Why does the moon turn red during a total lunar eclipse?

20 15 On September 27th, NASA photographer Aubrey Geminani took this amazing photo of the perigee total lunar eclipse in Washington State. (NASA/Gemini Aubrey) A rare moon host will usher in the shadow of the early (early) Wednesday (65438+1October 3 1) and the full moon (a super moon because the satellite is close to the earth) passing through the earth. In the so-called super blue blood eclipse, the moon will turn brick red.

The light of the moon is the most striking of the three eclipses (the other two are called polarized light and penumbra). Besides, perfection is necessary: a total lunar eclipse will only happen when the sun, the earth and the moon are perfectly arranged together. In fact, this combination of super moon, blue moon and total solar eclipse has not happened for over 150 years.

When the moon tiptoed to the outside of the earth's shadow and was completely bathed in the darkest part of the shadow, why didn't the lights in the sky be turned off? Why is the moon swallowed by light orange and turned into blood-red light?

The reason is as follows: Imagine you are standing on the moon (with a lot of dust and craters under your feet) and looking down at the earth in the spectacular night sky activities. When the earth is in front of the sun-blocking the sun from shining on the moon-you will see a hot edge around the earth. [data map: total lunar eclipse]

"The dark earth disk is surrounded by every sunrise and sunset in the world at the same time," NASA said. Although our planet is much bigger than the sun, the light of our star bends at the edge of the earth. This light is reflected to the moon.

But until it passes through our atmosphere, it filters out short-wavelength blue light, leaving the red and orange on the surface of the moon unscathed. Look, a red moon.

At different stages of the total lunar eclipse, the moon will have different color changes, from the initial gray to orange and amber. Atmospheric conditions can also affect the brightness of colors. For example, according to NASA, extra particles in the atmosphere, such as wildfires or ashes from recent volcanic eruptions, may cause the moon to have a dark red shadow. [Eclipse: What are they? When is the next time? ]

The moon is not always completely hidden behind the shadow of the earth. During the partial eclipse of the moon, the arrangement of the sun, the earth and the moon was slightly deviated, so the shadow of our planet only swallowed up part of the moon.

A beginner of astronomical phenomenon may not even notice the third kind of eclipse, that is, the penumbral eclipse. The moon is located in the penumbra of the earth, or its faint external shadow.

Wednesday's total lunar eclipse is expected to be seen in Asia, Australia, the Pacific Ocean and western North America.

As for other types of eclipses, the next three penumbral eclipses will occur on June 65438+ 10/June 1, July 4-5 and June 65438+1October 29-30, 2020. According to the time and date, the next total lunar eclipse is expected to be on July 27-28, 20 18, which can be seen in most parts of Australia, Asia, Africa, Europe and South America.

Editor's Note: This article first appeared on 20 16 and was updated on 20 18 Super Blue Blood Eclipse.

Original articles on life sciences.