Now We're No Longer Alone: Once in a Super Blue Blood Moon

Tomorrow's moon will delight the northern hemisphere and parts of Asia with three astrological events: a total lunar eclipse, a blue moon and an almost super moon. You won't need a telescope, but a dark spot from which to observe is highly recommended.

The last time these events coincided was on March 31, 1866, and – after January 31 – this auspicious occasion isn't due to happen again until December 31, 2028.

RELATED:

Newly Discovered Asteroid Passes Close to Earth

What does it mean to have a super blue blood moon? And what exactly can we expect to see?

The moon will be at a distance of 384,000 kilometers from Earth and will appear 30 times brighter and 14 times closer than usual, hence the name 'super.'

In a total lunar eclipse, the full moon is completely obscured by Earth's shadow, making it seem blood red during its partial phase.

So why are we calling it a blue moon?

There are two lunar events that carry this title. A lunar year consists of four three-moon periods in relation to the astronomical seasons. There are normally three full moons between an equinox and a solstice.

A blue moon is the third full moon in a four full-moon astronomical season. That's the first lunar event.

In 1946, amateur astronomer James Hugh Pruett incorrectly defined a blue moon as the second full moon in a month, which led to the naming of the second lunar event. This is what the northern hemisphere and parts of Asia will witness on January 31.

That said, neither of the definitions mean the moon will actually appear blue. Rather, because of the total lunar eclipse, the moon will appear blood red.

An actual blue moon appears only under very specific atmospheric conditions, meaning it's an earthly event rather than a lunar one. In the event of a forest fire, volcanic eruption or dust storm, dust particles larger than 0.7 microns (0.00007 centimeters) enter the atmosphere and scatter the moon's red light, making it seem blue to the human eye: a very rare occurence indeed.

The event on January 31 marks the first blue moon of the year, according to its monthly definition. The second is due on March 31.

Blue moons occur every two or three years, but two 'monthly' blue moons in the space of 12 months are less common. This event won't happen again until 2037; two 'seasonal' blue moons can't happen in one year.

This time, the blue moon is due to appear at 13:27 UTC.