A Close Pass of Helene
On June 18, 2011, the Cassini spacecraft performed a flyby of Saturn’s moon Helene. Passing at a distance of 4,330 miles, it was its second-closest pass of the icy little moon.
The image above is a color composite made from raw images taken in the red, green and blue visible light filters. There’s a bit of a blur because the moon shifted position in the frames slightly between images, but I think it captures some of the subtle color variations of lighting and surface composition nicely!
(By the way, north on Helene is facing down in these images.)
Also, here’s a 3D anaglyph view of Helene made from the recent raw images by Patrick Rutherford, my workmate:
The curious petal-shaped “gullies” on the front-facing surface of Helene are most likely caused by material having slid downslope as the result of impacts.
Helene orbits Saturn at the considerable distance of 234,505 miles (377,400 km). Irregularly-shaped, it measures 22 x 19 x 18.6 miles (36 x 32 x 30 km).
Images: NASA / JPL / Space Science Institute. Edited by J. Major and P. Rutherford.
UPDATE 6/5/18: Here’s an animation of raw images taken during the pass: