Categories: Astronomy

Largest Moon of Saturn

The largest moon of Saturn is Titan, measuring 5,150 km across. In fact, Titan is the second largest moon in the Solar System, after Jupiter’s Ganymede. Titan is so big that it’s even larger than planet Mercury, which is only 4,879 km across. And it’s much bigger than the Earth’s moon at 3,474 km.

Astronomers used to think that Titan was actually the largest moon in the Solar System, but when NASA’s Voyager spacecraft first arrived at the moon in the 1980s, they were able to make detailed observations of the moon at its atmosphere. They proved that Titan’s atmosphere extended out for dozens of kilometers, and so the physical moon itself was actually smaller than previously thought, making it smaller than Ganymede.

Titan orbits Saturn at an average distance of 1,221,870 km, completing an orbit every 15.945 days. It’s tidally locked to Saturn, so it always presents the same face to Saturn. So a day on Saturn is also the same amount of time it takes to orbit Saturn.

Titan is the only moon in the Solar System known to have a thick atmosphere. In fact, the pressure of the atmosphere on the surface of Saturn is 1.5 times greater than the atmospheric pressure here on Earth. Of course, the atmosphere of Titan is almost entirely nitrogen, and the temperature is -179° C. So it wouldn’t be a comfortable place to visit without a spacesuit.

We’ve written many articles about Titan for Universe Today. Here’s an article about seasonal changes on Titan, and here’s an article about how Titan’s haze acts like an ozone layer.

If you’d like more info on Titan, check out Hubblesite’s News Releases about Saturn. And here’s a link to the homepage of NASA’s Cassini spacecraft, which is orbiting Saturn.

We’ve also recorded an episode of Astronomy Cast just about Saturn’s moons. Listen here, Episode 61: Saturn’s Moons.

Fraser Cain

Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay. Here's a link to my Mastodon account.

Recent Posts

The First Close-Up Picture of Star Outside the Milky Way

Like a performer preparing for their big finale, a distant star is shedding its outer…

11 hours ago

Here’s What We Know About Earth’s Temporary Mini-Moon

For a little over a month now, the Earth has been joined by a new…

12 hours ago

New Study Suggests Black Holes Get their “Hair” from their Mothers

Despite decades of study, black holes are still one of the most puzzling objects in…

13 hours ago

Gaze at New Pictures of the Sun from Solar Orbiter

74 million kilometres is a huge distance from which to observe something. But 74 million…

13 hours ago

Are Fast Radio Bursts Caused by Interstellar Objects Crashing Into Neutron Stars?

Astronomers have only been aware of fast radio bursts for about two decades. These are…

18 hours ago

Here’s How to Weigh Gigantic Filaments of Dark Matter

How do you weigh one of the largest objects in the entire universe? Very carefully,…

20 hours ago