Rare blood supermoon to grace NZ skies for first time in 40 years

A blood supermoon in England.
A blood supermoon in England. Photo credit: Getty Images

A rare space spectacle is set to grace New Zealand skies next Wednesday - a blood supermoon.

The phenomenon occurs when there is the rare combination of a blood moon and a supermoon on the same night, and it last occurred in New Zealand 40 years ago in 1982.

Stardome Observatory & Planetarium astronomy educator John Rowe explained the supermoon occurs when a full Moon phase coincides with the Moon’s closest approach to Earth. 

"The Moon's orbit around Earth is an ellipse, not a circle, so its distance from Earth can vary from 406,000km at the furthest point of the ellipse (the apogee) to 357,000km at the closest (the perigee)," he said. "A supermoon, which happens at perigee, will appear 14 percent bigger and 30 percent brighter than its opposite, a micro moon."

The blood moon, which is also known as a total lunar eclipse, occurs when the Earth lines up between the Moon and the Sun, hiding the Moon from sunlight and blocking most of the blue light. The remaining light refracts onto the Moon's surface causing a red glow.

Rowe said it is particularly "exciting" that the two celestial events were occurring at the same time, resulting in a blood supermoon.

Kiwis will be able to view the spectacle next Wednesday, May 26, as long as the weather isn't too cloudy.

"Since it will be occurring late in the evening, the Moon will be high in the sky throughout, and therefore is less likely to be obstructed by cloud (emphasis on 'less' likely)!  It won’t matter where you are in New Zealand - as long as the clouds stay away, you will see this eclipse."

The lunar eclipse will last for five hours, from 8:47pm to 1:49am on the 27th, while the blood moon will only last for 14 minutes from 11:11pm to 11:25pm.

"All Kiwis need to do is look high into the night sky on Wednesday evening and they’ll be treated to a stunning sight," Rowe said.