Rhea Eclipses Dione While Cassini Watches

It’s been a while since I last made one of these: it’s an animation comprising 27 images acquired by Cassini in various color channels on October 11, 2015. It shows Saturn’s second-largest moon Rhea passing in front of the smaller and more distant* Dione, both partially illuminated by sunlight. I cleaned up some image artifacts…

Cassini Captures Narrow-Angle, Wide-Spectrum Views of Rhea

After spending a couple of years in an orbit riding high over the northern pole of Saturn Cassini has swung back down alongside the planet’s ringplane, in perfect alignment to once again capture views of the icy moons that reside there. The image above is a composite made from several narrow-angle camera images acquired by Cassini on…

The Color of Rhea

If someone were to ask you today what the most heavily-cratered world in the Solar System is, you can’t go wrong with saying “why, Rhea of course!” (I don’t know why someone would ask you that, but if anyone does you can now consider yourself well-prepared.) 🙂

Rugged Rhea

Here’s a color-composite image of Rhea, made from raw images acquired by Cassini during a flyby on March 10, 2012. The color is derived from images taken in infrared, green and ultraviolet light.

Ride Along With Rhea

Assembled from 29 raw images taken by the Cassini orbiter on Monday, April 25, this animation brings us along an orbital ride with Rhea as it crosses Saturn’s nighttime face, the planet’s shadow cast across the ringplane. Sister moons Dione and Tethys travel the opposite lane in the background, eventually appearing to sink into Saturn’s…

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…

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…

A Rhea View

Here’s an amazingly detailed view of the extensively cratered surface of Rhea, Saturn’s second-largest moon, taken during a particularly close encounter by Cassini on October 13, 2009. About 950 miles wide Rhea is less than a third the size of Titan, Saturn’s largest moon. Unlike Titan, Rhea has no atmosphere at all to speak of…

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…

Sometimes it Rains on the Sun

(Updated post from 2013) The Sun is awesome. I mean, never mind that it contains 99% of all the mass in the Solar System, that it supplies our planet with the energy needed to sustain life, that its constantly-blowing solar wind helps keep some of those nasty cosmic particles out of the planetary neighborhood, and…

Answers to 8 Questions About the August 2017 Solar Eclipse

It’s August and one of the most highly-anticipated astronomical events of the 21st century is nearly upon us: the August 21 solar eclipse, which will be visible as a total eclipse literally across the entire United States…but that doesn’t mean everywhere in the United States. Totality will pass across the U.S. in a narrow band about…