Active moon
Picture of Egelados taken by the Cassini spacecraft. NASA
Despite the success of the Voyager missions, much was still unknown to Egelados. Therefore, NASA designed the Cassini mission. Cassini would orbit Saturn for over a decade, capturing some of the most stunning images of the ringed planet and its moons. Egelados was one of the most visited Cassini worlds. Cassini has revealed a world more bizarre than science fiction. The South Pole of Egelados proved to be its most interesting feature, and was thus observed by Cassini on many occasions. The South Pole of Egelados seemed to launch some kind of material into space. More careful observations revealed that Egelados actually released huge amounts of water vapor into space. This water was ejected by giant geysers located around the South Pole of Egelados. The area was named Tiger Stripes after the large lanes that cross the South Pole. Geysers are generally indications that a world is volcanically active, suggesting that the interior of Egelados is very warm. This came as a surprise, as tiny worlds like Enceladus tend to release their heat into space fairly quickly. This is why most moons, like ours, are covered by craters and have no evidence of recent activity. The fact that such a small world is so active means that Egelados is supplied with large amounts of energy. With the sun too far away to provide enough heat, astronomers looked at Saturn. As Enceladus orbits Saturn, the gravity of the gas giant attracts the small moon. This gradually bends the Enceladus, stretching the moon when it is far away and compressing it when it is close. This bend creates friction in the core of Ekelados, which melts the subterranean rocks and releases heat. This heat melts the subterranean ice to form a subterranean ocean that could be ten times deeper than the deepest ocean on Earth. The warm subterranean ocean partially melts the ice on the surface, creating the large cracks and crevices we can see today. As the heat rises to the surface, it also causes a large explosion of water through the ice in the form of geysers. Some of this water vapor falls back and becomes a cover of fresh snow in Egelados. The rest of the material escapes into space and becomes part of Saturn’s E-Ring.
Habitat of Egelados
Cassini captured this image of geysers exploding in Egelados. NASA
The existence of liquid water in Egelados makes it a potentially habitable world. In addition to liquid water, the Cassini spacecraft also detected organic matter in its geysers, and the geysers themselves suggest that the moon contains enough energy to support life formation. Cassini was able to determine Enceladus’ chemistry by flying through its geysers, sampling water vapor and determining its composition. Unfortunately, Cassini was not equipped with the technology needed to detect living organisms. If there really is life on Enceladus, it is possible for some organisms to be launched into space by geysers. A future mission to Enceladus could fly through the geysers and look for evidence of tiny organisms.
Aidan Remple July 1, 2022 in Science
