What is the super blue blood moon?
A rare celestial event that hasn’t been seen by much of the world in more than 150 years is set to grace the skies on Wednesday.
A ‘super blood blue moon’ will be visible on 31 January, with western North America, Asia, the Middle East, Russia and Australia getting the best view of the stunning phenomena.
The event is causing a buzz because it combines three unusual lunar events – an extra big super moon, a blue moon and a total lunar eclipse.
It’s the third in a series of ‘super moons,’ when the moon is closer to Earth in its orbit – known as perigee – and about 14 percent brighter and 30 per cent larger than usual.
It’s also the second full moon of the month, commonly known as a ‘blue moon’, which happens every two years and eight months.
The super blue moon will pass through Earth’s shadow to give viewers in the right location a total lunar eclipse.
While the moon is in the Earth’s shadow it will take on a reddish tint, known as a ‘blood moon.’
Sunlight manages to reach the moon but first it has to pass through Earth’s atmosphere.
This makes the sky redder (as it scatters away shorter shorter wavelengths of light) and also bends the path of the light, directing it into the shadow.
When and how can you see it?
Experts say the best viewing in the US will be from the west.
‘Set your alarm early and go out and take a look’, said Gordon Johnston, program executive and lunar blogger at NASA Headquarters in Washington.
‘Weather permitting, the West Coast, Alaska and Hawaii will have a spectacular view of totality from start to finish’.
‘Unfortunately, eclipse viewing will be more challenging in the Eastern time zone. The eclipse begins at 5:51 AM EST (10:51 GMT), as the moon is about to set in the western sky, and the sky is getting lighter in the east.’
For people viewing the event from New York or Washington, the moon will enter the outer part of Earth’s shadow at 5:51 am (10:51 GMT) but will hardly be noticeable.
The darker part of Earth’s shadow will begin to blanket part of the moon with a reddish tint at 6:48 am EST (11:48 GMT), but the moon will set less than a half-hour later.
‘So your best opportunity if you live in the East is to head outside about 6:45 a.m. and get to a high place to watch the start of the eclipse—make sure you have a clear line of sight to the horizon in the west-northwest, opposite from where the Sun will rise,’ said Dr Johnston.
If you live in the Central time zone, viewing will be better, since the action begins when the moon is higher in the western sky.
At 4:51 a.m. CST (10:51 GMT, 05:51 EST) the penumbra – or lighter part of Earth’s shadow – will touch the moon.
By about 6:15 a.m. CST (12:15 GMT, 07:15 EST) the Earth’s reddish shadow will be clearly noticeable on the moon.
The eclipse will be harder to see in the lightening pre-dawn sky, and the moon will set after 7:00 am (13:00 GMT, 08:00 EST) as the Sun rises.
In the Rocky Mountain region, the show begins as the umbra touches the edge of the moon at 4:48 a.m. MST (11:48 GMT, 06:48 EST).
The super blue moon will pass through Earth’s shadow to give viewers in the right location a total lunar eclipse. While the Moon is in the Earth’s shadow it will take on a reddish tint, known as a ‘blood moon’
The peak of the blood moon eclipse is at about 6:30 am (13:30 GMT, 8:30 EST) local time, and the moon will set shortly after 7 am (14:00 GMT, 9:00 EST).
Californians and viewers in western Canada will be treated to the total eclipse phase from start to finish, though the penumbral shadow will pass after the moon has set.
The umbral eclipse begins at 3:48 am Pacific Time (11:48 GMT, 06:48 EST). At 4:51 am (12:51 GMT, 7:48 EST), totality will begin, with best viewing between about 5:00 and 6:00 am local time.
The totality phase ends about 6:05 am (14:05 GMT, 09:05 EST).
Weather permitting, eclipse fans in Hawaii will experience the lunar eclipse from start to finish, as will skywatchers in Alaska, Australia and eastern Asia.
In the UK, the moonrise will occur sometime around 4.55pm GMT. But the the lunar eclipse – will not begin until halfway through the night when the moon passed though the Earth’s shadow.
The partial eclipse is expected to begin around 11.48am GMT, before reaching its peak at 1.29pm GMT.
Unlike a solar eclipse, this lunar eclipse can be safely viewed without protective eyewear.
For anyone unable to watch the event , it will be streamed online.
How rare is it?
While people in the eastern Hemisphere saw their last Blue Moon total lunar eclipse in 1982, for the Western Hemisphere, this eclipse will be the first blue moon total eclipse since 1866.
According to Sky and Telescope magazine, ‘the last time a complete lunar cover-up took place on the second full moon of the month was December 30, 1982, at least as reckoned by local time in Europe, Africa, and western Asia – locations where the event could be seen.’
That event also occurred at the moon’s orbital perigee, making it an extra bright super moon.
According to Sky and Telescope, the last blue moon total lunar eclipse visible from North America happened on March 31, 1866.
‘But on that date the moon was near apogee, its most distant point from Earth,’ it said.
Why is it important for science?
According to experts from Nasa, the event will also offer experts a chance to see what happens to the moon when it cools quickly.
This information will help them understand characteristics of the regolith — the mixture of soil and loose rocks on the surface — and how it changes over time.
‘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.’
Normally, the transitions into and out of darkness and the temperature changes that go with them, are spread over the course of a lunar day (29-and-a-half days).
‘During a lunar eclipse, the temperature swing is so dramatic that it’s as if the surface of the moon goes from being in an oven to being in a freezer in just a few hours,’ said Noah Petro, deputy project scientist for NASA’s Lunar Reconnaissance Orbiter, or LRO, at Goddard Space Flight Center in Greenbelt, Maryland.
From the Haleakala Observatory on the island of Maui in Hawaii, the team will conduct their investigations at invisible wavelengths where heat is sensed.
They’ve done this kind of study a few times already, singling out individual lunar locations to see how well they retain warmth throughout the eclipse.
How quickly or slowly the surface loses heat depends on the sizes of the rocks and the characteristics of the material, including its composition, how porous it is and how fluffy it is.
By comparing the two types of observations, the team is able to look at variations in particular areas — say, the lunar swirls at Reiner Gamma or an impact crater and the loose debris around it.
This kind of information is useful for practical purposes such as scouting out suitable landing sites. It also helps researchers understand the evolution of the surface of the moon.
‘These studies will help us tell the story of how impacts large and small are changing the surface of the moon over geological time,’ said Dr Petro.