Question

why do lunar and solar eclipses not happen every month?
eclipses only occur during full and new moons.
earth rotates around its axis faster than the moon.
the moon and earth only travel through the penumbras.
the tilt of the moons axis does not allow for monthly alignment.

Explanation:

Eclipses require specific alignments of the Sun, Earth, and Moon. The moon's orbit is tilted about 5 degrees relative to the Earth - Sun plane. This tilt means that the three bodies don't line up perfectly every month. Only during full and new moons when they also align in this 3 - dimensional space do eclipses occur.

Answer:

The tilt of the moon's axis does not allow for monthly alignment.