The Cassini spacecraft, orbiting around Saturn, has discovered at least 101 geysers on the icy moon of Enceladus.
Cassini mission planners were able to identify 101 individual geysers on the surface of the alien moon. The active features were discovered near the southern pole of the satellite, which has a diameter about 15 percent as wide as our moon.
Water from an underground ocean may be feeding the polar geysers on the Saturnian moon. This could suggest a mechanism for liquid water to be replenished on the surface of the world. Many astrobiologists believe the substance is required as a medium in which life can form.
Enceladus is the sixth-largest Moon of Saturn, and was first discovered by the astronomer William Herschel in 1789. Astronomers were unable to gain much detailed information about the satellite until the system was visited by the two Voyager spacecraft a little over three decades ago. The surface of the world is so bright, it reflects nearly 100 percent of the light that strikes the celestial body.
Excess heat was first detected emanating from the south pole of Enceladus in 2010, which was thought to lead to the formation of geysers. One idea stated that tidal forces, created as the moon circled the giant ringed planet, may have caused faults near the pole to slip, creating frictional heating. Other astronomers believed the faults themselves opened and closed, releasing water from beneath the surface which had been under pressure.
Since that time, astronomers have learned the water spouts themselves are the source of the heat, warming the region around the features.
The south pole of Enceladus is marked by four distinct fractures, shaped like the stripes of a tiger. Ice erupts from small geysers that run along the geological feature. Cassini mapped the area over multiple close encounters with the world, completed over seven years. It was from this composite image that astronomers were able to identify the 101 geysers.
Researchers used triangulation - a geometric technique used for land surveys on Earth - to precisely locate geysers on the moon. They them compared this data to low-resolution images of hot spots near the poles, and the locations matched up almost perfectly. High-resolution thermal photographs obtained by Cassini confirmed the finding.
Once we had these results in hand, we knew right away heat was not causing the geysers, but vice versa. It also told us the geysers are not a near-surface phenomenon, but have much deeper roots," Carolyn Porco, leader of the Cassini imaging team, said.
Water is now considered, by many astrobiologists, to be a prerequisite for life. This new discovery opens up the possibility it may have florished there either now, or in the distant past.
A pair of articles were published in The Astronomical Journal, describing discovery of the geysers, and possible causes of their activity.
