This image from NASA’s Cassini spacecraft shows three moons — Rhea (top), Titan and Mimas (bottom). Titan appears fuzzy because we only see its cloud layers and light refracts within its atmosphere, extending the crescent. Image credit: NASA/JPL-Caltech/Space Science Institute.The three moons shown here — Titan (3,200 miles or 5,150 kilometres across), Mimas (246 miles or 396 kilometres across), and Rhea (949 miles or 1,527 kilometres across) — show marked contrasts. Titan, the largest moon in this image, appears fuzzy because we only see its cloud layers. And because Titan’s atmosphere refracts light around the moon, its crescent “wraps” just a little further around the moon than it would on an airless body. Rhea (upper left) appears rough because its icy surface is heavily cratered. And a close inspection of Mimas (centre bottom), though difficult to see at this scale, shows surface irregularities due to its own violent history.
This view looks toward the anti-Saturn hemisphere of Titan. North on Titan is up. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 25, 2015.
The view was obtained at a distance of approximately 1.2 million miles (2.0 million kilometres) from Titan where the image scale is 75 miles (121 kilometres) per pixel. Mimas was 1.9 million miles (3.1 million kilometres) away with an image scale of 11.4 miles (18.4 kilometers) per pixel, while Rhea was 2.2 million miles (3.5 million kilometres) away with an image scale of 13.1 miles (21.1 kilometres) per pixel.
Observers in Western Europe with a clear sky around local midnight cannot fail to notice the conspicuous ‘star’ that is Jupiter low in the south. But look a span-and-a-half of an outstretched hand at arm’s length to Jupiter’s left and you’ll find another giant of the solar system – Saturn. The ringed planet is closest to Earth for 2019 on 9 July, so here is our quick observing guide.
Two tiny moons of Saturn, almost lost amid the planet’s enormous rings, are seen orbiting in this Cassini probe image. Pan, visible within the Encke Gap near lower-right, is in the process of overtaking the slower Atlas, visible at upper-left.
In this image from NASA’s Cassini spacecraft, Saturn’s moon Dione reveals its past via contrasts. The features visible here are a mixture of tectonics — the bright, linear features — and impact cratering — the round features, which are spread across the entire surface.
