Key Idea.
Section 1
The Rareness of Eclipses
If a Full Moon happens every month, why don't we have a lunar eclipse every month?
The answer relates back to Scale. Earth's shadow is a narrow target far out in space. For the Moon to hit this target, the Sun, Earth, and Moon must form a perfect straight line.
Section 2
The Missing Variable
Most of the time during a Full Moon, the alignment is imperfect. From a "top-down" view, they look aligned, but from a "side" view, they are not.
This implies there is a vertical difference in the system preventing the shadow from hitting the Moon every month.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter
Expand to review the lesson summary and core properties.
Section 1
The Rareness of Eclipses
If a Full Moon happens every month, why don't we have a lunar eclipse every month?
The answer relates back to Scale. Earth's shadow is a narrow target far out in space. For the Moon to hit this target, the Sun, Earth, and Moon must form a perfect straight line.
Section 2
The Missing Variable
Most of the time during a Full Moon, the alignment is imperfect. From a "top-down" view, they look aligned, but from a "side" view, they are not.
This implies there is a vertical difference in the system preventing the shadow from hitting the Moon every month.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter