Australasian Science: Australia's authority on science since 1938

It’s Raining on Saturn

By David Reneke

David Reneke’s wrap-up of space and astronomy news.

David Reneke is an astronomy lecturer and teacher, a feature writer for major Australian newspapers and magazines, and a science correspondent for ABC and commercial radio. Subscribe to David’s free Astro-Space newsletter at www.davidreneke.com

The full text of this article can be purchased from Informit.

It seems crazy to talk about rain on Saturn, but it turns out to be true. Saturn’s rings give off a form of rain that falls onto the planet below, covering larger areas than previously thought.

Based on NASA-funded observations and analysis led by the University of Leicester, a new study has found that the rain affects the make-up and temperature structure of parts of Saturn’s upper atmosphere. “Saturn is the first planet to show significant interaction between its atmosphere and ring system,” said James O’Donoghue, a postgraduate researcher at Leicester and lead author of a paper in Nature.

In effect, the rain’s main effect is to reduce the number of electrons in a given space in Saturn’s upper atmosphere. This explains why those electron levels are unusually low at some latitudes. The work also helps us understand the development of the ring system and changes in Saturn’s atmosphere.

“It turns out that a major driver of Saturn’s ionospheric environment and climate across vast reaches of the planet are ring particles located some 60,000 kilometres overhead,” explained Kevin Baines of NASA’s Jet Propulsion Laboratory. “The ring particles affect both what species of particles are in this part of the atmosphere and where it is warm or cool.”

In the early 1980s, images from NASA’s Voyager spacecraft showed several dark bands on Saturn. Scientists...

The full text of this article can be purchased from Informit.