Saturn’s F ring is a fascinating structure. Made of fine icy particles — most no larger than the particulates found in cigarette smoke — it orbits Saturn just outside the A ring and is easily perturbed by the gravity of nearby moons and embedded moonlets, which create streamers and clumps that rise up in fanciful…
Category: Saturn’s Moons
Cassini’s Christmas Gift: a Peek at Prometheus
Captured on Christmas Day, this is a raw image from Cassini showing Saturn’s F ring buckling inwards at two places due to the gravitational tug of its inner shepherd moon, Prometheus, seen at center. As the irregularly-shaped moon approaches the ring material in its looping orbit around Saturn it draws material from the ring in…
A Colorful Christmas Moon
Merry Christmas and happy holidays everyone! Here’s your present from Lights in the Dark: a color-composite of Saturn’s moon Dione, lovingly made from raw images captured by the Cassini spacecraft on December 23. 700 miles (1120 km) wide, Dione (pronounced DEE-oh-nee) is covered pole-to-pole in craters and is crisscrossed by deep chasms and long, bright…
A River Runs Through It (and when I say “It” I mean Saturn’s moon Titan)
No, you’re not looking down at the Amazon or the Nile (although the confusion would be understandable)… this is actually a river on an entirely different world: Saturn’s moon Titan! Radar imaging by NASA’s Cassini spacecraft has revealed what appears to be a long river system, complete with side-branching tributaries, meandering across the surface of…
Titan: Dabbling in the Occult
Back in December of 2001, Saturn’s moon Titan passed in front of two background stars (called an “occultation”) from the point of view of the Hale Telescope at Palomar Observatory. Astronomers used the incredible resolving ability of the 5-meter telescope’s adaptive optics to watch the event, which revealed the diffraction of the stars’ light through…
Daphnis Is Back!
It’s been a while since I posted an image of my favorite moon of Saturn, but while looking through some recent raw images returned by the Cassini spacecraft I spotted it: Daphnis, the little sculptor shepherd moon!
Titan: Saturn’s Glow-In-The-Dark Moon
Titan just never ceases to amaze. Saturn’s largest moon, it’s wrapped in a complex, multi-layered nitrogen-and-methane atmosphere ten times thicker than Earth’s. It has seasons and weather, as evidenced by the occasional formation of large bright clouds and, more recently, an area of open-cell convection forming over its south pole. Titan even boasts the distinction…
Cassini Peeks at Titan’s Southern Vortex
A color-composite image of Titan shows Saturn’s largest moon in true color, including its recently-discovered southern vortex forming above its south pole. The image was assembled from three raw images acquired on August 28 by NASA’s Cassini spacecraft in red, green and blue visible light color channels. The background was extended in size to better…
Dione in Color
Although made mostly of ice and rock, Saturn’s moon Dione (pronounced DEE-oh-nee) does have some color to it — although mostly chilly hues of steel blue, as seen in this color-composite made from raw images acquired by Cassini on July 23.
Titan’s Beautiful, Boiling Southern Vortex
Thanks to Cassini’s new vantage point granted by its inclined orbit researchers have gotten a new look at the south pole of Titan, Saturn’s largest moon. What they’ve recently discovered is a swirling vortex of gas forming over the moon’s pole, likely the result of the approach of winter on Titan’s southern hemisphere. Read the…
The Colors of Titan and Saturn
The pumpkin-orange colors of Titan’s thick clouds appear in stark contrast in front of the limb of Saturn, which appears quite blue along its sunlit limb due to Rayleigh scattering, the same process that makes the sky look blue here on Earth. The image here is a color composite made from three separate raw images…
More Evidence for Titan’s Underground Ocean
As Titan travels around Saturn during its 16-day elliptical orbits, it gets rhythmically squeezed by the gravitational pull of the giant planet — an effect known as tidal flexing. Now, if this cloud-covered moon were mostly composed of rock, the flexing would be in the neighborhood of around 3 feet (1 meter.) But based on measurements…
Lights in the Dark 