Lunar ECLIPSE

A lunar eclipse occurs when the Moon passes within Earth's umbra (shadow). As the eclipse begins, the Earth's shadow first darkens the Moon slightly. Then, the shadow begins to "cover" part of the Moon, turning it a dark red-brown color (typically - the color can vary based on atmospheric conditions). The Moon appears to be reddish because of Rayleigh scattering (the same effect that causes sunsets to appear reddish) and the refraction of that light by the Earth's atmosphere into its umbra.

1. Select a good place to watch. Yes, you can see it from cities or suburbs, but rural locations add clarity to the night sky, plus the sights and sounds and smells that can make an eclipse experience truly memorable. There’s a special beauty to watching in a country location, where thousands of stars pop into view and where the landscape around you will darken as the eclipse progresses.

If possible, the ideal location would have a wide open view of the sky, unobscured by trees or tall buildings. City parks or state parks are often good places to watch the skies. Check the closing times! Or plan to camp out overnight.

When the eclipse begins, just recline comfortably (lawn chairs are great!) and observe the eclipse.

2. Know the stages of a total lunar eclipse. Eclipses last several hours and have several parts.

Penumbral eclipse begins. The outer, light penumbral shadow begins to cover the moon. It looks like a dusky shading moving across the moon’s face. This phase of the eclipse is subtle. Some people say they can’t tell it’s happening, even while looking right at it. We’ve heard it said you can’t discern the shadow until it reaches across roughly 70 percent across the moon’s face, but, in actuality, discernment is an individual skill. You might or might not see it before then. You might not detect anything until the partial eclipse begins.

Partial eclipse begins. The inner, dark umbral shadow begins to cover the moon. Like the penumbral shadow, it starts on one side and slowly creeps across the moon’s face. It looks like a dark bite taken out of the moon. Earth’s shadow looks completely dark at first. As the eclipse progresses, it’ll begin to take on a reddish-brown color that you can capture in time-exposure photos. Notice that the shadow on the moon’s face is curved. This fact enabled Aristotle to deduce Earth is a sphere, in the 4th century BC. When about three-fourths of moon is covered, the part in shadow should begin to glow dimly, like a burner on an electric stove. Also notice the light surrounding you on Earth. It was a bright moonlit landscape, and the ground may have been cast with dark moon shadows. Now the brightness gradually dims, and the world around you becomes dark, as on a moonless night.

Total eclipse begins. The dark shadow completely covers the moon. This is the total phase of the eclipse, called the totality. During the totality, the shadow on the moon often appears red. It is very beautiful, and the subtle colors change and shift through totality! Plus, red isn’t the only color you’ll see during totality. There are grays and browns, too. Some people say they see a rim of the color turquoise on the moon, in the minutes around the start and end of totality. This turquoise color is the result of absorption by Earth’s ozone layer. The various swaths of color across the moon’s face – especially toward the beginning and ending of totality – create an effect known as the Japanese lantern effect. You can capture it in photos, like the photo above by Monica Hall.

Greatest eclipse. The middle of the eclipse. The totality is at its mid-point. The shadow on the moon might now look reddish, or very dark, depending on whether a major volcanic eruption has recently taken place back on Earth. Volcanic eruptions may add aerosols to Earth’s stratosphere, which can darken an eclipse. Notice that the eclipsed moon looks more three-dimensional than an ordinary full moon. Look deeply within the shadow on the moon’s face. Can you recognize the familiar face of the man in the moon? Sometimes Earth’s shadow hides or obscures the moon’s surface features. Think about what it would be like to be on the moon during the total eclipse. During the totality, an astronaut on the moon would see the sun eclipsed by the Earth. There’d be a sunlit ring around Earth, really the light of all the world’s ongoing sunrises and sunsets. Be aware that, if you were on the moon, you’d experience a sudden and dramatic temperature drop! The moon doesn’t have an atmosphere to retain heat. Before the eclipse, the sunlit side of moon started out about 266 degrees Fahrenheit. Hidden in Earth’s shadow, temperatures on this same part of the moon plunge to about minus 146 degrees Fahrenheit — a drop of over 400 degrees!

Total eclipse ends. The inner, dark umbral shadow begins to leave the moon’s face. A sliver of light appears on one edge of the moon. For the next hour or two, gradually less and less of the moon will be in Earth’s inner, dark umbral shadow.

Partial eclipse ends. The dark umbral shadow leaves the moon.

Penumbral eclipse ends. The light, outer penumbral shadow leaves the moon. The eclipse is over.