During a lunar eclipse, the Earth moves directly between the Sun and the Moon, casting its shadow across the Moon and making it darken and often turn red.

Quick Scoop: What actually happens?

  • The Moon is full and the Sun, Earth, and Moon line up in (almost) a straight line.
  • Earth’s shadow stretches out into space and the Moon travels through that shadow.
  • Direct sunlight is blocked, so the Moon fades, darkens, and often glows coppery red instead of disappearing.

Think of it like this: you’re shining a flashlight (the Sun) on a ball (the Moon), then you move your head (the Earth) right in front—the ball ends up in your shadow.

The stages of a lunar eclipse

A total lunar eclipse unfolds in clear steps.

  1. Penumbral eclipse begins
    • The Moon enters the pale outer part of Earth’s shadow (penumbra).
    • The dimming is very subtle; many people barely notice anything at first.
  1. Partial eclipse begins
    • The Moon starts sliding into the dark inner shadow (umbra).
    • You see a dark “bite” or curved shadow creeping across the Moon’s disk.
  1. Total eclipse (totality) begins
    • The Moon is now fully inside the umbra.
    • It stops looking bright white and instead glows red, brown, or deep orange.
  1. Maximum eclipse
    • This is the deepest point of the eclipse, when the Moon is most strongly darkened and colored.
  1. Total eclipse ends → Partial ends → Penumbral ends
    • The Moon gradually moves out of the umbra, then the penumbra, reversing the steps.
    • It brightens back to a normal full Moon.

Why the Moon turns red (the “Blood Moon” effect)

  • During totality, Earth blocks direct sunlight from reaching the Moon.
  • But some sunlight skims through Earth’s atmosphere, bends (refracts), and still reaches the Moon.
  • Earth’s atmosphere scatters away most of the bluer light (Rayleigh scattering), letting the longer, redder wavelengths pass through.
  • That red light is projected onto the Moon, so we see it glowing red or copper—this is why people call it a “Blood Moon.”

The exact color depends on how dusty, smoky, or cloudy Earth’s atmosphere is at that time: more particles can make the Moon look darker and deeper red.

Types of lunar eclipses

[3][7] [5][3] [7][9][3] [3][5] [1][9][7][3] [9][1][3]
Type What happens What you see
Penumbral lunar eclipse Moon passes only through Earth’s outer shadow (penumbra).Very slight dimming; often hard to notice with the naked eye.
Partial lunar eclipse Part of the Moon enters the dark inner shadow (umbra).A dark curved “bite” is taken out of the Moon’s disk.
Total lunar eclipse The entire Moon passes through the umbra.Moon turns red, brown, or orange (a “Blood Moon”).

Extra cool facts and context

  • A lunar eclipse can only happen at Full Moon , but not every Full Moon gives an eclipse because the Moon’s orbit is tilted, so the alignment has to be just right.
  • Unlike a solar eclipse, it’s completely safe to watch a lunar eclipse with your naked eyes, binoculars, or a telescope.
  • People across the entire night side of Earth can usually see a lunar eclipse if the Moon is above their horizon.
  • Recent eclipses often become trending “sky events,” with people sharing photos and time-lapse videos whenever a striking red Moon appears.

TL;DR: During a lunar eclipse, Earth lines up between the Sun and the Moon so that Earth’s shadow falls on the Moon; the Moon darkens and often turns red because sunlight filtered through Earth’s atmosphere softly illuminates it.

Information gathered from public forums or data available on the internet and portrayed here.