Wednesday 18 March 2015

Total Solar Eclipse to be visible from Faroe Islands, Svalbard, Friday 20 March 2015.

A total eclipse of the Sun will be visible from the Faroe Islands and Svalbard on Friday 20 March 2015, with a partial eclipse visible from the rest of Europe, West Asia, northern Arabia, North and West Africa, Iceland, Greenland and (briefly) Nova Scotia, Newfoundland and Labrador and parts of eastern Quebec. 

The path of the 20 March 2015 Solar Eclipse. The total eclipse will be visible along the central dark grey path. A partial eclipse will be visible from the shaded areas; in the lighters area the full eclipse will not be visible as it will have started before dawn (west) or will continue after sunset (east). The red lines are the Equator and the Greenwich Meridian. HM Nautical Almanac Office.

Eclipses are a product of the way the Earth, Moon and Sun move about one-another. The Moon orbits the Earth every 28 days, while the Earth orbits the Sun every 365 days, and because the two Sun and Moon appear roughly the same size when seen from Earth, it is quite possible for the Moon to block out the light of the Sun. At first sight this would seem likely to happen every month at the New Moon, when the Moon is on the same side of the Earth as the Sun, and therefore invisible (the Moon produced no light of its own, when we see the Moon we are seeing reflected sunlight, but this can only happen when we can see parts of the Moon illuminated by the Sun). 

The relative positions of the Sun, Moon and Earth during a Solar eclipse. Starry Night.

However the Moon does not orbit in quite the same plane as the Earth orbits the Sun, so the Eclipses only occur when the two orbital planes cross one-another; this typically happens two or three times a year, and always at the New Moon. During Total Eclipses the Moon entirely blocks the light of the Sun, however most Eclipses are Partial, the Moon only partially blocks the light of the Sun.

How the differing inclinations of the Earth and Moon's orbits prevent us having an eclipse every 28 days. Starry Skies.

Although the light of the Sun is reduced during an Eclipse, it is still extremely dangerous to look directly at the Sun.

Animation showing the shadow of the Moon at five minute intervals on Friday 20 March 2015. Andrew Sinclair/HM Nautical Almanac.

See also...

A partial Solar Eclipse will occur on Thursday 23 October 2014, visible from most of North America as well as parts of the Russian Far East. The eclipse will occur between 7.35 pm and 11.15 pm GMT, and be visible from most of Canada, the United States and Mexico, and parts of Guatemala, Belize, Cuba, the Bahamas and the Russian Far East.

A total Lunar Eclipse will occur on 8 October 2014, starting at about 9.15 am GMT. It will be visible across much of the Pacific, as well as eastern parts of the United States and Canada, northeastern Asia and eastern Australia. Part of the eclipse will be visible from remaining areas of the Americas as well as the rest of Australia most of Asia, although in these areas the Moon will either rise part way through the eclipse, or set before it is complete.

An Annular Eclipse will occur on Tuesday 29 April 2014, starting at about 3.52 am GMT. It will be visible from Australia, much of Antarctica and the southern Indian Ocean, eastern Java and the islands of the Bali, Flores and Savu Seas, though a full Annular Eclipse will only be visible from a small area of Antarctica.

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