The full moon illuminated an owl-shaped finial atop a house in Hede-Bazouges, a suburb of Rennes, western France, on October 29, 2023, just a few days before Halloween.
This week marks the occurrence of the largest full moon of 2024. The moon will officially reach its full phase on Thursday, October 17, at 7:26 a.m. EDT (11:26 GMT). Earlier, on Wednesday night at 8:48 p.m. EDT, the moon will also be at perigee, its closest approach to Earth, which will be just 221,938 miles (357,174 km) away.
These two events will create a “supermoon,” which will be 14% brighter than the average full moon, leading to unusually high and low tides later this week. Dr. Fred Espenak, a retired NASA astrophysicist, describes a supermoon as a full moon that occurs when the moon is within 90% of its closest distance to Earth. He has documented all supermoons of the 21st century and notes that there are four supermoons scheduled for 2024, notably in August, September, October, and November.
The full moon of October will occur at 7:26 a.m. EDT or 11:26 GMT on Thursday, October 17. On the contrary, on April 13, 2025, the full moon will coincide closely with apogee, when the moon is furthest from Earth, making it appear 14% smaller.
Traditionally, Native Americans referred to the October full moon as the Hunter’s Moon, a time when hunting became prominent due to falling leaves and fattened game.
During the full and new moons, “spring” tides occur, which are caused by the alignment of the moon and sun with the Earth, resulting in stronger tidal effects. Conversely, “neap” tides occur during the first and last quarters of the moon, leading to weaker tides.
Despite the high tides associated with the full moon, the peak tides actually occur a couple of days later in some coastal areas. For instance, the highest tide in Boston Harbor is predicted for 12:11 p.m. EDT on Friday, nearly two days after the perigee moon.
The effect of the moon’s proximity is often not noticeable unless viewed on the horizon, where it can appear strikingly large due to the “moon illusion.” As the perigee moon rises in the east around sunset or sets in the west at sunrise, it can indeed look so vast that it seems almost within reach.
For those wanting to experience the full effect of the supermoon, it’s best to observe it on Wednesday night when it will be nearing full and closest to Earth.