Way out in the deep freeze of our solar system lies an unassuming moon quietly circling around Neptune…
…or so you thought.

Did you know that this quiet little moon is the largest moon to have a retrograde orbit (spins opposition to its planet)?  And speaking of large, it’s the 7th largest moon in the solar system.  AND, children, it has a nearly perfect circular orbit.

Thought to be a Kuiper Belt capture, Triton acts a lot like Pluto.  Also, it’s one of the few moons in the Solar System known to be geologically active.  That’s right; volcanos.  You won’t see many impact craters looking at Triton.  Maybe a few, but you’ll probably mistake most of those with volcanos.

Voyager 2 evidence of cryovolcanism

Discovered just 17 days after Neptune itself, William Lassell also thought he saw a ring system around Neptune, but was pretty much laughed out of the astronomical community for that.

Ha.  Ha.

Triton’s retrograde orbit has been the object of study for years.  True, there are smaller moons – much further than their primary – which exhibit retrograde orbits, but none as close or as large as Triton.  As I said, Triton also orbits its primary in a near perfect circle.  That’s very uncommon.  It is believed that in about 3.6 billion years, Triton will either impact Neptune’s atmosphere or cause a ring system to rival Saturn.

Triton has a very thin atmosphere of nitrogen, methane, and carbon monoxide.  It may also have liquid water below the surface due to the tectonic activity… but it’s not considered a candidate for life.

Voyager 2, of course... Neptune

Interested?