After spectacular views on January 21 and February 19, the third and final supermoon of the year is happening tonight, March 20, on the date of the spring equinox. Serious and casual stargazers alike won’t want to miss it.
According to NASA, a supermoon happens when the moon is both in its full phase and at its perigee, at the point in its elliptical orbit where it’s closest to earth, or about 226,000 miles away on average. Astronomers call this phenomenon a perigean full moon, but it’s been known more informally as a supermoon since 1979.
By comparison, at its apogee, when the moon is furthest away, it’s about 253,000 miles away on average.
Technically, the perigree will happen at 3:47 p.m. Eastern time today and the moon won’t turn full until 9:43 p.m., but that doesn’t mean it won’t be worth staring up at the sky with your kids.
Tonight’s lunar display isn’t just a supermoon, either. It’s also what’s known as a worm moon, the name given to the March full moon that coincides with the start of spring in the Northern Hemisphere, when the worms start emerging from the frozen ground.
You don’t need any equipment to enjoy the supermoon, just your eyes, your kids, and, depending on the weather in your area, a cup of hot cocoa.
If bad weather prevents you from enjoying the supermoon, the next best thing is probably the Virtual Telescope Project, a collection of several telescopes in Italy that will live stream a great view of the night sky.
If you miss it tonight, you’ll have to wait a while to see a supermoon again. There will be four next year, with the first taking place on February 9.