When a body passes in front of another, occulting the light from it

Solar Eclipses

The Moon passes between the Sun and the Earth cutting out the sun's light.

  1. During a Partial Eclipse only part of the sun's light is cut out and the sun appears like a crescent to viewers on Earth.
  2. During a Total Eclipse the moon totally blocks out the sun and the part of the Earth in its path becomes dark.
  3. During an Annular Eclipse the moon goes right in front of the sun as in a total eclipse but is too small to block out all of the sun's light so the sun appreas like a ring round the moon.

Lunar Eclipses

The Earth passes between the sun and the moon. The moon shines by reflected sunlight so when the Earth prevents the sunlight reaching the moon the moon shines less.

  1. During a partial lunar eclipse only part of the moon is in line from the sun and the Earth so only part of the moon is dark.
  2. During a total lunar eclipse the Earth blocks out sunlight from the whole of the moon but the moon is still visible from Earth because some sunlight is defracted through the Earth's atmosphere and reaches the moon.