Lunar Eclipses

• A Lunar eclipse is an eclipse when the Moon is covered by a shadow.

• These happen when the Earth moves into a direct line between the Sun and the Moon stopping all light from reaching the Moon.

• If it wasn't for the Moon's 5 degree inclination with respect to the Earth-Sun plane, there would be a Lunar eclipse every full moon.
  
  Earth's Umbra

• The shadow that the Earth casts upon the Moon has two regions.
• The main part of the shadow, which is directly in line with the Sun, is called the Umbra.
• This is the point where all light from the Sun is blocked out and a total lunar eclipse is observed.

  Earth's Penumbra

• The other region of shadow is called the Penumbra and this causes a partial eclipse.
• The shadow this casts is not as dark as the Umbra and so only blocks out some of the sunlight.