Question

1. why does the moon not always block the sun to form a solar eclipse during each rotation?

the sun is too far away from the earth
the moon is too far away from the earth
the moons orbit is not in the exact same plane as the sun and earth
the moon is too small to fully cover the sun

Explanation:

A solar eclipse occurs when the Moon passes between the Sun and Earth. For a solar eclipse to happen during every rotation of the Moon (which is about a month), the Moon's orbit would need to be in the exact same plane as the Sun - Earth plane. But the Moon's orbit is inclined at about \(5.145^{\circ}\) to the ecliptic (the plane of Earth's orbit around the Sun). So, most of the time, when the Moon is between the Sun and Earth, it is either above or below the direct line - of - sight from Earth to the Sun.

Answer:

The Moon’s orbit is not in the exact same plane as the Sun and Earth.