As the eclipse plunges the UK and other places into darkness this Friday, two other rare if less spectacular celestial events will be taking place, too: a Supermoon and the Spring equinox.
A Supermoon, or perigee moon, happens when the full or new moon does its closest fly-by of the Earth, making it look bigger than it normally does. And the spring equinox refers to the time of the year when the day and night are of equal duration, mid-way between the longest and shortest days.
The solar eclipse refers to a phenomenon where the sun and moon line up, so that the latter obscures the former. And while it won’t be affected by the two other events, it is rare that the three events happen even individually.
Most of the time, there are between three and six Supermoons a year. There is set to be six in 2015, two of which have already happened. The next will take place on March 20, the day of the eclipse, and the others will come in August, September and October.
Full article: Solar eclipse, Supermoon, Spring equinox: Friday will see three rare celestial events (The Independent)