Saturn tagged posts

This view looks toward the sunlit side of the rings from about 1 degree above the ring plane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Nov. 23, 2015. The view was acquired at a distance of approximately 28,000 miles (44,000 kilometers) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 54 degrees. Image scale is 1.8 miles (3 kilometers) per pixel. Image Credit: NASA/JPL-Caltech/Space Science

Their contrasts are related, in large part, to their sizes. Tethys (660 miles across) is large enough to be spherical and to have varied geology, like chasms and smooth plains, along with some puzzling arc-shaped features (see PIA19637 http://photojournal.jpl.nasa.gov/catalog/PIA19637) ...

A false-color composite image, constructed from data obtained by NASA’s Cassini spacecraft showing the glow the aurora about 1,000 km above the cloud tops of Saturn’s south pole (credit NASA/JPL/University of Arizona/ University of Leicester)

The evidence that Saturn’s upper atmosphere may, when buffeted by the solar wind, emit the same total amount of mass per second into its magnetosphere as its moon, Enceladus, has been found by UCL scientists working on the Cassini mission. Magnetospheres are regions of space that are heavily influenced by the magnetic field of a nearby planet and can contain charged particles in the form of plasma from both external and internal sources.

In the case of Saturn, its moon Enceladus ejects water from its icy plumes which is ionised into H2O+, O+, OH+ ...

Artist’s impression of a fifth giant planet being ejected from the solar system. Image credit: Southwest Research Institute

The existence of a 5th giant gas planet at the time of the Solar System’s formation – in addition to Jupiter, Saturn, Uranus and Neptune that we know of today – was first proposed in 2011. But if it did exist, how did it get pushed out? For years, scientists have suspected the ouster was either Saturn or Jupiter.

“Our evidence points to Jupiter,” said Ryan Cloutier
Planet ejections occur as a result of a close planetary encounter in which one of the objects accelerates so much that it breaks free from the massive gravitational pull of the Sun...