Keeping you current

See Three of Saturn’s Moons Pose in a Family Photo

While in orbit, Cassini captures a stunning shot of three crescents

The Cassini spacecraft took this image of three of Saturn's moons, Rhea, Mimas and Titan. (NASA/JPL-Caltech/Space Science Institute)
smithsonian.com

The Cassini orbiter has captured three of Saturn’s 62 moons — Titan, Mimas and Rhea — in one stunning image, as Michael Zhang reports for PetaPixel.

On its ongoing mission to study Saturn and its moons, the probe snapped the image with its narrow angle camera in visible light back in March. At the time, Cassini was 1.2 million miles away from Titan, 1.9 million miles away from Mimas and 2.2 million miles away from Rhea. NASA released the image last week.

Among Saturn's 62 moons (that scientists know know about), 53 have names. For Earth-dwellers, the image is a rare glimpse of a night sky that’s illuminated by more than one crescent, as Zhang points out.

The tiniest of the three moons in the photograph, Mimas, is just 246 miles in diameter. For comparison, our moon's diameter is a whopping 2,160 miles. A large bulls eye crater gives Mimas the look of the death star from Star Wars, as Rachel Feltman points out for the Washington Post. Rhea, Saturn’s second largest moon, is 949 miles across. Icy, rocky craters pockmark its surface, giving Rhea a rough appearance in the image.

If Titan, Saturn’s largest moon at about 3,200 miles in diameter, looks a bit blurry in the image, that’s because only its cloud layers are visible. Its atmosphere is quite thick, as Feltman notes, and refracts light. That’s why Titan’s crescent extends a little bit longer around the moon than it would on a planetary body without an atmosphere.

About Helen Thompson
Helen Thompson

Helen Thompson writes about science and culture for Smithsonian. She's previously written for NPR, National Geographic News, Nature and others.

Read more from this author |
Tags

Comment on this Story

comments powered by Disqus