Californians were treated to a celestial spectacle this weekend as a rare blue moon rose dramatically over the Golden State, painting the sky in mesmerizing orange hues. A breathtaking time-lapse captured by many moon gazers, including Shreenivasan Manievannan on Instagram, shows the moon climbing above San Francisco's Bay Area between Saturday evening, May 30, and Sunday morning, May 31. But despite its name, the blue moon wasn’t actually blue. The term refers to the second full moon in a single calendar month — a relatively uncommon event that occurs roughly every two and a half to three years.