by Rich Bowden - Mar 12 2008, 02:37
Photo: Jets on Enceladus. Credit: NASA/JPL/Space Science Institute
Continuing its dramatic encounters with Saturn's moons, the space craft Cassini has been directed to make a "daring flyby" past Enceladus on Wed., March 12.
The craft will fly as close as 50 km to the the extraordinary moon, and should be able to view the moon's huge geysers which feature from fractures in the moon's south pole. NASA experts have said the craft should be able to sample water, ice and dust contained in the massive geysers.
"This daring flyby requires exquisite technical finesse, but it has the potential to revolutionise our knowledge of the geysers of Enceladus," said Alan Stern, associate administrator of NASA's Science Mission Directorate, Washington, "The Cassini mission team is eager to see the scientific results, and so am I."
The space agency's scientific team in control of the Cassini-Huygens mission have concluded that flying the craft so close to the geysers will not cause it damage as the particles in the eruptions are very small.
Analysers on board the craft will "sniff and taste" the collected particles and information concerning density, size and the composition of the materials will be gathered.
Artist's impression of surface of Enceladus. Credit: NASA
"There are two types of particles coming from Enceladus, one pure water-ice, the other water-ice mixed with other stuff," said Sascha Kempf, deputy principal investigator for Cassini's Cosmic Dust Analyser at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany.
"We think the clean water-ice particles are being bounced off the surface and the dirty water-ice particles are coming from inside the moon. This flyby will show us whether this concept is right or wrong," Kempf said.
Enceladus, taken from Voyager 2, August 26, 1981
However, to the disappointment of many, though Cassini will be only 50 km from Enceladus, it will not be able to take close-up images as its cameras will need to be pointed to outer space to maximise the craft's Ion and Neutral Mass Spectrometer (INMS) and its Cosmic Dust Analyser (CDA). However it will take shots of the amazing moon as it approaches and leaves.
Wednesday's flyby is the first of four such close encounters planned by the Cassini team this year.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.