Yesterday the journal Nature published two items updating research on Saturn's venting moon, Enceladus. Readers may remember that about six months ago the Cassini spacecraft, on a flyby of the moon, detected plumes of water vapor and ice shooting into space from cracks in its surface. At the time, mission scientists speculated the geysers originated deep below the surface, possibly from a liquid aquifer or ocean. Because traces of organic compounds were also found in the plumes, some cautiously suggested that conditions below the surface may be suitable to harbor life.
The latest developments concern sodium chloride, or salt, a fundamental component of seawater on Earth. Cassini team members with the Jet Propulsion Laboratory (JPL) at the California Institue of Technology reported the spacecraft detected salt in grains of ice within Saturn's outermost ring. However, another group of researchers using ground-based instruments did not find sodium in the plumes jetting out from the moon. Mission scientists say the evidence points to a deep water subterranean ocean on Enceladus. Others aren't so sure, and suggest some other source or sources may be responsible. Keyword: may. The current data are insufficient.
JPL manages the Cassini mission for NASA and its mission partners, the European Space Agency and the Italian Space Agency. On Wednesday JPL posted a news release describing the salt discovery. Abstracts of the Letters published in Nature are available here.
An interesting back story to the discovery of salt in one of Saturn's rings is that Cassini was supposed to end its mission in July 2008. NASA extended the project two more years, ensuring seven more close encounters with Enceladus.
The next flybys will happen in November.
Next stop: tbd
Banner bus photo credit: Dorothy Delina Porter