Now, the mission has just released tantalizing footage of Saturn's moon Janus, which is about 111 miles across, overtaking another of the planet's larger moons, Rhea, about 949 miles across. The video is actually 12 frames snapped by Cassini over a 24-minute period on November 8, 2009.
Scientists later reformatted the series of images on a computer to smooth out the moons' motions between the frames. Janus is the tiny white dot coming from the far left to the far right, about 1.4 million miles away from the spacecraft, while Rhea was about 1.2 million miles away from it. Janus orbits Saturn at about 36,000 miles per hour, double the speed of Rhea. For a better, slower version of the video, go to this page and click on "Flash 2.0 MB."
"As yet another year in Saturn orbit draws to a close," said Cassini imaging team leader Carolyn Porco, "these wondrous movies of an alien place clear across the solar system remind us how fortunate we are to be engaged in this magnificent exploratory expedition."