Blood Moon: Total Lunar Eclipse Viewer’s Guide

Skywatchers in the right location on Earth will get a front row seat to watch the full moon get painted red in the last total lunar eclipse until 2025.  The perfect alignment of the Sun, Earth and Moon creates one of nature’s most eye-catching phenomena that allows all of Earth’s sunrises and sunsets to be painted onto the moon’s disk in our skies – how cool is that!

Photo by Yu Kato 

Where and When will it be Visible?

The best locations on Earth to witness this event will be across western North America where the entire event will be visible on the morning of November 8th, with the partial eclipse phase beginning an hour or so after midnight. ” Meanwhile in Hawai‘i, the totally eclipsed Moon will be directly overhead. Viewers in the central parts of the continent will see all of totality and most of the final partial phases, while those on the East Coast can watch the Sun rise as totality ends. ” according to Sky and Telescope

Credit: Gregg Dinderman / Sky & Telescope; Source: USNO

“South America will witness the initial phases of the eclipse up to totality, while Central America can enjoy the show a bit longer and see it through the total phase. The eclipse is an early evening event in central and eastern Asia, Australia, and New Zealand, and the Moon rises either during the earlier partial phases or during totality,” added Sky and Telescope.

Credit: Gregg Dinderman / Sky & Telescope; Source: USNO

Credit: Sky and Telescope

Watch Online

If you are clouded out or on the wrong side of the Earth when this eclipse unfolds you can still enjoy it virtually by joining one of the many livestreams from Americas, Japan, and many other countries. Check out the eclipse livestream collection page put together by the non-profit Astronomers Without Borders (which I help out đŸ˜‰)

Why does the Moon Turn Red?

During a lunar eclipse, Earth’s atmosphere scatters sunlight. The blue light from the Sun scatters away, and longer-wavelength red, orange, and yellow light pass through, turning our Moon red. *This image is not to scaleCredit: NASA Goddard Space Flight Center/Scientific Visualization Studio

A lunar eclipse occurs when Earth is positioned between the Sun and the Moon. Earth casts a shadow on the Moon. During a total lunar eclipse, the entire Moon passes through Earth’s shadow. The Moon becomes darkened by the shadow until it is completely covered and glows a bright orange or red. This is caused by light passing through Earth’s atmosphere. The blue wavelengths of sunlight are scattered by dust and pollution particles in Earth’s atmosphere.  The remaining red wavelengths of light are bent by Earth’s atmosphere and illuminate the Moon.  The more dust and pollution in Earth’s atmosphere during the time of a total lunar eclipse, the stronger and deeper the red colour will be. This is the same reason why sunsets appear orange-red. 

Artist’s depiction of the Earth during a lunar eclipse from the surface of the Moon. Credit: NASA Goddard Space Flight Center/Scientific Visualization Studio

 In June 1991, Mount Pinatubo volcano in the Philippines erupted in the second largest volcanic explosion of the 20th century.  The eruption threw billions of tons of ash and dust high in Earth’s atmosphere that circled Earth for over a year.  The lunar eclipses that followed in 1992 were so deep red that some people saw the eclipsed Moon completely disappear in the sky. 

Credit: NASA

Omens in the Sky

Eclipses have long been a source of mystery and spectacle, and have been generally considered omens of bad things to come. From Asian, European to Islamic countries, ancient historical records are full of references connecting eclipses with dark events that followed soon afterward, such as the death of a king or a wide famine. 

This illustration dating to 1879 shows a group of indigenous people in South America during the lunar eclipse which Christopher Columbus predicted occured on Feb. 29, 1504. (Camille Flammarion (Astronomie Populaire 1879) via Wikimedia Commons)

Many traditions believed that some mythological creature swallowed up the moon.  The Maya of Central America thought it was a jaguar, the Chinese saw a three legged toad, while some Europeans believed a red demon was consuming the Moon during an eclipse. Even today, lunar eclipses are associated in Iraq with a popular children story of a moon that is eaten by a great big whale.

For modern skywatchers there remains no mystery behind eclipses but they are still great showcases for the clockwork of the universe. When Earth’s shadow slowly engulfs the Moon during an eclipse, you can see that its shape is the arc of a circle. Two and a half thousand years ago, this curved shadow may have convinced Pythagoras, the Greek astronomer and mathematician, that the Earth was round.

Why don’t we see a lunar eclipse every month, when the moon is full?

The Moons orbit around Earth is titled at a slight angle with respect to Earth’s own orbit around the Sun. As a result the Moon usually passes either above or below the Earth’s shadow, missing it completely and allowing us to see the familiar full Moon. So for us to see an eclipse of the Moon, there must be a perfect alignment of all three – making it a special event indeed. (Photo Credit: NASA)

Generally two lunar eclipses occur each year, separated by 6 months. Unfortunately, if the full Moon is not visible in the night sky from your part of the world during eclipse time you can be out of luck.

After Tuesday’s eclipse skywatchers are in for a dry spell as this exact cosmic line-up won’t occur again until March 14, 2025 – the next total lunar eclipse – leaving us with only partial eclipses – next one occurring in October 28/29, 2023 where only a chunk of the Moon appears to be gobbled up by Earth’ Shadow.