Saturn’s Moons – A Few Great Places to Visit

This image of Saturn and four of its moons was taken by the author on April 12, 2012 from EPA’s Edison, New Jersey facility. The moons are (from left to right): Titan, Dione, Tethys and Rhea.

By Jim Haklar

As an EPA employee, I’m reminded every day how fragile our environment is.  But when I take my telescope outside on a clear, calm night and point it skyward, I can see a place that may have environments that are just as special as our own.  And this place is Saturn.  You’ve heard of Saturn – the planet with the rings.  While most people think the rings are what makes Saturn unique (and they really are unique, being less than 1 mile thick but up to 175,000 miles across), to me it’s Saturn’s moons that make it a really special place.

Saturn has over 60 moons, 53 of which have names.  The names typically come from Greek mythology, and most of the moons are named after Saturn’s brothers, the Titans, and Saturn’s sisters, the Titanesses.  In mythology, these were giants who ruled before being conquered by Jupiter.

A while back I took a picture of Saturn with four of its moons: Titan, Dione, Tethys, and Rhea.

Titan is considered to be the most Earth-like world that has been discovered (it’s actually a frozen version of how Earth looked like billions of years ago).  Titan is the second largest moon in the solar system and has rivers and lakes made up of chemicals like ethane and methane.   Imagine being stuck in a “rain” storm on Titan!

Dione has a lot of craters (just like on our Moon) but it also has bright walls of ice that form canyons.   A very fine powder of ice from one of Saturn’s rings constantly rains down on Dione.

Rhea is a small (about 950 miles in diameter) , cold moon with no atmosphere that is similar to Dione. It has been described as a frozen dirty snowball!

Tethys is also small (less than 700 miles in diameter) and it is closer to Saturn than our Moon is to the Earth.  It is made up of mostly water ice with a little bit of rock.  It has two huge features; a giant crater called Odysseus and a valley called Ithaca Chasma.

Right now Saturn is visible, for most of the night, in the constellation of Virgo.  Take a few minutes and look up at the night sky, and think about all the strange environments that are waiting to be explored.

About the Author: Jim is an Environmental Engineer out of EPA’s Edison, New Jersey facility, where he manages PCB cleanups.  On clear nights he can frequently be seen with his telescope spying on our planetary neighbors.

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