What is a Lunar Eclipse?During a lunar eclipse, Earth comes between the Sun and the Moon, blocking the sunlight falling on the Moon. There are two kinds of lunar eclipses:A total lunar eclipseoccurs when the Moon and Sun are on opposite sides of Earth.A partial lunar eclipsehappens when only part of Earth's shadow covers the Moon.NASA Lunar Eclipse Guides: 2011-2020and 2021-2030.During some stages of a lunar eclipse, the Moon can appear reddish.This is because the only remaining sunlight reaching the Moon at that point is from around the edges of the Earth, as seen from the Moon's surface. From there, an observer during an eclipse would see all Earth's sunrises and sunsets at once.What Are Lunar Phases?Our Moon doesn't shine, it reflects. Just like daytime here on Earth, sunlight illuminates the Moon.
Credit: NASA/Bill DunfordWe just can't always see it.When sunlight hits off the Moon's far side — the side we can't see without from Earth the aid of a spacecraft — it is called a new Moon.