See Saturn at Its Best for 2013

With its rings tipped nicely into wide view, right now the ringed planet is its closest to Earth — making it a visual treat in telescopes of any size.

Saturn takes over from Jupiter as the starring planet of the evening sky this spring, and right now it's closer, bigger, and brighter than at any time for the rest of the year. The ringed planet comes to opposition on the night of April 27-28, and for the next few weeks it remains essentially the same apparent size: 19″ across at the equator and 42″ across from ring-tip to ring-tip (about a Jupiter-width).

Saturn shines fairly high in the southeast by early evening, below Arcturus and Spica. If you still haven't looked at Saturn in a telescope since last year, the change will be dramatic. The rings now present themselves very invitingly, tilted a wide 17° or 18° from our line of sight, the widest they've appeared since 2006. They will continue to open (with minor seasonal fluctuations) until reaching a maximum of 27° in 2017.

Saturn's main telescopic features are labeled on this fine photograph taken by Robert English on February 7, 2012, with a 20-inch Newtonian reflector. At the time the rings were tilted 15°.
Robert English
The smallest astronomical telescope should reveal the rings easily and, with a little more effort, the dark Cassini Division between the A and B rings. The dusky C ring is more of a challenge to spot where it appears against the dark-sky background, but its dark shading is easier to see where it crosses Saturn's bright face just inside the B ring.

Seeing any further detail in the rings really takes magnification upwards of 200× on a high-quality 8-inch or larger scope. It also takes time and patience. Rare is the night when the atmospheric seeing is steady and sharp enough to let your scope do its best. Moreover, it takes a lot of time gazing into the eyepiece to register everything at the limit of your vision. Very subtle banding in the rings is occasionally detectable under near-perfect conditions.

The Seeliger effect: Christopher Go took these images of Saturn on March 2nd (top) and April 24th. Notice how the rings brightened with respect to the globe. And on the 24th, Saturn was still three days from opposition.
For several night around this week's opposition, watch for the Seeliger effect: a noticeable brightening of the rings with respect to the globe. This is caused by the fact that the solid-ice ring particles "backscatter" sunlight back in the direction it came from more effectively than the planet's cloud tops do.

In the weeks and months after opposition, note the increasingly visible shadow of the planet's globe on the rings. It's the narrow black gap right where the rings pass behind the globe's celestial east (following) side. After opposition, we start seeing a little around the planet's eastern edge compared to the direction of the incoming sunlight.

More to See Than Just Rings

Like Jupiter, Saturn is gas planet showing us banded cloud tops. But Saturn is both smaller and farther than Jupiter, and its markings are more deeply veiled under high-altitude haze. Even so, my 6-inch scope almost always shows some banding: the bright Equatorial Zone, the slightly darker North Equatorial Belt (its southern sibling is behind the rings now), and the dusky North Polar Region. Occasional subtler banding is sometimes detectable in the mid-latitudes. During moments of steady seeing, large scopes often show tinier white spots, which are localized storms. Get other tips from our Saturn observing guide.

Of course, Saturn and its rings are surrounded by extra baubles: more moons for amateur scopes than around any other planet. Even a 60-mm scope will usually reveal appropriately named Titan, a world half again as big as our Moon. A 6-inch will show Titan's orange color: the photochemical smog that makes its thick atmosphere opaque, hiding Titan's rainclouds, rivers, and lakes of liquefied natural gas.

A 4- or 6-inch scope will also show Iapetus, Rhea, Dione, and (with a little difficulty) Tethys. An 8-inch may also get you fainter Enceladus closer in. You can identify the moons, or find exactly where to look for them, at any time and date using S&T.com's Saturn's moons observing aid (requires free site registration) — or, for handy use at your scope, get our new Saturn's moons app for your iPhone.

And of course, take every opportunity to show Saturn to other people! So many amateurs remember a first view of Saturn as the thing that opened to them the riches of astronomy.

2 thoughts on “See Saturn at Its Best for 2013

  1. Paul Cox

    Hi,

    We’ll be broadcasting a free public show on Sunday on the Slooh homepage. We’ll be streaming live images of Saturn from the Canary Islands observatory throughout the show.

    We had a great time on the Partial Lunar Eclipse show last week (with loads of surprises), and this one is bound to be just as fun and informative. Bob Berman will be among the guests.

    The show starts at 6:30PM PDT ¦ 9:30PM EDT ¦ 01:30UTC
    International times are here: goo.gl/nbtul

  2. Azael Barrera

    Excellent article. Also excellent was the explanation by Mr Flanders. Here in Panama, Central America, I was able to follow and video capture Saturn April 28th 9-10:30pm EST until the sky became cloudy and scattered with moon light. We get here this time of the year few day with clear skies. I used a basic Celestron Powerseeker 114mm EQ Newtonian which I use with my students of Introductory Astronomy with a 2x Barlow and an inexpensive Microsoft LifeCam webcam converted -lens removed and fitted in a 1.25" tube- to capture 1000 to 2000 frames each time. After using Registax6 we were able to get nice pictures clearly showing the major rings A, B and C, Cassini’s division, seven zones/belts, the north pole zone. In a more wide view we saw about six moons. It was simply spectacular, and my students were thrilled about how to get these images with a basic telescope.

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