What is A Lunar Eclipse?

July 12, 2023

Letîcia Alves da Silva

12th Grade

Colégio Militar do Rio de Janeiro

A lunar eclipse occurs when the Earth is positioned between the moon and the sun, causing a precise alignment of the shadow of Earth with the lunar surface, darkening it. Depending on the type of eclipse, it can occur twice a year or every two or three years. It is noteworthy that such a phenomenon only happens during the full moon phase. In general, there are three types of lunar eclipses.

Researchers recorded a temperature drop in two locations where Apollo 12 - the second US spacecraft to land on the moon - had landed. In a period between ten and thirty minutes, the temperature varied from 75.7 C to -102.1 C. The same occurs during lunar eclipses. The satellite's temperature drops dramatically when the Earth’s shadow sweeps the moon—even causing some lunar rocks to disintegrate and gasses to escape from inside the Moon. 

It is important to note that the reason eclipses do not occur every month is that the moon’s orbit is inclined at approximately 5º relative to Earth’s orbit (ecliptic). Thus, an eclipse happens only when the sun and the moon are in the line of intersection of the moon’s orbit with the ecliptic.