Saturn At Opposition

One of the favorite planets for astronomers (and people in general) to view is Saturn, the large planet with rings. Seeing Saturn in a telescope on a clear night is unforgettable, particularly when you can spot details in the rings, the dark cloud bands currently crossing the planet, and up to 5 or more of the moons that orbit the ringed giant. On June 3, 2016, Saturn will arrive at opposition, providing an excellent opportunity to view the 6th planet in our solar system and the wonders that it has to show.

Saturn is a planet of average brightness, and being that it lies almost 750 million miles from Earth, it doesn’t stand out as well as bright Venus or Jupiter. Fortunately, Saturn is easy to find this year in between the constellations Scorpius and Ophiuchus, as bright Mars is nearby (having gone through its own opposition just a few weeks ago!). Find Mars in the south, then look to the east of Mars. Saturn will be the next brightest golden star to the east of Mars.

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Saturn through a telescope. The Cassini Divide in the rings can be seen near the outer edge. Image taken by me

You can’t see Saturn’s rings without optical aid. Usually, 30x magnification or more will do the trick. Seeing Saturn’s rings for the first time is quite memorable! For the best experience, you should use a telescope if you are able. Any size telescope will do, however the larger the diameter of your telescope, the more likely you will be to catch the many moons of Saturn.

Here are a few things to look for when using a telescope to view Saturn. First, look and see if you can see the rings extended behind the planet. Currently, Saturn is tilted away from Earth near it’s maximum. That allows near optimum viewing of the rings, and you should be able to see the rings behind the north pole of Saturn (which is the pole currently facing Earth).

Second, if the seeing is steady, crank the magnification up to 150x-200x and see if you can spot the Cassini Divide in the rings near the outer edge. The Cassini Divide is a split in the rings, and can be difficult to see at lower magnifications or if the seeing isn’t steady. The fact that Saturn is lower than 30° above the southern horizon for those who live in the mid-northern latitudes doesn’t help, but if you’re lucky, the seeing will clear and you can see the Cassini Divide. If the seeing is very clear, try cranking up the magnification more, to 300x-400x and see if you can spot the elusive Encke Divide, which is a thin split in the ring found between the Cassini Divide and the outer edge of the rings. Seeing details in the rings is breathtaking, and hopefully the atmosphere will calm down enough for you to catch a glimpse!

Using 100-150x, see if you can make out the dark cloud bands on Saturn. If the seeing is good enough, you may be able to see multiple shades from the different clouds that stretch across the gas giant. The more magnification you use, the better details you may notice.

And not to be missed are the moons of Saturn. While not as bright as the moons of Jupiter, you can see upwards of 5 moons or more, depending on how large the diameter of your telescope is. Even in smaller telescopes, you should be able to at least make out Titan and Rhea, which are the two brightest of Saturn’s moons. As with Jupiter’s moons, Saturn’s moons are too far away to distinguish colors or features. However, they’re still amazing to spot!

As Saturn’s moons are fairly interesting, and lesser known to the average person than Jupiter’s moons, let’s have a quick peek at the 5 moons you may be able to see…

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Saturn’s largest moon Titan

Saturn’s largest and brightest moon Titan is the second largest moon in the solar system, and is the farthest point from Earth that humanity has actually landed a probe (the lander Huygens carried by the ESA’s Cassini satellite). Titan is the only moon in the solar system with a significant atmosphere, and the only other body in our solar system that has liquid on its surface.

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Image of Titan’s surface taken by the ESA’s Huygens lander

 Titan’s surface is comprised of mainly water-ice and rock, and contains lakes of liquid methane. Titan’s thick atmosphere also contains methane, ethane, and nitrogen. It is thought that Titan has a methane cycle which is similar to Earth’s water cycle, where the methane evaporates, then condenses and precipitates back to the surface.

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Saturn’s second largest moon Rhea

Rhea is the second largest of Saturn’s moons, and is the 9th largest in the solar system. Rhea is largely made up of ice and rock.

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Saturn’s moon Dione

Dione is very similar to Rhea, but is smaller. Also made up of mainly water ice and rock, Dione features ice cliffs on the side of the moon facing away from Saturn.

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Saturn’s moon Tethys

The moon Tethys is the least dense of all the major moons in the solar system, being made up of mostly water ice and a small portion of rock. The surface of Tethys is very bright by comparison, but as Tethys is small, it’s not as readily seen as Titan or Rhea.

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Saturn’s moon Enceladus

Enceladus is another icy moon, containing more water ice than rock. Evidence has been found that Enceladus may have a saltwater ocean under the ice at its south pole that is over 6 miles deep, which makes Enceladus a future target for finding extraterrestrial microbial life. Enceladus also has erupting cryovolcanoes which help comtribute material to one of Saturn’s outer rings.

With so many interesting features to see, from cloud bands to details in the rings, to multiple moons, viewing Saturn is a must on any amateur astronomer’s list. With Saturn approaching opposition, there’s no better time to view Saturn. We even get some help, as the moon won’t be drowning out some of the dimmer moons of Saturn during this opposition. Whether it’s with your naked eyes, a good pair of binoculars, or with a telescope, be sure to give Saturn a good look over the next few weeks!

Don’t forget to share us with your stargazing friends on Facebook and Twitter!

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