Watch Two Dark Moons Sneak Into Cassini’s Shots

On March 11, NASA’s Cassini spacecraft was acquiring some images of Saturn’s back-lit limb when two of its moons decided to make an entrance. Like stage hands in a darkened theatre the moons quickly passed  across the scene, moving between Saturn and the spacecraft and, because of exposure time and spacecraft motion, getting a bit blurred in the process.

In the image above the silhouette of one moon can be seen at bottom right — Mimas, perhaps — while another’s crescent can be made out at upper left… possibly Enceladus. Very cool!

Watch an animation of the moons below:

Two of Saturn’s moons drift into the scene on March 11, 2014 (NASA/JPL-Caltech/SSI. Animation by Jason Major.)

While I admit I’m not 100% sure which moons these are, based on their apparent shapes, positions, and relative sizes I’d make my guess that these are 318-mile (511-km) -wide Enceladus and the 246-mile (395-km) -wide Mimas.

Possible location of icy spray, if Enceladus is in fact this moon’s real name

Cassini was 843,762 miles (1,357,903 km) from Saturn when the images were acquired. And, if the larger moon at left is Enceladus, I’m thinking south in these images is up based on the barely-perceptible presence of a lighter area along its top edge that could be icy spray from its southern geysers. (See enlarged detail at right.)

Saturn, of course, is on the right. A small segment of the bright arc of its backlit limb is what’s running diagonally down across the image.

These images have not yet been calibrated or cataloged by NASA or the Cassini team.

See the latest raw images from Cassini on JPL’s mission page here.

*I say “dark moons” but actually Enceladus and Mimas are pretty bright, both being composed of a lot of ice. Enceladus is actually the most reflective world in the Solar System!

Jason Major

A graphic designer in Rhode Island, Jason writes about space exploration on his blog Lights In The Dark, Discovery News, and, of course, here on Universe Today. Ad astra!

Recent Posts

Volcanoes on Mars Might Still be Active

Back in March, NASA's InSight lander detected two large quakes from a geologically active region…

8 hours ago

Mars Helicopter Completes its 4th Flight. 117 Seconds of Airtime

NASA's Ingenuity Mars Helicopter just completed its fourth flight, once again setting records for extraterrestrial…

1 day ago

We Could Detect Extraterrestrial Satellite Megaconstellations Within a few Hundred Light-Years

If an alien civilization has a Starlink-like constellation of satellites, we might be able to…

1 day ago

What we’ve Learned About Venus From the Parker Solar Probe

The Parker Solar Probe has been getting in a lot of extracurricular activity lately.  Originally…

2 days ago

One Full Year of Seismic Data Collected by Mars Insight Includes 500 Quakes

The English vocabulary has some words that only make sense from an Earth-bound perspective.  Earthquake…

2 days ago

SpaceX’s SN15 Starship Prototype Nails It!

On the fifth attempt, SpaceX nailed the high-altitude flight test with a Starship prototype! Onward…

3 days ago