Question

Why don't we have eclipses every month?

Answer 1

Eclipses happen when Earth, Moon and Sun comes in a straight line.

Explanation:

The lunar orbit around Earth is tilted 5.8 degrees to ecliptic apparent path of Sun. Moon goes round the Earth once in 27 days 8 hours. But full moon to full moon is 29.5 days.

Eclipses happen only at the point of intersection of both these orbits called nodes.