An extraordinary string of four total lunar eclipses is about to illuminate our skies starting on 15 April 2014. In the early hours of tomorrow morning, our pale Moon will turn blood orange red.
This spectacle will mark the first of four consecutive total lunar eclipses, a series known as a tetrad. A lunar eclipse occurs when the Moon dips behind Earth’s shadow. Most eclipses are partial, meaning only portions of the Moon are hidden from the Sun. But sometimes the Moon, Earth and Sun perfectly align so that the entire Moon is shielded from the Sun’s rays. When this happens, wayward beams of sunlight filter through Earth’s atmosphere, colouring the Moon a fiery red, resulting in a total eclipse.
The total eclipse of 15 April 2014 will be followed by another on 8 October 2014, another on 4 April 2015, and another on 28 September 2015.
Who will get to see it?
The entire event is visible from both North and South America. Observers in the western Pacific miss the first half of the eclipse because it occurs before moonrise. Likewise most of Europe and Africa experience moonset just as the eclipse begins. None of the eclipse is visible from north/east Europe, eastern Africa, the Middle East or Central Asia.
According to Timeanddate.com, the total phase of this lunar eclipse is not visible in Cape Town, South Africa, but it can be observed there as a penumbral lunar eclipse. A penumbral lunar eclipse is when the Moon passes through the pale outskirts of Earth’s shadow. It’s so subtle, sky watchers often don’t notice an eclipse is underway.
While a tetrad itself isn’t rare, Nasa scientists say that its visibility across the entire United States is unique.
Tomorrow’s eclipse begins at 2 am Eastern time US (8 am GMT+2) when the edge of the Moon first enters the amber core of Earth’s shadow. Totality occurs during a 78 minute interval beginning around 3 am (9 am GMT+2) in the morning on the US east coast, midnight on the US west coast.
Why will the Moon appear red?
A quick trip to the Moon provides the answer: Imagine yourself standing on a dusty lunar plain looking up at the sky. Overhead hangs Earth, nightside down, completely hiding the sun behind it. The eclipse is underway.
You might expect Earth seen in this way to be utterly dark, but it’s not. The rim of the planet is on fire! As you scan your eye around Earth’s circumference, you’re seeing every sunrise and every sunset in the world, all of them, all at once. This incredible light beams into the heart of Earth’s shadow, filling it with a coppery glow and transforming the Moon into a great red orb.
Watch the video to explore how lunar eclipses work and to learn about the different types that occur…