How Solar Eclipses Work

A solar eclipse is when the moon passes between the Earth and the sun. The moon's shadow falls on the Earth's surface and blocks out the sun's light as we see it from the Earth.

The moon crosses the Earth's orbital plane only twice a year because the moon orbits the Earth at an angle. For an eclipse to take place, the moon must be in the correct phase. For a solar eclipse, it must be a new moon.

There are three types of solar eclipses:

• Total - the entire central portion of the sun is blocked out.
• Partial - only a part of the sun's surface is blocked out.
• Annular - only a small, ring-like sliver of light is seen from the sun's disc.

The moon's shadow has a central region (umbra) and an outer region (penumbra). If the umbra passes over you, the entire central portion of the sun will be blocked out, and you will see a total solar eclipse. If the penumbra passes over you, you will see a partial solar eclipse.