Experiment

Lunar Eclipse Shadow Check

During a lunar eclipse, does Earth's shadow stay round on the Moon the way a spherical Earth predicts?

Materials Needed

Watch the Moon as Earth's shadow moves across it during a lunar eclipse.
Record the curved edge of the shadow at several points in the event.
Compare whether the shadow edge keeps the same rounded character as the geometry changes.

A sphere casts a circular shadow in every orientation. During a lunar eclipse, Earth should project a consistently curved shadow edge onto the Moon.

This visual shows the core geometry the experiment is testing before the real-world observation is made.

The advancing shadow edge appears rounded rather than wedge-shaped or irregular.
That curved edge remains consistent throughout the eclipse sequence.
The event also lines up naturally with full-moon geometry.

A repeatedly circular eclipse shadow is one of the classic geometric signatures of a spherical Earth.

During a lunar eclipse, does Earth's shadow stay round on the Moon the way a spherical Earth predicts?

The experiment’s stated geometry or physical model with fixed inputs across comparisons.

A sphere casts a circular shadow in every orientation. During a lunar eclipse, Earth should project a consistently curved shadow edge onto the Moon.

2026-03-23

The protocol holds location, height, and distance inputs fixed while comparing observation to prediction.
A single ambiguous photo is not enough; repeatable measurements matter.
Primary-source references carry more weight than generic summaries.

A page-specific source set has not been attached yet.

A repeatable observation that matched the competing model better than this experiment’s stated prediction would count against this page.