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Liquid on Titan, Returning to Enceladus, and a Dedication

Greetings from the "flight deck" of Cassini, one month into the Cassini Equinox Mission! These last four weeks have passed very quickly, and we certainly hit the ground running with essentially no down time between the prime and extended missions. In fact, in the six-week period starting July 1, 2008, we will execute two targeted flybys (Titan and Enceladus) and sixteen non-targeted, more distant satellite flybys. These non-targeted encounters include one liaison each with Methone, Pandora, Janus, Mimas, Atlas, and Titan and two trysts each with Epimetheus, Daphnis, Prometheus, Pallene, and Pan. With sixty-four moons and counting, there's never a shortage of rich scientific targets in the Saturnian system. In fact, as I write this, we just started receiving data from yet another successful close encounter with Titan, a 1623-kilometer (1008-mile) altitude gravity science pass setting up a thrilling Enceladus flyby (E4) on August 11, 2008. Members of the Cassini team (including yours truly) will be blogging during the days around E4, just as we did back in March. Please stay tuned!

As if to reclaim the spotlight currently focusing on Enceladus, Titan recently made the news, yet again, with a profound discovery from Cassini. After many years and much speculation, the presence of liquid ethane in hydrocarbon lakes on Titan has been proved! In an upcoming "Nature" article, coincidentally to be published this very day, Cassini scientists lay out the evidence for the presence of ethane, thanks to observations from the Visual and Infrared Mapping Spectrometer (VIMS). Sounding like a sixth Great Lake, Ontario Lacus, in Titan's south polar latitudes, contains not only ethane but methane, nitrogen, and other hydrocarbons as well. This distant "pond" is actually roughly the size of Lake Ontario on the home planet, but there the similarities end, largely due to the bitter liquid temperatures of 93 Kelvin (-180 degrees Celsius, or -292 degrees Fahrenheit!). Even more bizarrely, Cassini observed Ontario Lacus' lakeside beach becoming more exposed as the lake evaporates into Titan's frigid atmosphere! Clearly, Titan has many puzzles awaiting our eager eyes in the Equinox Mission.

I'd like to close out this column with a dedication. Last week, my paternal grandmother, Alice Rose (Feezor) Barber passed away. She saw unfathomable changes in her lengthy ninety-three years, from the beginnings of radio, air travel, and automobiles all the way through spaceflight. I know her adventuresome spirit and the strong will that saw her through the Great Depression and Dust Bowl in Kansas courses through my veins and permeates my DNA. We shared a passion for travel and exploration, both of us realizing our childhood dream of visiting all fifty states, for example. She was fascinated by our work at JPL and NASA, too, always serving as a proud Gramma and a space ambassador to her fellow patrons in the WaKeeney, KS coffeeshop. As she always told me, "I don't understand everything you're doing, but I'm proud of you." I'd like to say, Gramma, I'm proud of YOU and your rich legacy. I love you with all my heart, and may you rest in eternal peace.