That's a great question! It's true that Charon is almost as big as Pluto, but it's not quite there.

Here's the breakdown:

* Pluto's diameter: 2,376.6 kilometers (1,476.8 miles)

* Charon's diameter: 1,212 kilometers (753 miles)

Charon is significantly smaller than Pluto, making up about half of Pluto's diameter.

However, it's still a remarkably large moon compared to other moons in the solar system. In fact, the Pluto-Charon system is often described as a double planet or a binary system because of their relative sizes and the fact that they both orbit a common center of gravity.