Mar 12, 2008 02:00:48 PM
Amanda Hendrix, Cassini Scientist on the Ultraviolet Imaging Spectrograph (bio)
Well our flyby sequence has officially started!! Last night we began our observations of Enceladus! We are very distant, but getting closer all the time, over the northern hemisphere. The first observation was a long stare at Enceladus, which is still pretty far away and small, but this is a nice opportunity to do compositional measurements. As of 9 a.m. Pacific, radar observation of Enceladus began, which will give us an idea of the roughness of this side of Enceladus, at centimeter scales. The closest approach is around 1 p.m. Pacific today.
The entire flyby sequence is on-board the spacecraft, and there's really no opportunity to change it at this point. We're in it for good. However, the sequence gets thoroughly tested prior to uplink, so we are confident that things will go smoothly. The next time we hear from Cassini will be tonight after the flyby at around 7 p.m. Pacific. We are being fairly cautious, though: even though Cassini will come about 30 miles of the surface, while flying through the plume we will be 120 miles from the surface. So we're "dipping our toes" in the plume a little more than we've done before!
Cheers from Houston,