A Sphere of Ice

Here’s a wonderfully crisp portrait of Saturn’s moon Rhea, taken by Cassini on October 17, 2010 at an altitude of 24,300 miles. Illuminated on the right by sunlight, the left hemisphere is dimly lit by reflected light from Saturn. Rhea is Saturn’s second-largest moon after Titan, but at 950 miles across (compared to 3,200) Rhea is…

Wispy Lines

A closer look at the surface of Rhea, Saturn’s second-largest moon, reveals some of its signature “wispy lines”…the bright exposed faces of steep cliffs on the icy 950-mile-wide moon. Taken by the Cassini spacecraft on June 3, 2010, the image above has been level-adjusted to bring out surface details. Being composed of 75% water ice,…

Peekaboo Moon

Here’s another color composite from Cassini, showing Rhea on the far side of the rings, its northern tip peeking through the Cassini Division. (I’m not 100% sure what smaller moon that is on the left, but my guess is either Janus or Epimetheus.) What I find interesting in this image is the bright streak within…

Skimming the Rings

Saturn’s second-largest moon Rhea passes across the face of the ringed planet in this image, color-combined from three raw images taken by Cassini on May 8, 2010. The rings are seen on edge here, a dark horizontal stripe running underneath the cratered 950-mile-wide moon, their wide shadows cast onto Saturn’s atmosphere below. I really love…

Rhea and the Rings

This is one of those sublime photos from Cassini that just make me smile. Taken on March 24, this raw image shows Rhea, Saturn’s second-largest moon, suspended in orbit in front of the twilight side of Saturn, its rings reduced to a thin ribbon of bands at this viewing angle. The width of the rings…

I can has craters?

Looking like sand on a beach after a hard rain, the surface of Rhea is literally coated with craters of all sizes, to the point where it’s hard to tell where one ends and another begins. These raw images are fresh in from Cassini’s flyby of Saturn’s second-largest moon, which occurred yesterday. The spacecraft passed…

Big Sisters

Rhea and Titan, Saturn’s two largest moons, align in Cassini’s lens in this image taken on November 19, 2009. I level-adjusted and rotated the original raw image file…”north” would be to the right in this view. Rhea is 949 miles wide, cold, icy and airless. Titan, 3,200 miles wide, is also frigidly cold but is…

Enceladus and Rhea

In another stately pas de deux as seen from the point of view of the Cassini spacecraft, moons Rhea and Enceladus slip past each other in their eternal travels around Saturn. This animation is made up of 20 raw images from Cassini, taken on November 15, level-adjusted and rotated 90º clockwise. Enceladus is about to…

Composition in White

949-mile-wide Rhea floats in front of the rings and the brightly-lit face of Saturn in this image from Cassini, taken on November 8. The face of Saturn, overexposed here in order to see detail in the rings and Rhea, appears as bright white, making a dramatic studio backdrop. The planet’s uppermost atmospheric haze is also…

A Passing of Spheres

Rhea overlaps sister moon Dione in this image, taken by Cassini on October 22. One of a series of raw images showing the moons approach and then pass each other. Even at their closest passing the two moons are separated by more than 90,000 miles. Image: NASA/JPL/SSI

It’s a Marvelous Night for a Moondance

In another animation made from raw images taken by Cassini, Mimas passes in front of Rhea (?), whose face is partially covered by Saturn’s rings…which in turn are darkened by the shadow of the planet itself. I removed distracting background stars, as well as dust and streaks often seen in raw photos. Rhea is 950…

Rhea View

A fascinating bit of work by Gordan Ugarkovic, this is a brief false-color animation of 950-mile-wide Rhea, second-largest moon of Saturn. Rhea is very reflective, indicating that it is made up of a lot of water ice, and is also heavily cratered (clearly evident here.) Water ice behaves like rock at the low temperatures that…