Cassini Enceladus Flyby – May 2, 2012

nceladus ‘E-19’ Flyby: Completing the Trilogy

E-19 is the third of three fly-bys (along with E-9 and E-12 designed to understand the internal structure of Enceladus, particularly the concentration of mass under the south polar region. Data collected in this area may provide insight into the plume activity on the moon. During E-19, radio science (RSS) will have its usual three periods of observation: two wings and closest-approach. The fields, particles and waves instruments’ pointing will be optimized to gather data near closest approach.

Other highlights:

* During the dark approach, the composite infrared spectrometer (CIRS) will be observing the anti-Saturnian hemisphere to monitor hot spots, and discover new ones to understand the global energy balance of Enceladus. During the exit leg, CIRS will be observing near the equator during the day (again to understand the global energy balance).

* After E-19, there is a 5,010 mile (8,063 kilometer) Dione untargeted flyby with imaging science subsystem (ISS) and CIRS prime. This flyby is designed to seek hot spots and possible emission from Dione, and to map poorly observed regions.

* Other observations include a plume observation similar to one taken on the previous pass, to understand plume variability on the scale of weeks; and two 10-hour irregular satellite observations to derive their lightcurve and rotational states, to give further information on the collisional environment in the outer Saturnian system.

Enceladus Flyby at a Glance

Date May 2, 2012 (SCET)

Altitude 46 miles (74 kilometers)

Speed 17,000 mph (7.5 km/sec)