For those who are hoping to find evidence of life somewhere else in the Solar System, there was some exciting news this week. Two moons, Europa and Enceladus, were already thought to be among the best places to search, since both have liquid water oceans beneath their outer icy shells. And now, new data from the Cassini spacecraft and the Hubble Space Telescope has increased the potential for some form of living organisms to be found.
When it comes to places in the Solar System to search for possible alien life, Saturn’s moon Enceladus is now right near the top of the list. Like Jupiter’s moon Europa, it has a subsurface ocean of water, and even plumes/geysers of water vapour which erupt from fissures in the icy surface near the south pole. Those plumes contain organics as discovered by the Cassini probe and there is evidence for hydrothermal activity on the ocean floor, just like on Earth. The fissures are warmed by heat from below, and now there is evidence that some of them are even warmer than expected, meaning that water could be closer to the surface than previously thought.
The Cassini spacecraft has successfully completed its first close pass of Saturn’s ring system, part of the Ring-Grazing Orbits phase of its mission, NASA said yesterday. As might be expected, Cassini has sent back some spectacular new images; these first images show Saturn’s northern hemisphere in incredible detail, including the famous “hexagon” jet stream surrounding the north pole.
As reported earlier this week, the Cassini spacecraft is now preparing to make a series of very close passes by the edges of Saturn’s rings, known as Ring-Grazing Orbits. A couple days ago, Cassini conducted a close flyby of Saturn’s largest moon Titan; this is the second-to-last ever flyby of Titan before Cassini enters the Grand Finale phase of its mission, culminating in a deliberate plunge into Saturn’s atmosphere on Sept. 15, 2017. During this flyby, Cassini focused on mapping the surface and surface temperatures and used Titan’s gravity to help place the spacecraft into the Ring-Grazing Orbits.
A beautiful image of Saturn’s moon Enceladus with its active water vapour geysers, taken by the Cassini spacecraft. The left side of the moon is lit by the Sun and the right side is illuminated by light reflected from Saturn, or “Saturnshine.” The geysers, over 100 known, originate from a subsurface global ocean and are known to contain water vapour, ice particles, salts and organics. The water vapour reaches the surface through cracks in the outer icy crust.