Cassini Tastes Organic Material at Enceladus
On March 12, 2008, Cassini dived through Enceladus geyser-like jets. The jets themselves harmlessly peppered Cassini, exerting measurable torque on the spacecraft, and providing an indirect measure of the plume density.
As Cassini bravely dived through the plume at 15 km/s, the spacecraft’s Ion and Neutral Mass Spectrometer tasted organic materials, volatile gases, water vapour, carbon dioxide and carbon monoxide, some 20 times denser than expected.
“A completely unexpected surprise is that the chemistry of Enceladus, what’s coming out from inside, resembles that of a comet,” said Hunter Waite, principal investigator for the Cassini Ion and Neutral Mass Spectrometer. “To have primordial material coming out from inside a Saturn moon raises many questions on the formation of the Saturn system.”
Heat radiating from the entire length of 150 km-long fractures (the tiger stripes) is seen in this best-yet heat map of the active south polar region of Saturn’s ice moon Enceladus. The measurements were obtained by the Cassini spacecraft’s Composite Infrared Spectrometer from the spacecraft’s close flyby of the moon on March 12, 2008. Credit:NASA/JPL/GSFC/SwRI/SSI
Another discovery by Cassini shows that the so-called tiger stripes, the source of the geysers, are 17 deg C warmer than previously seen and 93 deg C warmer than other regions of the moon. These surprisingly high temperatures make it more likely that there’s liquid water not far below the surface. Enceladus, now joining Jupiter’s moon Europa, to have a subsurface ocean. Another possible place to look for life.
Organic material + warmer temperature + possible liquid water = good place to look for life.
Some essential building blocks needed for life do exist at Enceladus. Although there is no evidence of life there now, but it just don’t stop us from wondering, right?
This is an artist’s concept of Saturn’s rings and major icy moons. Enceladus is located in the densest region of Saturn’s E-ring, possibly indicating there is some relationship between the geyser emissions and ring density. Credit: NASA/JPL
Cassini will return in August for an even more daring, lower flyby of this strange, gassy moon.
Source: NASA Mission News
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