Striking new photos of water-vapor geysers erupting from Saturn's
moon Enceladus were beamed to Earth this week by NASA's Cassini spacecraft in
orbit around the ringed planet.
Cassini made its deepest dive yet into the plumes pouring
out from the moon's south pole on Nov. 2 during a planned flyby of
Enceladus. The spacecraft approached within about 62 miles (100 km) of the
moon's surface.
The powerful plumes, which contain water vapor, sodium and
organic chemicals such as carbon dioxide, look a bit like the Old Faithful
geyser in Yellowstone National Park. They have intrigued scientists because
they suggest that a store of liquid
water may be present beneath the moon's crust to give rise to the water
vapor in the plumes. And if there is liquid water, there might be the
possibility of some kind of alien life.
"If we can put the pieces together - a liquid ocean
under the surface, heat driving the geysers and the organic molecules that are
the building blocks of life - Enceladus might turn out to have the conditions
that led to the origin of life on an earlier version of Earth," Cassini
scientist Bonnie J. Buratti wrote on NASA's Jet Propulsion Laboratory blog.
The aim of the recent flyby - Cassini's seventh targeted
swoop toward Enceladus - was to measure the size, mass, charge, speed and
composition of the particles within the plume. The spacecraft made a quick
approach traveling at about 18,000 mph (nearly 29,000 kph). In addition to the
scientific data, the spacecraft returned new stunning snapshots showing the enigmatic
geysers glowing in reflected sunlight against the dark backdrop of space.
"Not too bad being in orbit around Saturn, is it ?! ;-)"
wrote Carolyn Porco, head of Cassini's imaging science team, via Twitter. Porco
called the images "spectacular."
The joint U.S.-European Cassini
spacecraft was launched in 1997 on a mission to orbit Saturn, and
discovered the geysers on Enceladus in 2005. The spacecraft completed its
primary mission in 2008 and is currently in the middle of an extended phase
that runs through 2010.
"This is the first time we've found activity on a moon
this small," Buratti wrote, explaining that Enceladus is only about the
width of Arizona, with a diameter of 310 miles (500 km).
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