March 16, 2015, by Emma Thorne
Solar Eclipse 2015: what you need to know
It’s the biggest solar eclipse in the UK since 1999 and is set to plunge some parts of the country into near darkness on Friday morning. PhD student Rebecca Kennedy from the School of Astronomy and Physics gives the low down on what you need to know about this celestial phenomenon — and how you can safely view it.
What is a total solar eclipse?
A total solar eclipse happens when the Moon passes between the Sun and the Earth, completely blocking out the Sun’s light for up to 7 1/2 minutes. The Moon’s shadow is cast onto the Earth and temperatures plummet by up to 20 degrees, animals start preparing for bed, and a few people get ready to propose to their significant other!
When do solar eclipses happen?
The Moon’s orbit isn’t exactly circular, and doesn’t always line up with the Sun on each orbit, so total eclipses only happen every couple of years. Eclipses only happen when there is a ‘New Moon’, i.e. the moon isn’t visible in the night sky.
How can I view the solar eclipse?
Your best bet is to take a quick trip to Norway to see the total solar eclipse, but if your private jet isn’t available on Friday morning you can still see a partial solar eclipse from the UK from about 8:30am. It’s incredibly dangerous to look directly at a solar eclipse, so it’s best viewed through a pinhole projector or through a pair of solar eclipse glasses.
What is the ‘Diamond Ring’ phase of an eclipse?
As anyone who has seen Wallace & Gromit on their Grand Day Out will know, the surface of the Moon is anything but smooth. Once the Moon is almost completely blocking out the Sun, light shines through valleys on the Moon’s surface, looking like little balls of light. This effect is called ‘Baily’s Beads’, which turns into the ‘Diamond Ring’ when there is only one bead of light left shining through just one valley.
What other types of eclipse are there?
Partial solar eclipses — which is what we’ll be able to see from the UK on Friday — occur when the Moon doesn’t completely block out the Sun.
Annular solar eclipses occur when the Moon is at the furthest point of its orbit, so it appears slightly smaller than the Sun when viewed from the Earth. This creates a ring of light around the edge of the Moon.
Lunar eclipses occur when the Earth passes between the Sun and a full Moon, and are safe to view with the naked eye.
Can a lunar eclipse save you from angry locals when stranded in a foreign land?
Yes! Christopher Columbus used this tactic when he was stranded on his travels in 1504. Being a bit of a Renaissance man, he knew that a lunar eclipse was imminent. He told the locals that if they didn’t help his men, the Moon would disappear. Luckily his calculations were correct, the Moon was indeed eclipsed and Columbus and his men lived to see another day.