The Moon is going to be doing some fairly freaky things in the wee hours of Saturday morning this week.
So you don’t miss out on this spectacular astronomical happening, we’ve asked an actual astronomer to let us in on some space secrets (read: science) and the how, what, where, and why of July’s blood moon.
Josh Pritchard is a scientist and an astronomy guide at Sydney Observatory (just to be clear—we’re talking astronomy guys, not astrology), and he knows a thing or two about moons, planets, our solar system, and stargazing. So let’s get Josh to break down everything you need to know about this epic eclipse.
This whole "Blood Moon" thing sounds really cool. So what is it exactly?
A lunar eclipse occurs when the Moon, Earth, and Sun are all aligned so that the Earth's shadow falls on the Moon. The shadow of the Earth is big and covers a larger patch of sky than the Moon takes up. A total lunar eclipse only happens when the moon passes through the darkest central part of the shadow, called the umbra.
I've seen some pretty eerie images of a red moon. What will it look like exactly?
At first you won't see much, so if you're late waking up don't stress! We will first see the Earth's shadow begin to bite into the full Moon at around 4:24am. You’ll really be able to appreciate the Earth’s roundness at this point—flat earthers take note! Over the next hour the shadow will creep across the Moon’s surface during the partial stage, until finally at around 5:30am AEST, it will fully encompass the Moon, revealing a deep blood red hue. Totality!
Ok, when can I see it in Sydney?
Not all lunar eclipses come equal—this eclipse is going to be the longest of the 21st century at 1 hour and 43 minutes of totality. We will miss the last 20 minutes in Sydney, but we will have a good view from about 5.30am through to the Moon setting still fully eclipsed at 6.55am.
I'm setting my alarm as we speak. Where will be the best spot to see it?
On the East coast the Moon will be headed low towards the west, so you should view the eclipse from somewhere with a good view of the western horizon. It will be bright and obvious!
Last question. Why does the moon turn red?
That’s sort of a similar question to why the sky is blue. Once ‘totality’ begins and the Moon is completely within the ‘umbra’, almost all of the light coming from the Sun is blocked. Very little of the green or blue light makes it past the Earth, as the atmosphere causes these colours to scatter in random directions, lightening the atmosphere and giving us a blue sky. The red light is not scattered by the atmosphere as strongly, but is instead refracted or bent towards the Moon, as though the Earth were a giant lens.
If you could stand on the Moon during a total lunar eclipse you would see the Earth encircled by a red ring of light—our thin atmosphere glowing with the light of every sunrise and sunset on the Earth at once.
If you’re keen to join a crew of astronomers for moon-viewing on Saturday morning, Sydney Observatory will be open from 5am. And if 4am alarms ain't your thing, check out the nightly tours at Sydney Observatory running through until September, where you will see Mars the closest it has been since 2003.
Image credit: Celso.