Despite this morning's inversion layer NIWA forecasters say skies are looking good for spotting the Super Blood Moon tonight (Wednesday 26 May). 

A Super Blood Moon is a rare combination of three factors: a full Moon, the Moon being at its closest point to Earth in its orbit, and a total lunar eclipse.

Between 11:11pm and 11:25pm tonight the Moon will appear rusty red in colour and larger than usual. The red colour is due to the Earth blocking the Sun’s light and only heavily filtered light reaching the Moon.

The MetService is forecasting clear skies this evening which should make for excellent viewing of the Blood Moon.

What makes a supermoon super?

The supermoon phenomenon occurs when a full Moon coincides with the Moon’s closest approach to Earth. The Moon’s orbit around Earth is an ellipse 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). 

A supermoon that happens at perigee, will appear 14% bigger and 30% brighter than its opposite, a micromoon. 

And the total lunar eclipse?

The second celestial event for tonight is a total lunar eclipse, also known as a ‘blood moon’.

The total lunar eclipse starts once the moon is completely inside the umbra. And the moment of greatest eclipse happens with the Moon is halfway through the umbra as shown in this graphic IMAGE: NASA

This happens when the full Moon, Earth, and the Sun line up.

During a total lunar eclipse, Earth blocks direct sunlight from reaching the Moon. From the Moon’s perspective, the Sun is behind Earth, resulting in the Earth’s shadow falling on the Moon instead of the Sun’s rays.

The eclipse will last five hours, beginning at 8:47pm and concluding at 1:49am. However, the period of the blood moon will be very brief, lasting only 14 minutes from 11.11pm to 11.25pm.