might have looked like billions of years ago.
