NASA's Cassini finds plethora of plumes and hotspots at Enceladus

Washington, Feb 24 (ANI): Newly released images from last November's swoop over Saturn's icy moon Enceladus by NASA's Cassini spacecraft have revealed a forest of new jets spraying from prominent fractures crossing the south polar region and yield the most detailed temperature map to date of one fracture.

The new images from the imaging science subsystem and the composite infrared spectrometer teams also include the best 3-D image ever obtained of a "tiger stripe," a fissure that sprays icy particles, water vapor and organic compounds.

There are also views of regions not well-mapped previously on Enceladus, including a southern area with crudely circular tectonic patterns.

"Enceladus continues to astound," said Bob Pappalardo, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

"With each Cassini flyby, we learn more about its extreme activity and what makes this strange moon tick," he added.

For Cassini's visible-light cameras, the Nov. 21, 2009, flyby provided the last look at Enceladus's south polar surface before that region of the moon goes into 15 years of darkness, and includes the most detailed look yet at the jets.

Scientists planned to use this flyby to look for new or smaller jets not visible in previous images.

In one mosaic, scientists count more than 30 individual geysers, including more than 20 that had not been seen before.

A new map that combines heat data with visible-light images shows a 40-kilometer (25-mile) segment of the longest tiger stripe, known as Baghdad Sulcus.

The map illustrates the correlation, at the highest resolution yet seen, between the geologically youthful surface fractures and the anomalously warm temperatures that have been recorded in the South Polar Region.

The broad swaths of heat previously detected by the infrared spectrometer appear to be confined to a narrow, intense region no more than a kilometer (half a mile) wide along the fracture.

In these measurements, peak temperatures along Baghdad Sulcus exceed 180 Kelvin (minus 135 degrees Fahrenheit), and may be higher than 200 Kelvin (minus 100 degrees Fahrenheit).

These warm temperatures probably result from heating of the fracture flanks by the warm, upwelling water vapor that propels the ice-particle jets seen by Cassini's cameras.

Cassini scientists will be testing this idea by investigating how well the hot spots correspond with the jet sources.

According to John Spencer, a composite infrared spectrometer team member, "The huge amount of heat pouring out of the tiger stripe fractures may be enough to melt the ice underground. Results like this make Enceladus one of the most exciting places we've found in the solar system." (ANI)