Washington, Dec 18: New data gathered by the Cassini-Huygens Mission has detected a hot spot on Enceladus, the tiny satellite of Saturn, which has raised intriguing possibilities of whether or not life exists on its surface.
The moon Enceladus is only 500 kilometers wide - roughly 300 miles wide, the distance between St. Louis and Chicago.
Data from Cassini has revealed a rock-rich body, 55 to 60 percent rock by mass, with a surface of nearly pure water ice.
The temperature at the poles is some -220 degrees Celsius (C), but the hot spot is at least 100 degrees warmer. This indicates that though Enceladus is colder than ice, there is a large amount of heat being generated at a hot spot on its south pole.
According to William B. McKinnon, Ph. D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, this hot spot has enough heat to eject plumes of ice and vapor above Enceladus.
This process makes a small part of the planet hot, relatively, for an icy satellite.
"You only have to get so hot to make ice active, " said McKinnon. "It doesn't have to get tremendously hot like it does on Io (one of Jupiter's moons). Ice volcanism requires an order of magnitude less energy for things to work out pretty well. The hot spots are -100 degrees C or possibly 'warmer'; the area around it is more than twice as cold. We still can't say how truly 'hot' the hot spots are. We'll probably learn this in March. "
"The plume particles are like smoke, ice smoke. If you were standing on Enceladus' surface, you wouldn't even be able to see the plumes, " said McKinnon.
The particles are just larger than the wavelength of light, about one-thousandths of a millimeter. Most icy bodies of this size are geologically inert, but this is a clear indication of geological activity.
"Cassini has found active venting of water vapor. This leads to scientifically intriguing speculations and questions, " said McKinnon.
One of these speculations is the possibility of life on the satellite, especially since it has water vapors.
"I don't think so. The strongest piece of evidence against that is measurements made from Earth of the plume don't show any sodium. If the source of the plumes were fresh water like on Earth, the plumes would contain enough detectable sodium, " said McKinnon. "Fresh water flows through rocks and on streambeds, and so it picks up bits of mineral chemistry. The emerging view is that there's not obvious evidence for a subterranean ocean in contact with rock, no boiling or venting, " he added.
Cassini, which has been passing through the plumes of Enceladus, makes its next pass in March of 2008. It will go deeper into the plume and take more pictures of the moon's features, the venting area in the infrared, impact craters, cracks and fissures, and make better measurements of gases and vapors. (ANI)
