Saturn Return!

A little googling has shown me that a “Saturn Return” is some kind of astrological term. I’m sure we don’t want that kind of thing on here. Just to reassure you, I’m not about to get all Mystic Meg on you, I was actually referencing an REM song…

Seriously though, this week I’m focusing on Saturn, the famous ringed planet. It’s just passed opposition so now is a great time to get out there and see what is regarded to be one of the wonders of the solar system. And hurry to see it while you can because from this year until the early 2020’s, Saturn is going to be a difficult planet to see from Northern latitudes as it skirts our horizon in the constellations of Scorpius and Sagittarius…

Saturn, the Ringed Planet - Photo by NASA

The ringed planet is the faintest of the naked eye planets, getting close to magnitude 0 at best. That means that although its fainter than the others (And it’s debatable whether Mercury could be classed as easier to see) it’s still a pretty bright object. At the moment it’s lurking in Libra, so miles from any other bright stars except for Spica, the brightest star in the constellation of Virgo.

Naked Eye

Saturn is most prominent at about Midnight, fairly high and due south. It’s a yellowy star and brighter than anything else around it, but otherwise not immediately interesting.

Image thanks to Stellarium

 

Binoculars

Once you get Saturn in the binoculars you may be disappointed to find that you can’t see the famous ring system. Even very large binoculars will show the planet as an oval at best. You might be able to make out a small orange dot close to Saturn though – this is Titan, its largest moon, and one of the largest in the solar system. Its surface is permanently shrouded in methane clouds that tint it orange, and beneath them lies an ocean of liquid methane.

Telescope

With a telescope Saturn isn’t just interesting, it’s one of the most beautiful objects in the solar system. Even a modest aperture will show you the famous rings. For a long time people didn’t know what the rings were – astronomers even speculated that they were solid objects. They did observe that the rings change their orientation to us over time. At present they’re angled towards us so we see their full extent – at this time with good seeing and enough aperture you can make out the gap between the two main ring systems, the Cassini Division. In about ten years’ time, as the planet wobbles on its axis, the rings will be edge on, appearing as a long line, and for a while they’ll be completely invisible. This is the best time to look for the other moons; Dione, Tethys, Rhea and Enceladus, if your aperture is up to it. You can see them now from time to time, but the rings will obscure them every so often. Probably the other most bizarre moon of Saturn (And it has 53 named moons) is Iapetus, which featured in Arthur C Clarke’s novelisation of 2001: A Space Odyssey* – half of it is highly reflective while the other half is quite dark. When the reflective side is turned towards us it’s easy to see, but at other times it becomes quite hard.

Freaky Iapetus - Photo by NASA/JPL/Space Science Institute

Aside from the impressive ring system, Saturn doesn’t show much more. There is some banding, under clear skies, but mostly it’s the rings that steal the show.

* The location of the final monolith to Iapetus in the book is because it was developed concurrently with the film, but in the later novels Clarke sticks with the film’s location orbiting Jupiter. Conversely the famous line, “Oh my God, it’s full of stars,” only appears in the book, but was used in the film’s sequel 2010.