Yellowstone isn’t the only place in the Solar System to see some fantastic aqua explosions. The incredible active geysers and water volcanoes on the Saturnian moon Enceladus put Old Faithful to shame.
Enceladus is a small gray-white world coated in ice. Its surface is covered in vein-like pale blue lines called "tiger stripes". They mark the boundaries between enormous ice sheets that encase the planet and may hide a vast, deep ocean beneath.
Astronomers and astrobiologists, always on the lookout for promising signs of life, were caught by complete surprise. No one can explain how such a small celestial body (only 318 miles wide at its equator) can pump out so much water.
"Nobody has figured it out," says Andrew Dombard of Johns Hopkins University's Applied Physics Laboratory in Laurel, Md. "Enceladus has jumped to the top of astrobiologists' list for a mission."
Now NASA is sending Cassini back to the mysterious moon, to fly straight into a deep-space geyser close to the planet’s surface.
During a previous fly-over it was discovered that one geyser (sometimes jokingly referred to as Cold Faithful) pumps out about a ton of water every 8 seconds. But it’s not just water, it seems to be a mixture of life's building blocks — organic compounds such as methane, propane, acetylene and carbon dioxide, as well as nitrogen.
The rare occurrence of liquid water so near the surface raises new questions about the possibility of life in our Solar System—questions that NASA wants answers to.
Cassini imaging team leader Dr. Carolyn Porco said, "If we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms."
Cassini’s upcoming deep-space shower is not without risk, but NASA says the opportunity is too good to pass up. Officials are fairly confident that the sturdy probe can pull it off.
"Cassini was never designed to fly this close, but we've just got to get in that plume and look at that material and see what it is and where it's coming from," said James Green, director of NASA's Planetary Division in Washington.
Cassini's geyser adventure is set for March 2008, when it will swing within 19 miles (30 kilometers) of Enceladus’ surface. The tight trajectory will move Cassini directly into an icy geyser.
Alan Stern, associate administrator for NASA's Science Mission Directorate in Washington, said that even though this will be a challenge for Cassini, he is also confident that the probe can pull the mission off.
"It's very exciting because it's something Cassini wasn't designed to do but should be able to do safely," Stern said.
Stern said they would be cautious with the spacecraft's more delicate instruments. They will be pointed away from the icy spray before entering the plume, leaving the particle analyzers safe to sniff out the geysers composition.
Green said NASA's Jet Propulsion Laboratory is currently analyzing the geyser's risk to Cassini and will be soon be submitting a formal assessment.
"We want to be able to safely do science [with Cassini], but push the limit," Green said.
Just the kind of adventurous spirit we space lovers crave!
Posted by Rebecca Sato