Moons, or "natural satellites", are astronomical objects which orbit a "primary", which can be a planet or other smaller body.


The Moon (Earth)

  • Earth’s only natural satellite.
  • Quarter of the diameter of the Earth.
  • Fifth largest satelilite in the Solar System.
  • Second densest moon in the Solar System, after Jupiter’s Io.
  • The Moon is in synchronous rotation with the Earth, which means that it is always showing the same face towards the Earth.
  • The Moon’s gravitational pull produces the Earth’s tides.
  • The Moon currently orbits at a distance of 30 Earth diameters away from the Earth.

Titan (Saturn)

  • Saturn’s largest moon.
  • The Solar System’s only natural satellite to have a dense atmosphere.
  • Apart from Earth, Titan is the only other object to have stable body of surface liquid.
  • Second largest moon in the Solar System.
  • Larger by volume than Mercury but only half as massive.
  • Primarily composed of water ice and rock.
  • Atmosphere mostly composed of nitrogen.
  • Titan’s wind and rain create a similar surface of dunes, valleys and seas.
  • Titan could possibly be the host of prebiotic organic chemistry or even microbial life.

Io (Jupiter)

  • Densest moon in the Solar System.
  • Innermost of Jupiter’s moons.
  • Named after one of the lovers of Zeus.
  • Volcanically active.

Europa (Jupiter)**

  • Slightly smaller than Earth’s Moon.
  • Atmosphere primarily composed of oxygen.
  • Surface covered with ice.
  • Discovered in 1610 by Gallileo.

Ganymede (Jupiter)

  • Largest and has most mass satellite in the Solar System.
  • Larger than the planet Mercury.
  • Composed of rock and ice.
  • There may be a saltwater ocean beneath the ice.