The Moon in The Solar System

Moon: A moon is a celestial body that has attained enough mass to create its own gravitational field, orbits around the Sun, but is not the dominant body in its area. Some moons are big enough that they can create an orbit around the Sun, however because they were captured by a planet they cannot. This means that the large celestial bodies that orbit the 8 planets are moons. Here is a brief description of four of the most prominent/interesting moons in the solar system:

Ganymede, Jupiter – This is the largest moon in the entire solar system, with a diameter of 5,262 km. This moon is so big that if it wasn’t stuck in orbit around Jupiter it would likely be classified as a planet. It takes 7.1 days for it to complete an orbit around Jupiter. The atmosphere has small amounts of O2 and the surface consists of ice and rock. Titan, Saturn – With a diameter of 5,150 km, Titan is the second largest moon in the solar system. It has an atmosphere with some similarities to Earths, and even has lakes made up of liquified hydrocarbons on its surface. It takes Titan 16 days to complete its orbit around Saturn. Much like Ganymede, Titans surface is made up of ice and rock.

Charon, Pluto – Even though Pluto is no longer considered a planet, it is still the dominant celestial body in its area which means that Charon is a moon. It’s diameter of 1.212 km make it around half the size of Pluto, which means that Pluto and Charon are sometimes referred to as a binary Dwarf system. Charon orbits Pluto every 6.4 days.

The Moon, Earth – To us, the most prominent moon in the entire solar system is our own. The leading theory on its creation is that a large body of rock the size of Mars called Theia impacted the Earth soon after it had been formed. Some of the Earth that was jettisoned in this collision as well as some of Theia came together to form the moon. The moon helps stabilise the wobble that the Earth had due to its tilted orbit. It also uses its gravitational field to create the ides on Earth. The reason why our moon is simply called ‘The Moon’ is because until Galileo Galilei discovered moons orbiting Jupiter, we though our moon was the only moon.