Round and round they go… the animation above, made from 14 raw images taken by NASA’s Cassini spacecraft on August 23, 2016, shows the moons Prometheus and Atlas orbiting Saturn within the Roche Division gap between its A (top right) and F (center) rings. The gravitational tug of Prometheus (92 miles / 148 km long) is strong enough to pull on the fine, smoke-like icy particles of the F ring, creating streamer and “clump” features that follow it along.
The much smaller Atlas (23 miles / 37 km wide) follows a path around Saturn just past the outer edge of the A ring. It was once thought to be a “shepherd moon” of the A ring, but it’s now known that the pull of the more distant Janus and Epimetheus are responsible for that.
Atlas does have its very own ring, though—a very faint (i.e., not visible above) band of material that runs along its orbit named R/2004 S 1, discovered by the Cassini mission in July 2004.
Image credit: NASA/JPL-Caltech/SSI. Animation by Jason Major.
Five years ago today, at 10:23 a.m. EST on Feb, 11, 2010, NASA’s Solar Dynamics Observatory launched aboard an Atlas V rocket from Cape Canaveral Air Force Station, sending the most advanced solar observatory satellite into orbit and giving us an amazing new look at our home star. Since then SDO has been monitoring the Sun on a constant minute-by-minute basis, sending back terabytes of data and capturing 200 million images over 1,826 days in space, 22,300 miles from Earth.
The video above is an homage to SDO from the team at NASA’s Goddard Space Flight Center in Maryland. Here’s to five amazing years and hopefully many more ahead! Learn more about SDO and get the most up-to-date images and information here.
Also, watch the 2010 launch of SDO below:
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 shapes.
This brief animation, made from 33 raw images captured by Cassini on December 26 (otherwise known locally as my birthday!) shows the F ring in action as it follows shepherd moons Prometheus and smaller Atlas around Saturn. Some motion is due to the orbits of the rings and moons, and some is due to the spacecraft itself.
You can watch a slower version of the animation below:
Cassini’s at it again! After its last flyby of Titan the spacecraft changed course, heading up and away from Saturn’s equatorial plane at an angle that will allow it to better study the rings and the planet’s polar regions.
This raw image, captured on May 23, shows Cassini’s view as it heads upwards. It shows a view of Saturn’s rings and two shepherd moons, Pandora (foreground) and Atlas.
It’s nice to see some views like this again from Cassini!