Eclipse Apprentice Training

We know that Earth orbits the Sun and the Moon orbits Earth. It takes Earth 365 days, or one year, to orbit the Sun.  It takes the Moon 27 days to orbit Earth. If the Earth’s orbit and the Moons’ orbit were both on flat ecliptic planes, we would be able to see solar eclipses every month, or once every 27 days.  However, the Moon’s orbit is inclined.  It is inclined at an angle of about 5 degrees.  As the Moon orbits the Earth, sometimes it is above the ecliptic plane and sometimes it is below.  Because the Moon’s orbit is inclined, the shadow cast by the Moon often misses the Earth and the shadow cast by the Earth misses the Moon. Every 18 months or so the two orbits line up and we are able to see an eclipse somewhere on Earth.

Ecliptic plane – the imaginary plane of Earth’s orbit around the Sun

Orbit – to go around a star, planet, or moon

Shadow –  darkness caused by the blocking of a light source

Solar eclipse – when the moon passes in between the Earth and the Sun and the Sun’s light is partially or totally blocked by the Moon.

Write, draw, or verbally discuss answers to the following question:

Why don’t we have solar eclipses every month?