How do S-E-M relationships produce lunar phases and eclipses?

Answer 1

S-E-M in this case stands for "Sun - Earth - Moon", and the relationship between the Moon circling the Earth and both of them being illuminated by the Sun explains the phases of the Moon; we're looking at the Moon from HERE, but the sunlight illuminating the Moon is coming from over THERE.

Eclipses can only happen when the Earth and Moon are lined up so precisely that the shadow of one falls on the other. A solar eclipse is where the Moon's shadow touches the Earth; a lunar eclipse is when the Earth's shadow darkens the Moon.

Answer 2

S-E-M relationships, where Earth is in the center surrounded by the Moon, help produce lunar phases as we see different portions of the Moon illuminated by the Sun based on its position relative to Earth. Eclipses occur when the Earth, Moon, and Sun align in a specific way, resulting in a lunar eclipse when Earth moves between the Sun and Moon, and a solar eclipse when the Moon moves between the Sun and Earth.