Solar & Lunar Eclipse Simulator
Eclipses are pure geometry: three bodies in a straight line. Tilt the Moon's orbit and slide it around Earth until the shadows connect — then switch between the solar and lunar view.
Total eclipse
Eclipses need near-perfect alignment
How it works
A solar eclipse happens when the Moon passes between the Sun and Earth, dropping its small shadow onto our planet.
A lunar eclipse happens when Earth passes between the Sun and Moon, and our much larger shadow swallows the Moon.
Because the Moon's orbit is tilted about 5 degrees, the three bodies only line up a few times a year. Reduce the tilt and you can make eclipses happen every single month.
Fun facts
Totality during a solar eclipse lasts at most about 7.5 minutes.
The Moon is 400 times smaller than the Sun but also 400 times closer — which is why they appear the same size.
During a lunar eclipse the Moon turns red from sunlight bent through Earth's atmosphere.
Any given spot on Earth sees a total solar eclipse roughly once every 375 years.
