Exactly four years ago I was hosting a standing-room-only crowd of over 600 at the University of Colorado’s Laboratory for Atmospheric and Space Physics for the arrival of Cassini at Saturn. That means that the four-year prime mission is now over and tomorrow begins the Cassini Equinox Mission that takes us through – you guessed it – Saturn’s equinox. That phase of Cassini ends, depending on how you count it, either September 30, 2010, or March 31, 2011. That will certainly not spell the end of the mission overall as the spacecraft will still be merrily orbiting Saturn at the end of the CEM. To avoid any potential contamination of Titan and Enceladus which, due to the presence of organic compounds (Titan) or possibly liquid water (Enceladus), are considered potential abodes for life, Cassini will ultimately be destroyed, probably dumped into Saturn’s atmosphere. That will mark the end of the proposed Cassini Solstice Mission. If approved, this would happen after Saturn’s northern summer solstice in the spring of 2017. Details of that proposed mission are being worked on by the Cassini project now for presentation to NASA late this year or early next year.

In the meantime, more and more scientists are working on the tremendous volumes of data returned by Cassini’s twelve instruments. NASA has funded two rounds of proposals to its Cassini Data Analysis Program and the third round of proposals was just submitted. This summer I’m co-organizing a workshop to discuss the new discoveries related to Saturn’s rings. That will be immediately followed by a symposium to prepare for a book summarizing what we have learned about the Saturn system as a whole.