You are here

Lunar Eclipse

September 26, 2015

Earth, Moon, and Sun are about to achieve syzygy — a near-perfect alignment. The full Moon will pass through Earth’s long shadow tomorrow night, creating a total lunar eclipse.

Like any object that’s standing in the sunlight, Earth casts a shadow. At the Moon’s distance from Earth, the dark inner shadow is about three times as wide as the Moon itself.

The Moon’s orbit is tilted a bit with respect to Earth’s orbit around the Sun, though, so most months, the Moon passes above or below the shadow. But two or three times a year, on average, the geometry is just right, so the Moon passes through the shadow — creating an eclipse.

This eclipse begins at 8:07 p.m. Central Time, when the lunar disk first touches the inner shadow, known as the umbra. The Moon will be fully immersed in the shadow a bit more than an hour later. Some sunlight will filter into the shadow, giving the Moon a dark red color.

The Moon will remain in the shadow for about an hour and a quarter. It’ll spend another hour moving out of the shadow, creating a partial eclipse.

The entire eclipse will be visible from the eastern half of the country. From points farther west, the eclipse will already be under way as the Moon rises. Still, most of the country will see all of the total eclipse, when the Moon is fully immersed in the shadow — a bit of cosmic syzygy.

This isn’t just an eclipse, though — it’s a Blood Harvest Super Moon. More about that tomorrow.


Script by Damond Benningfield, Copyright 2015

Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.