Cassini will fly through a plume of icy spray from Saturn's moon, Enceladus, on Wednesday, Oct. 28, according to a press release. NASA is holding a teleconference on Monday, Oct. 26 to talk about anticipated results and plans for the flyby.
The conference will take place at 11 a.m. PDT (2 p.m. EDT, 18:00 UTC). Participants will include:
* Curt Niebur, Cassini program scientist at NASA Headquarters in Washington D.C.
* Earl Maize, Cassini project manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif.
* Linda Spilker, Cassini project scientist at JPL
You can be a part of the conversation by using the hashtag #askNASA on social media during the conference.
NASA JPL Live via UStream
"The spacecraft will make its closest approach to Enceladus at 8:22 a.m. PDT (11:22 a.m. EDT) Wednesday at an altitude of 30 miles (49 kilometers) above the moon's south polar region. The encounter will be Cassini's deepest-ever dive through the Enceladus plume, and is expected to provide valuable data about activity in the global ocean stirring beneath the moon's frozen surface.
"Cassini scientists are hopeful the flyby will provide insights into how much hydrothermal activity is occurring within Enceladus, and how this hot-water chemistry might impact the ocean's potential habitability for simple forms of life. If the spacecraft's ion and neutral mass spectrometer instrument (INMS) detects molecular hydrogen as it travels through the plume, scientists may get the measurements they need to answers these questions.
"'Confirmation of molecular hydrogen in the plume would be an independent line of evidence that hydrothermal activity is taking place in the Enceladus ocean, on the seafloor,' said Hunter Waite, INMS team lead at Southwest Research Institute in San Antonio. 'The amount of hydrogen would reveal how much hydrothermal activity is going on.'"
"Using Cassini's cosmic dust analyzer (CDA) instrument, scientists expect the flyby will lead to a better understanding of the chemistry of the plume. The low altitude of the encounter is, in part, intended to increase the spacecraft's access to heavier, more massive molecules -- including organics -- than the spacecraft has observed during previous, higher altitude passes through the plume. The CDA instrument, which is capable of detecting up to 10,000 particles per second from the plume, also is expected to reveal how much material the plume is spraying from the moon's ocean into the space around Saturn.
"'There's really no room for ambiguity,' said Sascha Kempf, a CDA team co-investigator at the University of Colorado at Boulder. 'The data will either match what our models are telling us about the rate at which the plume is producing material, or our concept of how the plume works needs additional thought.'"
The last of Cassini's three close flybys will be on Dec. 19, when the heat from the moon's interior will be examined.