PARIS: The longest “blood moon” eclipse this century began on Friday, coinciding with Mars’ closest approach in 15 years to treat skygazers across the globe to a thrilling celestial spectacle.

Unlike with a solar eclipse, viewers will need no protective eye gear to observe the rare display.

“All you have to do is... go outside!”, the Royal Astro­nomical Society (RAS) in London said, adding that binoculars will be useful to observe the phenomenon.

For about half the world, the moon will be partly or fully in Earth’s shadow from 1714 to 2328 GMT — six hours and 14 minutes in all.

The period of complete eclipse — known as “totality”, when the moon appears darkest — will last from 1930 to 2113 GMT.

At the same time, Mars will hover near the moon in the night sky, easily visible with the naked eye.

Amateur astronomers in the southern hemisphere will be best-placed to enjoy the spectacle, especially those in southern Africa, Australia, India and Madagascar, though it will also be partly visible in Europe and South America.

Beside Lake Magadi, 100 kilometres southwest of the Kenyan capital Nairobi, husband and wife team Susan Murabana and Chu Owen set up their high-powered telescope for the local community to watch the event.

The isolated lake is far from urban light pollution, making it the perfect spot for planet-spotting.

“Mars, Pluto, Saturn, Ju­­p­­­­­iter, Venus — Mercury, that’s the one I really wan­ted to see,” said Owen, 39, as he used the Sky Map app on his mobile phone to locate planets. “It’s the planets I’m really excited to see.” The website www.timeanddate.com also offers the exact locations and timing of the ecli­pse as it moves from Friday into Saturday.

Our neighbouring planet will appear unusually large and bright, a mere 57.7 million kilometres (35.9 million miles) from Earth on its elliptical orbit around the sun.

“We have a rare and interesting conjunction of phenomena,” Pascal Des­camps, an astronomer with the Paris Observatory, said.

“We should have a coppery red tint on the moon with Mars the ‘Red Planet’ just next to it, very bright and with a slight orange hue itself.” A total lunar eclipse happens when Earth takes position in a straight line bet­w­een the moon and sun, blotting out the direct sunlight that normally makes our satellite glow whitish-yellow.

The moon travels to a similar position every month, but the tilt of its orbit means it normally passes above or below the Earth’s shadow — so most months we have a full moon without an eclipse.

When the three celestial bodies are perfectly lined up, however, the Earth’s atmosphere scatters blue light from the sun while refracting or bending red light onto the moon, usually giving it a rosy blush.

This is what gives the phenomenon the name “blood moon”, though Mark Bailey of the Armagh Observatory in Northern Ireland said the colour can vary greatly.

Published in Dawn, July 28th, 2018