Washington: NASA's Cassini spacecraft will take final close-up look at Saturn's huge and irregularly shaped moon Hyperion on May 31.
The Saturn-orbiting spacecraft will pass Hyperion at a distance of about 34,000 kilometers at approximately 6:36 a.m. PDT (9:36 a.m. EDT). Mission controllers expect images from the encounter to arrive on Earth within 24 to 48 hours.
Mission scientists have hopes of seeing different terrain on Hyperion than the mission has previously explored in detail during the encounter, but this is not guaranteed, as Hyperion rotates chaotically, essentially tumbling unpredictably through space as it orbits Saturn.
Cassini scientists attribute Hyperion's unusual, sponge-like appearance to the fact that it has an unusually low density for such a large object' about half that of water. Its low density makes Hyperion quite porous, with weak surface gravity.
Before this, Cassini's closest-ever Hyperion flyby took place on September 26, 2005, at a distance of 505 kilometers.