Observations by the James Webb Space Telescope are giving scientists a fuller understanding about the composition and evolution of Pluto's moon Charon, the largest moon orbiting any of our solar system's dwarf planets.

Webb, for the first time, detected carbon dioxide and hydrogen peroxide -- both frozen as solids -- on the surface of Charon, a spherical body about 750 miles (1,200 km) in diameter, researchers said on Tuesday. Those are added to the water ice, ammonia-bearing compounds and organic materials previously documented on Charon's surface.

Charon, discovered in 1978, has the distinction of being the solar system's largest moon relative in size to the planet it orbits. It is about half the diameter and an eighth the mass of Pluto, a dwarf planet that resides in a frigid region of the outer Solar System called the Kuiper Belt, beyond the most distant planet Neptune.

The distance between Charon and Pluto is about 12,200 miles (19,640 km), compared to the 238,855 miles (384,400 km) on average separating Earth from its moon.