GREENVILLE, N.C (WNCT) – If you were looking for last night’s (Friday, February 10, 2017) lunar eclipse, you may have not have noticed much at all. The eclipse was partially visible here in the East, but it may not have been as dramatic as you were hoping. That’s because the eclipse was known as a penumbral eclipse, which is much more subtle than a partial or total lunar eclipse.
An eclipse of the moon can only happen at full moon, when the sun, Earth, and moon line up with the Earth in the middle. Earth’s shadow falls on the moon, creating a lunar eclipse. Lunar eclipses happen anywhere from 2 to 5 times a year and there are three kinds: total, partial, and penumbral.
Total lunar eclipse: The inner part of Earth’s shadow, called the umbra, falls on the moon’s face. At mid-eclipse, the entire moon is in shadow, which may appear blood red.
Partial lunar eclipse: The umbra takes a bite out of only part of the moon. The dark bite grows larger, and then recedes, never reaching the total phase.
Penumbral lunar eclipse: Only the more diffuse outer shadow of Earth falls on the moon’s face. This third kind of lunar eclipse is much more subtle, and much more difficult to observe, than either a total or partial eclipse of the moon. There is never a dark bite taken out of the moon, as in a partial eclipse. The eclipse also never reaches totality. At best, at mid-eclipse, very observant people will notice a dark shading on the moon’s face. Others will look and notice nothing at all.
According to eclipse expert Fred Espenak, about 35% of all eclipses are penumbral. Another 30% are partial eclipses and the final 35% are total eclipses.
Pierce Legeion is a meteorologist and digital journalist for WNCT 9 First Alert Weather.