A supermoon happens when the full moon coincides with the moon’s closest approach to Earth in its orbit. Supermoons make the moon appear a little brighter and closer than normal, although the difference is hard to spot with the naked eye. The term “supermoon” has only been used in the past 40 years, but it received a slew of attention in late 2016 when three supermoons occurred in a row. The supermoon of November 2016 was also the closest supermoon in 69 years, although a closer supermoon will rise in the 2030s. The moon’s orbit around the Earth is not a perfect circle. It has an average distance of 238,000 miles (382,900 km) from Earth, but its apogee and perigee — the closest and farthest approaches from Earth — change every lunar month.