Tonight, July 27, 2018, the longest total lunar eclipse of the 21st century will take place.
Totality will last for a 1 hour, 42 minutes and 57 seconds: only four minutes short of the theoretical, maximum possible duration. The fully eclipsed phase of the Moon will be visible across portions of six continents.
For about half the world, the moon will be partly or fully in Earth’s shadow from 1:14 p.m. to 7:28 p.m. ET — six hours and 14 minutes in all. The period of complete eclipse — known as “totality,” when the moon appears darkest — will last from 3:30 p.m. to 5:13 p.m. ET.
Europe and Africa will be able to see the eclipse sometime between sunset and midnight on 27 July, whilst most of Asia, Indonesia and Australia will view the eclipse sometime between midnight and sunrise on 28 July.
Sadly, the eclipse will not be visible at any time for those of us here in America.
While there will be 230 lunar eclipses in the 21st century, including 85 total lunar eclipses, there are a special set of conditions that need to all line up to create one that lasts the longest amount of time possible. While the Earth’s shadow often falls near or even on the full Moon, what’s occurring tonight is something truly special.
Although the total lunar eclipse today (July 27) won’t be visible for people across North America, and bad weather could threaten even the geographically lucky — in the digital age, no avid skywatcher is ever shut out.
So why does a total lunar eclipse like this cause the moon to look red?
NASA explains on their site (linked below), that a total lunar eclipse happens when the whole moon enters Earth’s shadow. Some sunlight still reaches the moon, but first it goes through Earth’s atmosphere. The atmosphere filters out most of the sun’s blue light, so the moon looks red.
Along with this phenomenal Super Blood Moon, Mars is closest to Earth than in 15 years at the same time that the longest “blood moon” in history is happening.
This brings me to the myth currently circulating around social media that the moon and Mars will be roughly the same size.
The fact that we will experience a spectacular blood moon at the same time that Mars makes one of its closest passes to Earth is causing people to exaggerate the truth. If that were true, “we’d be in big trouble given the gravitational pulls on Earth, Mars, and our moon!” the NASA website states.
Mars will more likely appear as a very bright star, and viewers will need no protective eye gear.
Mars has already gotten quite a bit of press this week. Earlier in the week, the European Space Agency announced that a radar system may have detected briny water body beneath the southern pole of the planet. The fiery planet will undoubtedly get some more press this weekend, but the “blood moon” will be the star of the show.
The Earth orbits the Sun in an ellipse, while the Moon revolves around the Earth in its own elliptical orbit. These orbits share some common properties, but are also different in a few important ways.
When the Sun, Earth, and Moon all properly align, and the Moon passes completely through the Earth’s umbral shadow, that’s when a total lunar eclipse occurs. But there’s a combination of factors that all come together to make an eclipse as long as possible.
At totality, expect to see a Moon 12% smaller in diameter than your largest supermoons. During maximum totality, the Moon should be unusually, evenly red all around. In order to get a total lunar eclipse, the Moon needs to pass fully into the path of Earth’s shadow. But for the longest eclipse possible, it needs a perfect alignment between the Sun, Earth and Moon; this means the Moon should pass perfectly through the middle of Earth’s umbral shadow.
Astrologically this Full Moon in Aquarius, combined with Mars’ close proximity, could make for some challenging moments globallty. Certainly changes are afoot!
Might be a good night to stay in with a good book or a good movie!
For more information about the Blood Moon/Lunar Eclipse, and how to watch it, please visit NASA’s site linked below.
Top photo by Derek Hart
Other images Stock Files/NASA