Look up in the night sky Sunday through Tuesday, August 18–20 to enjoy a rare blue supermoon this week. Reaching peak fullness at 2:26 p.m. ET on Monday, August 19, it’s the first full supermoon on 2024’s full moon calendar—and the second year in a row that we’ve enjoyed a blue supermoon in August.Blue moons happen every two to three years, but a blue moon that is also “super”? (That is, a full moon that is at or near its closest point to Earth in its orbit?) That is less common. So how is it possible for one to occur in the same month for two consecutive years? It all comes down to how you define a blue moon, and there are two ways: The newer definition of a blue moon is the second full moon to occur within one calendar month. By this definition, the second full moon in August 2023 was a blue moon. This use of the term is more well-known today—and also more easily grasped in terms of our modern calendar. But, says the Royal Museums Greenwich, this definition originated “as a mistake, made in the 1940s and perpetuated by radio shows and the Trivial Pursuit board game through the 1980s.”The full moon we view in August 2024 will be “blue” according to the original definition: “the third full moon in an astronomical season containing four full moons,” according to RMG. Astronomical seasons are set by the solar equinoxes and solstices. In this case, summer began on the solstice on June 20 this year and will end with the autumn equinox on Sunday, September 22. Typically, there are only three full moons in the three-month time frame of an astronomical season, but this summer, there are four, including the full moons on June 21, July 21, August 19, and September 17, making August’s full moon blue. Notice that neither definition has anything to do with the moon actually appearing blue in color. Such an event is much, much rarer still, most accurately fitting the idiom “once in a blue moon.” The moon on very rare occasions can take on a blue cast due to particles in the atmosphere from a volcanic eruption or even a wildfire. For example, 141 years ago, the massive, deadly eruption of the Indonesian volcano Krakatoa in August 1883 reportedly made the moon appear blue. Otherwise, if the moon looks blue in a photo, it’s due to a filter or editing. As for the “super” part of the August 2024 blue supermoon, that can be a bit misleading. It will appear a little brighter and larger due to being with 90 percent of its closest point to Earth in its orbit—361,970km to be precise, according to astronomer Fred Espenak’s site, Astropixels.com. However, most experts agree the difference is hard to perceive and that the moon illusion (when the moon looks larger because it’s near the horizon) has a greater effect on our perception. August 19 marks the first in this year’s series of four consecutive full supermoons, but it’s not the closest—that distinction goes to October’s Harvest Moon. Read on for full moon calendar dates for the rest of 2024, so you’ll always know when the next full moon.What are the dates the full moon in 2024? Check the full moon calendar!The traditional moon names included in our full moon calendar below come from The Old Farmer’s Almanac and, according to the popular reference guide, were passed down for generations in Native American tribes (some naming customs from European American settlers are woven in too). These special names, based on natural events, helped users keep track of the seasons, though the same moon often went by other monikers in different regions. Full moon calendar dates for the rest of 2024August 19, 2024 (2:26 p.m. ET) Sturgeon MoonJudging by its name, the fishing is good during this moon—especially for sturgeon, once abundant this time of year in the Great Lakes and other northern bodies of water. September 17, 2024 (10:34 p.m. ET) Harvest MoonThe full moon closest to the fall equinox, the Harvest Moon may occur occasionally in October. It is during the helpful light of this moon that corn is often harvested. October 17, 2024 (7:26 a.m. ET) Hunter’s MoonThis moon marked a crucial time for hunters to store up meat before winter. The Hunter's Moon also was considered a feast day for Native Americans and many Western Europeans. November 15, 2024 (4:28 p.m. ET) Beaver MoonTrapping beavers, prized for their warm fur, were popular during this lunation activity.December 15, 2024 (4:02 a.m. ET) Cold MoonThis moon marks the start of the year's coldest months. How does the full moon affect us?The nearest celestial body to Earth and the only one humans have literally set foot on, the moon has a tremendous influence on our world. But its impact seems even more profound when the moon appears fully lit, which happens when the moon is opposite the sun in its rotation around Earth, with the entire sunlit side visible. For example, full moon tides are more intense than tides occurring during some other moon phases. The alignment of the sun, moon, and Earth creates extremely low, low tides and super-high high tides, both commonly known as spring tides. There also have been studies that have shown full moons can affect everything from sleep to cardiovascular conditions and even bipolar disorder symptoms.