'Supermoon trilogy' about to begin - NASA

If you can't stay up to watch Monday night's supermoon, you'll be over-the-moon to hear it's just the first of three in the next few months.

NASA's taken a leaf out of Hollywood's book and billed it the 'Supermoon Trilogy'.

"Supermoons are a great opportunity for people to start looking at the moon - not just that once, but every chance they have," said Noah Petro, research scientist at NASA's Goddard Space Flight Center.

The moon's orbit is elliptical, and when it's at its closest to Earth it appears 14 percent bigger and 30 percent brighter than normal.

A NASA image showing how much bigger and brighter a 'supermoon' is compared to a normal full moon.
A NASA image showing how much bigger and brighter a 'supermoon' is compared to a normal full moon. Photo credit: NASA

Monday's lunar largesse will be followed by a second supermoon on January 2 (NZ time), but it's the third that has skygazers especially excited.

On the night of January 31 (NZ time), the supermoon will also be a 'blue moon' - the second full moon in a calendar month.

Not only that, but in some parts of the world - including New Zealand - it will coincide with a lunar eclipse, making it both a blue moon and a 'blood moon'.

The moon will move into the shadow of the Earth at 11:51pm, ahead of the full eclipse at 1:51am. By 5am, the moon will be back in the full light of the sun.

It's called a 'blood moon' because light passing through the Earth's atmosphere is bent into a red hue.

"We're seeing all of the Earth's sunrises and sunsets at that moment reflected from the surface of the moon," said Sarah Noble, NASA scientist.

A 2015 supermoon photographed in Kashmir.
A 2015 supermoon photographed in Kashmir. Photo credit: Getty

Lunar eclipses happen about twice a year. Blue moons occur every two-and-a-half years.

None of the coloured moons should be considered harbingers of doom.

Newshub.

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