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.
In recent nights, observers in the UK and Western Europe have seen the International Space Station (ISS) as a bright naked-eye ‘star’ moving slowly across the sky from west to east. On Thursday, 9 June, London is favoured for some close approaches of the ISS to the Moon, Jupiter and Saturn. If you see the Station, spare a thought for Tim Peake and the Expedition 47 crew on board!
The shadow of Saturn’s globe on the rings, which stretched across all of the rings earlier in the Cassini spacecraft’s mission, now barely makes it past the Cassini Division. The changing length of the globe’s shadow marks the passing of the seasons on Saturn. As the planet nears its northern-hemisphere solstice in May 2017, the shadow will get even shorter.
