Even when viewed through a typical amateur telescope, Saturn’s rings offer a jaw-dropping spectacle that always satisfies. But looked at through the eyes of NASA’s now-departed Cassini spacecraft, the view is unlike anything else in the solar system, a stunning tapestry of mind-boggling complexity. This image, taken on 22 August, 2009, by Cassini’s narrow-angle camera at a distance of 2 million kilometres (1.27 million miles) employed red, green and blue filters to produce a natural colour view. The rings are made up mostly of water ice, with particles as small as grains of sand and as large as mountains. The precise nature of the icy material that gives the rings their colour remains a topic of debate.
Janus and Tethys demonstrate the main difference between small moons and large ones; it’s all about their shape. Moons like Tethys are large enough that their own gravity is sufficient to overcome the material strength of the substances they are made of and mould them into spherical shapes, but small moons like Janus are not massive enough for their gravity to form them into a sphere.
Saturn’s clouds have roots deeper inside the planet’s atmosphere than scientists previously thought, and Saturn’s rings — now believed to have formed in the last 200 million years — appear to be raining organic molecules down on the planet, according to observations made by NASA’s Cassini spacecraft last year in the final weeks of its mission.
The serene beauty of the International Space Station gliding silently across the sky needs nothing more than the naked eye to appreciate. But when the dazzling ISS is also in conjunction with a partially eclipsed Moon, Saturn and Jupiter on the 50th anniversary of Apollo 11’s launch, be sure to look low in the southeast through south around 10:06pm BST on 16 July 2019!