Advertisements

Blog Archives

Saturn’s Moon Atlas Is Even More Flying Saucery Than Pan

Animation made from images acquired by Cassini on April 12, 2017.

If you thought Pan resembled a UFO, Atlas is even more saucer-shaped! Slightly larger at about 19 miles across, Saturn’s moon Atlas was passed by NASA’s Cassini spacecraft on April 12, 2017, coming within about 9,000 miles. The images above are a collection of eight from Cassini’s closest approach. Like its smaller sibling Pan, Atlas has a flattened shape, created by the presence of a large buildup of icy material around its equator.

Atlas orbits Saturn just outside the edge of the A ring, taking about 14 hours to complete a full orbit.

Learn more about Atlas here.

UPDATE: Here’s a color image of Atlas made from raw images acquired by Cassini on April 12 in infrared, green, and UV wavelengths. I’ve adjusted it to bring out some surface detail and (hopefully) closer match actual visible light.

Atlas IR--G-UV 4-12-17

Color image of Atlas from April 12, 2017. Credit: NASA/JPL/Caltech/Space Science Institute/Jason Major.

Advertisements

Our Best Ever Look at Pan, Saturn’s Little “UFO”

Images of the shepherd moon Pan captured by Cassini on March 7, 2017. (Credit: NASA/JPL-Caltech/SSI. Animation by Jason Major.)

Behold the almighty Pan! Thanks to Cassini’s ring-grazing orbits we’ve just received the highest-resolution images ever of Pan—which, at only about 17 miles (27 km) across admittedly isn’t very “almighty” but its flying saucer-like shape is really quite fascinating!

The raw images above were acquired by Cassini on March 7, 2017 and received on Earth on March 8. I assembled them into an animation to show some of the 3D shape of the little shepherd moon, which orbits Saturn inside the 200 mile wide Encke Gap in the A ring.

Read the rest of this entry

Ring Racer (Take Two)

I came across this image today while going through the latest Cassini PDS (Planetary Data System) release, and remembered how excited I was to see it the first time when it came in last June. If you missed it, here it is again (with an image fresh off the PDS!)

Daphnis churns up the edges of the Keeler Gap

Man, I just LOVE this stuff. 🙂

This has to be one of the coolest images yet of one of my favorite subjects: Saturn’s moon Daphnis casting a shadow and riling up the rings as it travels along the 26-mile-wide Keeler Gap, a channel it keeps clear around the outer edge of the A ring. The image above is a cropped and rotated version of a raw image sent back from the Cassini spacecraft today.

The four-and-a-half mile wide Daphnis was first seen by Cassini in 2005. Read the rest of this entry

Ring Racer

Daphnis churns up the edges of the Keeler Gap

Man, I just LOVE this stuff. 🙂

This has to be one of the coolest images yet of one of my favorite subjects: Saturn’s moon Daphnis casting a shadow and riling up the rings as it travels along the 26-mile-wide Keeler Gap, a channel it keeps clear around the outer edge of the A ring. The image above is a cropped and rotated version of a raw image sent back from the Cassini spacecraft today.

Daphnis and Pan making waves

The four-and-a-half mile wide Daphnis was first seen by Cassini in 2005. As it travels, its gravity “sculpts” the fine, icy particles along the edge of the gap into scallops, not only horizontally but also vertically, sending waves of ring bits as high as a mile or so above and below the ringplane. This phenomenon became clear as Saturn approached its spring equinox last August, when light from the sun hit the planet parallel to the equator and made small details like this visible because of the shadows they cast. Even now, almost a year later, the angle of the sunlight is still low enough to keep the shadows long…Saturn’s year is 29 Earth years long so it takes much longer than a few months to get from spring to summer.

The original raw image had another treat as well: the larger shepherd moon Pan was also casting its shadow and causing some gravitational streamers of its own along its path in the Encke Gap! Two dynamic moons in one image…ladies and gentlemen this is Cassini at its best!

Image: NASA/JPL/Space Science Institute

Flying Pan

The shepherd moon Pan casts its shadow

Making a complete orbit in just under 14 hours, the 17-mile-wide shepherd moon Pan cruises around Saturn within the Encke gap in the A ring. In the image above, taken by Cassini on January 8, we can see Pan casting a sliver of a shadow onto the outer edge of the gap as it causes faint trailing disturbances behind it along the gap’s inner edge.

Pan shares the 202-mile-wide Encke gap with several thin ringlets too. Its passing seems to have riled up one of the ringlets here, causing it to pick up extra-bright highlighting from the sun.

This image was taken with Cassini’s narrow-angle camera from a position below the ringplane. Some stars are also visible, outside as well as through the rings. Saturn’s own huge shadow darkens the top portion of the image.

Image: NASA/JPL/Space Science Institute

%d bloggers like this: