ST. GEORGE — This week, the sky will be awash with the “most super” of this year’s supermoons, NASA states. But that’s not all. A total lunar eclipse will take place at the same time – making Earth’s lunar nightlight appear both huge and blood-red during the early morning hours of Wednesday.
In Southern Utah, celestial gazers willing to rise early for the occasion should look toward the southwest close to the horizon, which is where the moon will be situated when the eclipse takes place. It will begin at 2:47 a.m., but the moon will not start taking on a reddish hue until 3:44 a.m. From there, the tone will deepen until the total eclipse occurs at 5:11 a.m., which is when the moon will appear completely red.
Seven minutes later, the moon will be in a maximum eclipse, and by 5:25 a.m., the show will be over as the moon drops below the horizon and disappears from sight, marking the final lunar eclipse 0f 2021. The next lunar eclipse is scheduled to appear May 15, 2022, according to TimeandDate.
Wednesday’s supermoon is the second of three for the year, but this moon is also at its closest approach to Earth during this lunar eclipse – the first of its kind in more than 2 1/2 years, NASA says.
A supermoon occurs when the moon is both full and at its closest point to earth. Because the moon travels around the Earth in an elliptical orbit, the moon’s distance from Earth fluctuates. If the moon happens to be full at its closest point during a full moon, it is a supermoon.
It’s that close proximity to Earth, about 28,000 miles closer to Earth than the farthest point of the orbit, that makes the moon appear larger and brighter in the night’s sky.
Total eclipse of Earth’s lunar nightlight
A lunar eclipse takes place when the Earth’s shadow covers all or part of the moon and can only be observed during a full moon – or when the moon and sun are on opposite sides of the Earth, an alignment that causes Earth to block part or all of the sun’s light creating a shadow on the lunar surface.
Since only half of the moon is illuminated by the sun at any one time, similar to the earth, this allows a full view of the moon that appears as a lighted disc in the night sky. But two times during each lunar orbit, the moon is on the same horizontal plane as both the Earth and sun, and if this happens to correspond with a full moon, the Earth, moon and sun form a straight line, and the moon will pass through the Earth’s shadow, forming a total lunar eclipse.
A lunar eclipse causes the moon to take on a rosy glow, according to NASA, since Earth’s atmosphere filters the light as it passes through, and red light travels in a straight path through the air – unlike blues and violets which scatter as they travel through the atmosphere.
Therefore, during a lunar eclipse, a portion of the heavily filtered morning and evening light escapes the Earth’s atmosphere and reaches the moon’s surface – dimly illuminating the lunar surface with a culmination of the red hues left over from sunrises and sunsets taking place all over the world at that time.
Put simply, red light can pass through the Earth’s atmosphere and is refracted – or bent – toward the moon, tinting it red, while blue light is scattered and filtered out. The more dust or clouds in Earth’s atmosphere the deeper red the moon will appear.
Bigger is faster but not always better
According to Space.com, one drawback to a lunar eclipse taking place during a supermoon is that a larger-than-normal lunar body is moving through an unusually smaller umbral shadow, which shortens the duration of the total eclipse. The moon is also moving faster since it is in perigee, which further reduces the amount of time it will spend completely immersed in Earth’s shadow.
The amount of time the moon will spend in a total lunar eclipse on Wednesday is roughly 15 minutes – but it promises to be a show-stopping 15 minutes for those with an eye turned toward the early morning horizon.
Copyright St. George News, SaintGeorgeUtah.com LLC, 2021, all rights reserved.