Explained for children: What is a lunar eclipse?

A lunar eclipse occurs up to five times a year. Then we can observe in the sky how a shadow casts on the moon and almost completely swallows it. An event that we always enjoy watching.

Lunar eclipse simply explained

But what is a lunar eclipse and how does it occur? In principle, it’s very simple: the moon is in our shadow – and as we all know, everything is darker in the shadow.

Our earth revolves around the sun, which casts its light on us and creates a shadow on the sunless side of the earth. As the moon revolves around the earth, it consequently also passes through this shadow. However, that rarely happens.

Because the moon does not revolve exactly around our center, but slightly inclined. So it usually runs through the side of the earth facing away from the sun either above the shadow or below it. But at least twice a year it happens that it passes through our umbra – where it is darkest.

Depending on how the earth is positioned to the sun at the time of the lunar eclipse, we can witness the event. Finally, we can only see a lunar eclipse when it is evening or night.

Total and partial lunar eclipse

Astronomers then speak of a total lunar eclipse when the moon is completely swallowed up by our shadow. Due to the moon’s slightly inclined orbit, it sometimes happens that it only intersects part of our shadow. This phenomenon is known as a partial lunar eclipse because only part of our shadow is visible on the moon.

Incidentally, for our century, astronomers predict that there will not be more than two total lunar eclipses in any year – which is extremely rare for a century.

Why is the moon red during an eclipse?

As the word “lunar eclipse” suggests, the sky becomes dark. The fact that we will be a shadow on the moon also speaks in favor of this. Nevertheless, we can see the “dark” moon even in a total eclipse – because it glows reddish. Why?

Light consists of several colors. The light that the sun casts on us is refracted by our earth and arrives in its individual parts in the shadow. Because it is a so-called long-wave light, the color red is directed directly into the umbra and causes the moon to glow red.

Longest lunar eclipse of the 21st century

On July 27, 2018, the total lunar eclipse is scheduled to last from 9:30 p.m. to 11:14 p.m., making it one hour and 44 minutes long. That’s a minute longer than other lunar eclipses that astronomers know have been or are expected to occur this century. So it’s the longest of the 21st century. According to the calculations, there will only be a longer eclipse on June 9, 2123.

So it pays to stay up late on July 27th. The great thing about a lunar eclipse is that you don’t need special glasses like you do for a solar eclipse.

When is the next lunar eclipse?

If you oversleep the appointment, you simply look at one of the total eclipses that are still to come. Here are all of the ones to be seen over Europe over the next ten years:

• January 21, 2019, start: 5:13 am
• May 16, 2022, start: 4:12 a.m
• March 14, 2025, start: 06:59 am
• September 7, 2025, start: 6:12 p.m
• December 31, 2028, start: 4:53 p.m

One can only hope that the night will remain cloudless. By the way, here we explain how clouds form in the first place.