On Monday, you will be able to witness something in the night sky that isn’t seen often, but is a sight to see: a full moon on the night of the summer solstice. “Because the solstice is not on exactly the same day each year, it’s actually much rarer to get the full moon on a solstice,” Dr. Angela Speck, Professor of Astrophysics at the University of Missouri, says.
Just how rare? Well, that’s a numbers game. As Speck explains, we get a full moon every 29.5 days – so the precise day that the moon is full is constantly changing. If you add up the days, the total of 12 lunar phase cycles is only 354 days. Therefore, the cycle of the solstice full moon is about 19 years long. But because the solstice is not on exactly the same day each year (because of leap years), that causes the solstice full moon to be an infrequent occurrence.
For Monday night’s show in the sky, the “strawberry moon” (nicknamed for its hue and seasonal appearance) will be showing up late. The summer solstice is the longest day of the year — and at about 17 hours of daylight, the moon won’t have a lot of time to shine. “The moon won’t be visible until it rises — and it can’t right until the sun sets,” Speck says. “Because of the tilt of the earth at this time of the year, we will get a much later moonrise.”
When the moon does rise, it will be full and have a slightly amber-hue. The rise will be about two hours after the solstice — in the eight o’clock hour (8:41 p.m. Eastern Standard Time) along the East Coast.
Be prepared for a totally different experience next summer, when a complete total solar eclipse will cover the continental USA in August 2017. It will be the first total solar eclipse since 1979, and the first one to cross the continent from ocean to ocean since 1918.