Saturn’s icy 246-mile-wide moon Mimas (near lower left) appears tiny by comparison to the planet’s rings, but scientists think the all of the small, icy particles spread over a vast area that comprise the rings are no more than a few times as massive as Mimas. The view was obtained by NASA’s Cassini spacecraft at a distance of approximately 564,000 miles from Saturn.
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.
The atmosphere of the planet Saturn has a wider, more intense jet stream than all the planets in the solar system. Winds gusting at speeds of up to 1,025 miles per hour blow from west to east in the equatorial atmosphere, thirteen times the strength of the most destructive hurricane force winds that form on the Earth’s equator.
NASA’s Cassini spacecraft watched clouds of methane moving across the far northern regions of Saturn’s largest moon, Titan, on 29 and 30 October 2016. Several sets of clouds develop, move over the surface and fade during the course of a movie sequence spanning 11 hours, with one frame taken every 20 minutes. These clouds are measured to move at a speed of about 14 to 22 miles per hour.
Scientists are investigating potential causes for the change in colour of the region inside the north-polar hexagon on Saturn, thought to be an effect of the planet’s seasons. In particular, the change to a more golden hue may be due to the increased production of photochemical hazes in the atmosphere as the north pole approaches summer solstice in May 2017.
In the race towards the discovery of Planet Nine, scientists from around the world strive to calculate its orbit using the tracks left by the small bodies that move well beyond Neptune. Now, astronomers from Spain and Cambridge University have confirmed that the orbits of the six extreme trans-Neptunian objects that served as a reference to announce the existence of Planet Nine are not as stable as originally thought.
NASA’s Cassini spacecraft has been in orbit around Saturn since 2004, studying the giant planet, its rings and its moons. Among the myriad microscopic grains collected by Cassini, a special three dozen stand out from the crowd. Scientists conclude these specks of material came from interstellar space — the space between the stars.