E-19 was the third of three fly-bys (along with E-9 andE-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 had its usual three periods of observation: two wings and closest-approach. The fields, particles and waves instruments'pointing was optimized to gather data near closest approach.
- During the dark approach, the composite infrared spectrometer (CIRS) was observing the anti-Saturnian hemisphere to monitor hot spots, and possibly discovering new ones to understand the global energy balance of Enceladus. During the exit leg, CIRS was observing near the equator during the day (again to understand the global energy balance).
- After E-19, there was a 5,010 mile (8,063 kilometer) Dione untargeted flyby with imaging science subsystem (ISS) and CIRS prime. This flyby was 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.
May 2, 2012
46 miles (74 km)
17,000 mph (7.5 km/sec)