Tomorrow, on Saturday March 9th, the Cassini probe will take a close look at the surface of Rhea from as little as 1000km away.
Cassini was launched in 1997 and arrived in orbit around Saturn in 2004. It is now on its second mission extension in orbit around Saturn, looking at its great rings and checking out some of Saturns moons.
This close flyby of Rhea is a combination mission, taking a long hard look at the surface of the moon in the visible, infrared and ultraviolet spectra; and measuring the gravitational pull of the moon against its steady radio link to see if Rhea’s structure is homogenous throughout, or stratified like the Earth’s, separated into crust, mantle and core regions.
Cassini will fly within about 600 miles (1,000 kilometers) of the surface. The time of closest approach is around 10:17 a.m. PST (1:17 p.m. EST).
Image: Rhea’s surface during the last close flyby in 2012. Credit: NASA/Cassini