NASA's spacecraft Cassini is making its second flyby of Saturn's moon Enceladus on Wednesday, Oct. 28 as it travels through an icy plume in its mission to sample the ocean to provide insights to whether or not there are possible signs of alien life.
Cassini was expected to make its closest approach to Enceladus this morning at 11:22 a.m. ET. At 19,000 mph, the spacecraft made its deepest-ever dive through the ice spray erupting near the south pole of Saturn's moon at only 30 miles above the surface.
Enceladus is only 300 miles across and is covered mostly by ice. It features areas of craters and its plume region in the south that shoots geyser-like jets of water vapor and other material out into space. The icy plume is said to eject about 440 pounds of water vapor every second and is filled with materials from the icy moon's underground ocean that is heated by tidal forces from Saturn and its other moon, Dione.
When there is water, there is the possibility of alien life.
"Enceladus is not just an ocean world — it's a world that might provide a habitable environment for life as we know it," said Curt Niebur, a Cassini program scientist, in a statement on Monday.
However, NASA said that the purpose of the mission is not to detect life, but rather to learn more about the ocean environment within Enceladus. Instead, they are looking for insights to how much hydrothermal activity (chemistry including rock and hot water) is occurring within Saturn's moon. Still, these insights could give scientists implications about whether or not Enceladus could support life.
Along with taking photos during the flyby, Cassini also will use instruments such as a dust analyzer and spectrometer to gather chemical composition data in hopes of finding molecular hydrogen, methane, ethane and hydrocarbons.
The flyby will also help scientists determine if the plume contains "column-like, individual jets," "icy curtain eruptions" or a combination of the two. This would help them figure out just how ocean material is coming to the surface. It may also shed some light on how long Enceladus' ocean might have been active.
Cassini has been orbiting Saturn at a distance of about 980 million miles from the Earth since 2004. It has made dozens of flybys already, today's being the second of the three final missions the spacecraft will conduct before it wraps up its Enceladus mission by the end of the year.
Source: NASA
