NASA's Cassini spacecraft successfully flew by Saturn's moon Iapetus at a distance of 123,400 kilometers (76,700 miles) on Friday, Dec. 31. NASA's Deep Space Network tracking station in Goldstone, Calif., received the signal and science data that day beginning at 11:47 p.m. Pacific Standard Time.
Iapetus is a world of sharp contrasts. The leading hemisphere is as dark as a freshly-tarred street, and the white, trailing hemisphere resembles freshly-fallen snow.