Eclipses occur when the light from one celestial body, usually a star, is blocked from view by another celestial body, usually a planet or a moon. On Earth, an eclipse occurs when the moon moves into alignment with the sun and Earth, either undergoing a lunar eclipse or causing a solar eclipse. A total eclipse occurs when the shadow from the body blocking the light, known as the umbra, completely covers the source of light; a partial eclipse occurs when the partial shadow, known as the penumbra, blocks the source of light.
A total lunar eclipse occurs when the Earth blocks the light of the sun from the full moon as it passes through the shadow. When this occurs, the sun is on the direct opposite side of the Earth from the moon. A lunar eclipse turns the moon a characteristic copper-red color and can last for up to an hour.
During a solar eclipse, the sun is either partially or completely covered by the moon as it falls into alignment with the Earth and the moon. At this point, both the sun and the moon are both on the same side of the Earth. A total solar eclipse causes the sun to be blocked and only the outer ring, known as the corona, is visible.
It is more common to experience a total lunar eclipse than it is to experience a total solar eclipse. Total eclipses do not occur every month because the moon's orbit is tilted in a way that causes it to often fall above or below the line between the sun and the Earth. A total solar eclipse is much less common to experience because the area in which the total eclipse occurs is roughly 200 miles wide and frequently falls on remote areas of the Earth. In comparison, lunar eclipses are much more common to experience because the eclipsed moon can be seen from any point on the Earth that is under nighttime conditions during the eclipse.