As the eclipse plunges the world into darkness on Friday, two other 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, The Independent reports.
The spring equinox is the time of year when day and night are of equal duration. It marks the in-between point of the year’s shortest and longest days.
The solar eclipse is a phenomenon that happens when the sun and the moon line up, so that the moon obscures the look of the sun. While the eclipse won’t be effected by the other two events, the three events are rare even when occurring individually.
There are usually between three and six supermoons per year. There are six supposedly happening in 2015, two of which have already occurred. The next will take place on March 20, the day of the eclipse. The rest come in August, September and October.
Eclipses can only happen at a new moon, when the moon appears to be entirely shadowed, according to The Independent.
The incredible images of supermoons you normally see can only happen when the moon is full, though.
As a result, only the last three supermoons of this year will be visible — because the moon is new rather than full on March 20, it won’t be seen. However, it will be gliding past us closer than ever, and its shadow will be visible as it blocks out the sun on Friday morning.
The equinox is also happening on March 20. While it won’t have a discernible impact on how the solar eclipse looks, it’s certainly a part of a rare collision of the three unusual celestial events.
On March 20, the Earth’s axis will be perpendicular to the sun’s rays, which only happens twice a year at each of the two equinoxes. After that, earth will continue moving, making for longer days in the northern hemisphere.
Because of the symbolism, the equinox has long been celebrated as a new chapter or renewal. It’s also linked to Easter and Passover, The Independent reports.
The equinox will happen at the same time as a solar eclipse in 2053 and 2072, though it doesn’t always appear as close together as that.
So how can you see Friday’s eclipse?
“The dark umbral shadow cone of the moon will trace a curved path primarily over the North Atlantic and Arctic Oceans, beginning off the southern tip of Greenland and then winding its way counterclockwise to the northeast, passing between Iceland and the United Kingdom.”
The eclipse is scheduled to start just after 3:30 a.m. (EDT) Friday. EclipseWise has a map of eclipse times in the Atlantic so you can pinpoint when and where to look out.
If you don’t have the chance to see the solar eclipse in person, you can catch it live online. The online Slooh Community Observatory will broadcast live views of the solar eclipse through its website Slooh.com, beginning at 4:30 a.m. (EDT).
WARNING: If you’re in the eclipse zone, be very careful. Never look directly at the sun without special safety equipment; permanent and serious eye damage could result. You can build a pinhole camera or solar projector with binoculars to safely observe the eclipse.