Charon Moon: Curious Facts On Dwarf Planet Pluto's Moon Revealed

Space is a fascinating entity, containing millions of stars, planets and galaxies, spread across such gargantuan distances which we can not even fathom.

To truly explore our solar system, let alone our galaxy, is impossible in our lifetime, and we are unable to guess when we will understand the true size of the universe. Coming back to what we do know, though, the solar system, although barely explored by us, contains the Sun, asteroids, and planets.

There were originally nine planets, but Pluto, a dwarf planet, was officially declassified in 2004, due to its small size it being a part of the outer solar system. Pluto’s moons are named Charon, Styx, Nix, Kerberos, and Hydra. Being almost half the size of Pluto, the Charon Moon, its largest Moon, is so big that Pluto and Charon orbit each other in a binary planet system called the Pluto-Charon system!

It was named after a character in Roman mythology, aka Charon, who helped souls cross the river Acheron to reach Pluto’s underworld. The dwarf planet was discovered in 1938, and 40 years later, Pluto’s biggest moon was found and named Charon Moon in 1978. After reading interesting facts on Charon's surface compositions, cold volcanic activity, and the possible internal water ocean, also check out Europa Moon facts and blood Moon facts. 

Charon Moon Features

Did you know that at one point, it was surmised that Pluto had been destroyed? In 1966, a fictional novel was written which thought that the planet was gone due to an interstellar aircraft!

First discovered in 1978 by astronomer James Christy, Charon had high-resolution pictures taken of it at NOFS. Photographic plates were used to take highly magnified images, which were confirmed on plates dating back to 1965. It was also observed that it was a synchronous orbit, hence confirming that it was real.

A five-year period of the dwarf planet’s and Charon's mutual eclipses and transits erased any doubts about Charon's orbit or existence. The Horizons spacecraft flew over the surface of the dwarf planet, at the distance of 7767.1 mi (12,500 km), in 2005. Out of Pluto’s moons, Charon was observed as well as Pluto during the Horizons Mission. Water crystals have been seen on the surface, as well as a large dark area dubbed Mordor in the north polar region.

Charon Moon Surface Area

The surface of Charon is made of water ice and is not like Pluto’s surface. There is a suggestion that geysers and cryovolcanoes exist on the surface.

The temperature reaches -432 F (-222.2 C), and there are phenomena that are thought to happen due to the condensation of gases. There is more evidence of past geology that suggests an internal ocean frozen up.

This is due to a massive resurfacing event and caused the southern hemisphere to have lesser craters and be smoother than the northern hemisphere. Astronomer James Christy, although not involved in the New Horizons team, had already seen several craters on the surface. One of them has been named Revati after an ancient god in Hindu mythology.

The surface composition of Charon is frigid, and is covered with methane and nitrogen ice, plus water ice. It is believed that it has a small, rocky core. It is also thought that Charon cracking open happened, as the entire Moon has a split like the Grand Canyon. A very plain area on the surface of Charon was given the name Vulcan Planum, which was discovered by the New Horizons spacecraft.

Charon Moon Orbital Period

Did you know that when Charon was originally discovered, it was not known that it is a part of the Pluto-Charon system? Charon has no significant atmosphere, reflecting its rocky, icy interior. The entirety of Charon is also covered in a reddish hue that escaped Pluto's atmosphere.

They are so in sync, relatively, that both of them rotate on their axis every 6.4 days so Charon always shows the same side to Pluto, never rising or setting, causing a phenomenon called tidal locking. The Pluto-Charon system is the only double orbital system that we know of.

Pluto’s rotation and Charon’s happen simultaneously, and Charon has to orbit Pluto every 6.4 days. Compared with planets and moons that we know, the Pluto-Charon system is tipped to the side, and Pluto's rotation is retrograde, that is, it rotates backward.

Charon Moon Distance From Earth

A fascinating fact is that the average distance of Pluto from the Earth is a whopping 3.3 billion mi (5.3 billion km), whereas the distance of Charon from Pluto is only 7,580.7 mi (12,200 km)!

Out of all the moons of Pluto, Charon is the closest one to it. When the New Horizons team explored it - and even Christy noticed this - because Charon is half the size of Pluto, it can act as a mini-planet and can affect Pluto's orbit. The New Horizons team also estimated the time it took to get to Pluto, which was around 10 years of continuous travel and brief hibernation periods, and observation of Pluto Moons gave us significant insight and knowledge that we know today.

What Charon has in common with our Moon or the Earth’s Moon is that the mass is approximately the same, with the same average density. It is estimated that it formed due to a giant impact. A fun fact: when Charon was discovered, Christy noticed a weird elongation when he was viewing Pluto, and hence Charon was discovered!

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for Charon Moon then why not take a look at 25 interesting 2NE1 facts for K-pop music video lovers or 33 mind-blowing '50s fashion facts.