When to see 4 full supermoons, including rare blue moon in 2024
Stargazers, mark your calendars: 2024′s night-sky highlights include four full supermoons in a row, plus a rare blue moon.
First, what are all these different types of moons, exactly?
The full moon is known as a supermoon when it becomes fully illuminated around the same time that it reaches perigee, or its closest point to Earth on its monthly orbit. This synchronism happens just a few times each year, according to EarthSky.org, and can cause the moon to appear quite a bit brighter in the sky.
There are also several “new supermoons” each year, occurring when the moon is in its new phase, or 0% illumination. These don’t receive the same kind of attention that full-moon supermoons do because new moons happen when the moon’s shadow side faces Earth, making them invisible to us.
Blue moons are even more rare than supermoons, but defining them can be a bit murky.
Since the late 20th century, the term “blue moon” has been used to describe the second full moon landing within one calendar month.
But more traditionally, the term blue moon applied only when an extra full moon fell within a single season — meaning spring, summer, fall or winter, as defined as the time between a solstice and an equinox. In the case of these so-called seasonal blue moons, the blue moon is actually the third of four full moons in one season (not the extra fourth moon).
So when are all these fantastic full moons happening this year?
In 2024, we’ll have one of those special seasonal blue moons on Aug. 19, according to EarthSky. It will be the last seasonal blue moon until May 20, 2027.
The Aug. 19 blue moon will just so happen to kick off 2024′s string of four supermoons, too. The ensuring full supermoons will occur on Sept. 18, Oct. 17, and Nov. 15.
If you love skywatching, you can mark these dates in your 2024 calendar so you don’t miss the chance to look for the extra-bright, beautiful moon on these days.