NASA's Cassini spacecraft, which is currently orbiting Saturn, is set to make its final close flyby of Enceladus, the planet's ocean-bearing moon, on Dec. 19 at 9:49 a.m. PST (12:49 p.m. EST), according to a press release. Although the spacecraft will continue to gather data on Enceladus after the flyby, this will done from much greater distances.
The goal of the upcoming flyby is to measure the heat making its way through the ice from the moon's interior, which is integral in understanding the driving forces behind the gas and icy particles that continue to spray from its subsurface ocean.
"Understanding how much warmth Enceladus has in its heart provides insight into its remarkable geologic activity, and that makes this last close flyby a fantastic scientific opportunity," said Linda Spilker, a Cassini project scientist at NASA's Jet Propulsion Laboratory.
The distance of the flyby - approximately 3,106 miles (4,999 kilometers) - is not the closest that Cassini has conducted, but is optimal for its Composite Infrared Spectrometer (CIRS) instrument to gain accurate heat flow measurements.
"The distance of this flyby is in the sweet spot for us to map the heat coming from within Enceladus - not too close, and not too far away. It allows us to map a good portion of the intriguing south polar region at good resolution," said Mike Flasar, CIRS team lead at NASA's Goddard Space Flight Center.
The observations will take place during the southern hemisphere's winter cycle, which creates exemplary conditions for the mission due to the lack of sunlight making it ideal for the detection and differentiation of heat, according to Gizmag.
