The first lunar eclipse of 2021 is going to happen on May 26. This is going to be a super lunar event, as it will be a supermoon, a lunar eclipse and a red blood moon all at once. Here’s how and why it happens.
WHAT IS A SUPERMOON?
A supermoon occurs when a full or new moon coincides* with the Moon’s closest approach to the Earth.
The Moon’s orbit around Earth is not perfectly circular. This means the Moon’s distance from Earth varies as it goes around the planet. The closest point in the orbit, called the perigee, is roughly 45,000km closer to Earth than the farthest point of the orbit. A full moon that happens near the perigee is called a supermoon.
So why is it super? The relatively close proximity* of the Moon makes it seem a little bit bigger and brighter than usual, though the difference between a supermoon and a normal moon is usually hard to notice unless you’re looking at two pictures side by side.
HOW DOES A LUNAR ECLIPSE WORK?
A lunar eclipse happens when the Earth’s shadow covers all or part of the Moon. This can only happen during a full moon, so first, it helps to understand what makes a full moon.
Like the Earth, half of the Moon is illuminated by the Sun at any one time. A full moon happens when the Moon and the Sun are on opposite sides of the Earth. This allows you to see the entire lit-up side, which looks like a round disc in the night sky.
If the Moon had a totally flat orbit, every full moon would be a lunar eclipse. But the Moon’s orbit is tilted by about 5 degrees relative to Earth’s orbit. So, most of the time a full moon ends up a little above or below the shadow cast by the Earth.
But twice in each lunar orbit, the Moon is on the same horizontal plane as both the Earth and Sun. If this corresponds to a full moon, the Sun, the Earth and the Moon will form a straight line and the Moon will pass through the Earth’s shadow. This results in a total lunar eclipse.
To see a lunar eclipse, you need to be on the night side of the Earth while the Moon passes through the shadow. The best place to see the eclipse on May 26, 2021, will be Australia, the middle of the Pacific Ocean, the East Coast of Asia and the West Coast of the Americas.
WHY DOES THE MOON LOOK RED?
When the Moon is completely covered by Earth’s shadow it will darken, but doesn’t go completely black. Instead, it takes on a red colour, which is why total lunar eclipses are sometimes called red or blood moons.
Sunlight contains all colours of visible light. The particles of gas that make up Earth’s atmosphere are more likely to scatter blue wavelengths of light while redder wavelengths pass through. This is called Rayleigh scattering, and it’s why the sky is blue and sunrises and sunsets are often red.
In the case of a lunar eclipse, red light can pass through the Earth’s atmosphere and is refracted – or bent – toward the Moon, while blue light is filtered out. This leaves the Moon looking pale reddish during an eclipse.
Hopefully you will be able to go see this super lunar eclipse. When you do, now you will know exactly what makes for such a special sight.
This story was first published on The Conversation and is republished with permission.
WHEN TO WATCH
It will take about three hours for the Moon to pass through Earth’s shadow, so a partial eclipse will be visible about 90 minutes before and after the total lunar eclipse. The actual eclipse will take about 15 minutes.
In Australia’s eastern states the total lunar eclipse will begin at 9.11pm and end at 9.25pm on Wednesday May 26.
In South Australia and the Northern Territory the eclipse will begin at 8.41pm and end at 8.55pm.
In Western Australia the eclipse will begin at 7.11pm and end at 7.25pm.
- coincides: happens at the same time
- proximity: how close something is to something else
- What three Moon events are going to happen at once?
- What makes it a supermoon?
- By how many degrees is the Moon tilted compared to the Earth’s orbit?
- What is Rayleigh scattering?
- When will you be able to see the eclipse where you are?
LISTEN TO THIS STORY
1. Lunar Invitation
Design and create an invitation to the super lunar event happening in Australia on May 26. Use the facts from the Kids News article and make your invitation bright, bold and informative so whoever you give it to, knows exactly when and what to see.
Distribute your invitation to a family, friend or neighbour so they know about this special event.
Time: allow 30 minutes to complete this activity
Curriculum Links: English, Science
Draw a diagram illustrating how a supermoon works from the explanation given in the article. Make it as straightforward and simple as possible to show younger prep students what is happening.
Time: allow 15 minutes to complete this activity
Curriculum Links: English, Science
The Day the Earth lost its Moon
On the 26th day of May 2021, disaster struck the Earth. Humans stood huddled together staring in awe as the full Moon turned blood red. It then illuminated brighter than ever before, all before it was slowly sucked deep into space sending Earth into complete darkness.
Complete this narrative about the day the Earth lost its Moon.
How will your story end?
Did something happen before the event that needs to be told?
Don’t forget your VCOP and to edit your story to see how it sounds when it is read aloud.