On Tuesday evening, stargazers in North America, South America, Europe, and Africa will be treated to three celestial events taking place at the same time: the harvest moon, a blood moon, and a supermoon. All three occurring simultaneously are “quite rare,” Teresa Monsue, an astrophysicist at NASA’s Goddard Space Flight Center, told NPR. [time-brightcove not-tgx=”true”] Here’s what to know about the celestial trifecta and how to watch it in the U.S. Read More: These Are All the Different Types of Eclipses What is a harvest moon? The harvest moon appears near the autumn equinox.