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ASTROLAB 3D

Eclipse simulator

Move the Moon along its orbit and watch when — and how — an eclipse happens.

Moon's position on its orbit 0°

0° = new Moon (aligned with the Sun), 180° = full Moon (opposite the Sun).

Earth–Moon distance average

Perigee (Moon at its closest) ↔ apogee (at its farthest) — the Moon then appears too small to cover the whole Sun.

Real orbital tilt (5.14°)

This tilt is what explains why there isn't an eclipse at every new and full Moon. Turn it off to see what would happen without it.

Eclipse season (nodes aligned)

The Moon only crosses Earth's orbital plane at two points, the nodes. Enable this option to place a new/full Moon exactly at a node — the only situation where an eclipse can happen despite the tilt.

No eclipse

The Moon isn't aligned with the Sun and Earth right now.

Shadow (umbra) — total eclipse

Penumbra — partial eclipse

The Earth–Moon distance is real; body sizes are enlarged to stay visible on screen.

Drag to orbit the camera · scroll to zoom