Charon: The Mysterious Moon of Pluto

Pluto, once considered the outermost planet of our solar system, is now classified as a dwarf planet. But what many people don’t know is that Pluto has not one, but five moons! The largest and most fascinating of these moons is Charon (moon).

Charon was discovered in 1978 by astronomers James Christy and Robert Harrington during their observations aimed at refining Pluto’s orbit. But what exactly is Charon, and what secrets does this giant moon hold? Let’s take a deeper dive into everything we know about Charon so far.

Basic Facts About Charon

– Charon is approximately 1,214 kilometers (754 miles) in diameter, making it over half the size of Pluto. This means Charon is the largest moon in the solar system relative to its parent body.

– Charon and Pluto are gravitationally locked to one another. This means the same side of Charon always faces Pluto, and vice versa.

– Charon orbits Pluto every 6.387 Earth days. Together with Pluto, their rotation period is also 6.387 days.

– Due to its large size compared to Pluto, some scientists refer to the Pluto-Charon system as a double dwarf planet.

– Charon was formed at the same time as Pluto over 4 billion years ago from a collision between Pluto and a smaller Kuiper belt object.

Is Charon a Dwarf Planet?

As the second largest object in the Pluto system after Pluto itself, some scientists have proposed that Charon could be classified as its own dwarf planet.

Charon clearly orbits the sun rather than Pluto. It is large enough to be round in shape. But a key part of being a dwarf planet is that the object must have cleared its orbit of other smaller objects.

Since Charon and Pluto are gravitationally locked together and share their orbital space, Charon has not cleared other objects from its orbit. For this reason, Charon is still classified as Pluto’s largest moon rather than its own separate dwarf planet.

The Unique Surface of Charon

When NASA’s New Horizons spacecraft flew by the Pluto system in 2015, it revealed Charon has a surprisingly diverse landscape. Near the north pole, a prominent red cap of unknown material stood out against Charon’s generally gray and brown colors elsewhere.

Scientists believe the reddish material is tholins, complex organic compounds formed when methane and nitrogen ice on Charon’s surface are interacted with solar radiation or cosmic rays over billions of years.

Charon also has a network of cliffs and canyons that stretch for hundreds of miles in length. The largest canyon, known as Serenity Chasma, is over 6 miles deep and spans more than 1000 miles wide – almost as large as the Grand Canyon here on Earth!

Like much of Pluto, Charon’s surface is heavily cratered from ancient asteroid and comet impacts. But puzzlingly, there are relatively few small impact craters. This suggests Charon has had some sort of resurfacing event that erased many of the small, old craters from its early history.

The Complex Pluto-Charon System

As the largest moon to its planet in the whole solar system, Charon plays a big role in Pluto’s evolution and potentially habitability. Thermal heat from Pluto and Charon’s gravitational interactions over billions of years have helped maintain subsurface oceans on Pluto.

Charon’s orbital resonance with Pluto also contributes to the strange axial tilt of the Pluto system, which is unlike any other planet. Pluto rotates in the opposite direction of most planets, completing one rotation every 6.387 Earth days.

Scientists are working to untangle how Charon came to be the unusual moon it is today. Future missions may reveal even more mysteries hidden among Charon’s exotic landscape and the unique Pluto-Charon binary system. With its large size and potentially ocean-forming role, Charon is one celestial object that certainly deserves our continued study and fascination.

I hope this blog post provided some new insights about Charon – the mysterious yet important moon of the dwarf planet Pluto. Please let me know if you have any question! I enjoy sharing my passion for space and science.