Lucky sky-watchers are about to get a cosmic three-for-one deal, as the second super-size full moon in a month undergoes a dramatic total lunar eclipse on January 31. According to eclipse experts, the event marks the first time anyone on Earth has seen this celestial trifecta in 35 years.
On the 31st, the moon will officially reach its full phase at 11.50pm, in Victoria and NSW until 12.30am February 1st. For those living on the West Coast of Australia, look to the skies at 7.30pm- 11pm Jan 31st.
This is the second full moon to occur in a calendar month, an event commonly referred to as a blue moon. Around the same time, the full moon will be making an especially close approach to Earth, a phenomenon popularly called a supermoon.
Adding to the space oddity, viewers in some parts of the world will also see a total lunar eclipse on the 31st. When the eclipse hits its peak, the moon’s face can sometimes take on a reddish tone, earning it the moniker of blood moon.
LUNAR ECLIPSE 101: Nicknamed "blood moon," some ancient cultures regarded a total lunar eclipse as an ominous event. Today, this celestial phenomenon generates excitement and wonder. Learn what causes a lunar eclipse and how it gains its crimson colouring
The most visually impressive part of this lunar show promises to be the total eclipse. Lunar eclipses happen when Earth is between the moon and the sun, so that the moon passes through Earth’s shadow.
Eclipses don't happen every month, because the moon's orbit is tilted with respect to ours, so the lunar orb usually passes above or below Earth's shadow. Our planet's shadow completely engulfs the moon’s face twice a year, on average.
WHERE WILL THE ECLIPSE BE VISIBLE?
For this month’s super blue blood moon, the best views will be for people on the northern part of North America’s West Coast, as well for viewers across China, Japan, and most of Australia. Observers there will witness the entire eclipse from beginning to end during the early morning hours of January 31.
Observers in parts of western South America, most of North America, India, and eastern Eurasia will get to see a partial eclipse, while sky-watchers in large swaths of Africa and South America will miss the show.
WHAT MAKES THE MOON TURN RED?
Although the moon is in shadow during a total eclipse, sunlight shining through Earth's atmosphere gets bent, or refracted, toward the red part of the spectrum and is cast onto the moon's surface. As a result, the lunar disk goes from a dark gray color during the partial phase of the eclipse to a reddish-orange color during totality.
The moon's color during totality can vary considerably depending on the amount of dust in Earth's atmosphere at the time. Active volcanoes spewing tons of ash into the upper atmosphere, for instance, can trigger deep blood-red eclipses.
While no one can predict exactly what color we'll see before each eclipse, based on current activity, expectations are that this total eclipse will be a dramatic brilliant orange.
WHAT HAPPENS IF I CAN’T SEE TOTALITY?
If you get clouded out or it’s daytime where you are at the time of the eclipse, you can still tune in to the show online via webcasts such as the Virtual Telescope Project and Slooh. And if you happen to miss out this time around, the next total lunar eclipse will arrive on July 27 and will be visible from Asia, Australia, Africa, Europe, and South America.
Lead image: A total lunar eclipse on September 27, 2015, was also a so-called supermoon, when the moon is at its closest point to Earth in its orbit. PHOTOGRAPH BY TIM LAMAN, NATIONAL GEOGRAPHIC CREATIVE
This article has been changed slightly for Australian readers.