Solar Eclipse Geometry
This interactive simulator explores Solar Eclipse Geometry in Astronomy & The Sky. Sun–Moon–Earth: angular sizes, umbra and penumbra cones, orbit tilt. Use the controls to change the scenario; watch the visualization and any graphs or readouts to connect the model with lectures, labs, and homework.
Who it's for: Best once you already know the basic definitions and want to build intuition. Typical context: Astronomy & The Sky.
Key terms
- solar
- eclipse
- geometry
- solar eclipse geometry
- astronomy
How it works
A solar eclipse needs the Moon between Earth and the Sun. The umbral cone is where the entire photosphere is blocked; the penumbra is where only part of the Sun is covered. Changing Earth–Moon distance changes whether the umbra reaches the surface (total) or you see a ring (annular).
Key equations
More from Astronomy & The Sky
Other simulators in this category — or see all 22.
Lunar Eclipse Geometry
Sun–Earth–Moon: Earth’s shadow on the Moon; total, partial, and penumbral (schematic colors).
Moon: Tidal Locking
Synchronous rotation: same lunar face toward Earth as it orbits.
Mars Retrograde Loop
Earth overtakes Mars: apparent backward loop among the stars (schematic).
Sidereal vs Solar Day
Why noon returns after slightly more than 360° of rotation (~4 min shorter sidereal day).
Axial Precession
Spin axis slowly cones; ~26 kyr cycle changes the pole star (schematic).
Ecliptic & Zodiac Band
Celestial equator vs ecliptic, obliquity, Sun on the yearly path (symbols as map, not astrology).