Solar and Lunar Eclipses

In a solar eclipse, the Moon passes between the Sun and Earth and casts its shadow on us — the Sun appears to go dark. In a lunar eclipse, Earth passes between the Sun and the Moon, and our planet’s shadow falls on the Moon, often turning it red.

Only during the brief seconds of totality, when the Sun is completely covered — and only then. During every partial phase and every annular eclipse, you must wear certified eclipse glasses. Lunar eclipses are safe to watch with the naked eye at all times.

Both types need the same alignment: the Sun, Earth, and Moon lined up near the nodes where the Moon’s orbit crosses Earth’s orbital plane. A solar eclipse at new Moon is typically followed or preceded by a lunar eclipse at full Moon about two weeks later.

It is the moment the alignment is at its best — the deepest point of a lunar eclipse or the longest totality of a solar one. Eclipse times are usually quoted for this instant.

Somewhere on Earth, roughly every 18 months. But any single spot waits an average of about 375 years between total solar eclipses — which is why travelers chase them around the globe.

The Moon passes only through Earth’s faint outer shadow (the penumbra), so it dims slightly instead of turning red. It is the subtlest kind of lunar eclipse and is easy to miss if you aren’t looking for it.