As the moon rises on Friday night, those looking up at the sky will be treated to a rare sight when a total lunar eclipse turns it a striking “blood” red.
The moon passes into Earth’s shadow in the early evening of Friday, March 14.
The entire moon will move into the darkest part of the shadow, known as the Umbra — blocking sunlight from reaching it. The moon will turn red for a few hours until it finishes passing through the Umbra.
Stardome astronomer Josh Aoraki told 1News the eclipse would begin as soon as the moon rises at 7.38pm on Friday. It will reach its totality between 8pm and 8.30pm and will end by 11pm.
Aoraki said the weather was the most significant factor in whether or not you’d be able to see the eclipse.
“So you just need a clear sky. So check the forecast for your local area,” he said.
According to MetService’s extended forecast, the North Island could expect a few isolated showers around the Bay of Plenty and Coromandel on Friday, but it will be “mainly fine” elsewhere. A shower in the southwest is possible later.
The South Island could expect a few showers in the west, which will turn to rain late about Fiordland. However, it will be mainly fine elsewhere, with isolated showers about Otago and Southland clearing.
If you catch any good photos of the eclipse, email them to [email protected] with the subject line “Lunar”.
Aoraki said that because the eclipse will already be happening, the moon would be “really low” in the sky.
“So you basically want a really clear, unobstructed view of the eastern horizon.”
He recommended going to the top of a local maunga and bringing some binoculars or a camera.
“It’s definitely great to get those out ’cause you see more details of the moon.
“But the beauty of a lunar eclipse is you don’t need any special equipment. You can just look at the moon.”
Why does the moon turn red?
According to NASA, some sunlight will still pass through Earth’s atmosphere and reach the moon’s surface during an eclipse, giving it a striking and dim red glow.
This is because colours with shorter wavelengths, like blues and violets, scatter more easily than those with longer wavelengths, like red and orange.
“Because these longer wavelengths make it through Earth’s atmosphere, and the shorter wavelengths have scattered away, the Moon appears orangish or reddish during a lunar eclipse.”
The same thing happens here on Earth.
“When the Sun is high on a clear day, we see blue light scattered throughout the sky overhead.
“At sunrise and sunset, when the Sun is near the horizon, incoming sunlight travels a longer, low-angle path through Earth’s atmosphere to observers on the ground.
“The bluer part of the sunlight scatters away in the distance (where it’s still daytime), and only the yellow-to-red part of the spectrum reaches our eyes.”
The more dust or clouds in Earth’s atmosphere during the eclipse, the redder the moon will be.