A thrilling ride is about to begin for NASA’s Cassini spacecraft. Engineers have been pumping up the probe’s orbit around Saturn this year to increase its tilt with respect to the planet’s equator and rings. And on 30 November, following a gravitational nudge from Saturn’s moon Titan, Cassini will enter the first phase of the mission’s dramatic endgame.
After more than 12 years studying Saturn, its rings and moons, NASA’s Cassini spacecraft has entered the final year of its epic voyage. The Grand Finale will come on 15 September 2017 as Cassini dives into Saturn’s cloud tops, where friction with the atmosphere will cause the spacecraft to burn up like a meteor.
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.
NASA’s Cassini spacecraft spied details on the pockmarked surface of Saturn’s moon Prometheus (86 kilometres, or 53 miles across) during a moderately close flyby on 6 December 2015. This is one of Cassini’s highest resolution views of Prometheus, a moon which orbits Saturn just interior to the narrow F ring, which is seen here at top.
Researchers at Kobe University have used computer models to reveal that Saturn’s F Ring and its shepherd satellites are a natural outcome of the final stage of the planet’s satellite system. This new finding is expected to help elucidate the formation of satellite systems both within and outside our solar system.