Key Idea.
Section 1
Physical Blocking vs. Viewing Angle
Unlike moon phases (which are about viewing angles), a Lunar Eclipse is about physical shadows.
Because Earth is a solid object, it casts a long shadow into space. If the Moon travels into this shadow, the supply of sunlight is physically cut off.
Section 2
The Eclipse Alignment
For a lunar eclipse to occur, a precise alignment is required: Sun — Earth — Moon.
Earth must be directly in the middle to cast its shadow on the Moon. This can only happen during a Full Moon phase.
Expand to review the lesson summary and core properties.
Section 1
Physical Blocking vs. Viewing Angle
Unlike moon phases (which are about viewing angles), a Lunar Eclipse is about physical shadows.
Because Earth is a solid object, it casts a long shadow into space. If the Moon travels into this shadow, the supply of sunlight is physically cut off.
Section 2
The Eclipse Alignment
For a lunar eclipse to occur, a precise alignment is required: Sun — Earth — Moon.
Earth must be directly in the middle to cast its shadow on the Moon. This can only happen during a Full Moon phase.