'Super blue blood moon': stargazers prepare for rare celestial event

Extract from The Guardian

The moon

Blue moon, super moon and blood moon combine to create moment not seen in the skies in more than 150 years

Guardian staff

Sun 28 Jan 2018 23.48 AEDT First published on Sun 28 Jan 2018 16.12 AEDT

A rare celestial event will grace the skies during the coming week when a blue moon and lunar eclipse combine with the moon being at its closest point to Earth, resulting in what is being called a “super blue blood moon”.

The trifecta will take place on 31 January and will be best visible from the western hemisphere. The last time the three elements combined at the same time was in 1866.

A “super blue blood moon” is the result of a blue moon – the second full moon in a calendar month – occurring at the same time as a super moon, when the moon is at perigee and about 14% brighter than usual, and a so-called blood moon – the moment during a lunar eclipse when the moon, in the Earth’s shadow, takes on a reddish tint.
Stargazers living in the US will be able to see the eclipse before sunrise on Wednesday, according to Nasa. For those in the Middle East, Asia, eastern Russia, Australia and New Zealand, the event will be visible during moonrise on the morning of 31 January.
“For the [continental] US, the viewing will be best in the west,” said Gordon Johnston, program executive and lunar blogger at Nasa. “Set your alarm early and go out and take a look.”

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“Weather permitting, the west coast, Alaska and Hawaii will have a spectacular view of totality from start to finish,” said Johnston. “Unfortunately, eclipse viewing will be more challenging in the eastern time zone. The eclipse begins at 5.51am ET, as the moon is about to set in the western sky, and the sky is getting lighter in the east.”
The eclipse itself is expected to last about an hour and a quarter. For anyone unable to watch the event in person, it will be streamed live online.
Nasa said the eclipse will offer scientists a chance to see what happens when the surface of the moon cools quickly.

“The whole character of the moon changes when we observe with a thermal camera during an eclipse,” said Paul Hayne of the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder. “In the dark, many familiar craters and other features can’t be seen, and the normally nondescript areas around some craters start to ‘glow’ because the rocks there are still warm.”