August continues to be an exciting month for sky-gazers. Closely following the peak of the Perseid meteor shower last week, the first of the year’s four consecutive supermoons is set to rise on August 19. The rare cosmic combination of a supermoon and blue moon peaks at 2:26 p.m. ET Monday.
The last time this lunar event occurred was August 2023, and the next super blue moons are projected for January and March of 2037. Approximately one-quarter of all full moons are supermoons, while a mere 3% of full moons are blue moons.
So-called supermoons appear as the biggest and brightest lunar events of the year. The moon’s orbit around Earth is not a perfect circle but an elliptical path. Scientists refer to the moon’s nearest point to Earth — an average distance of about 226,000 miles (363,300 kilometers) — along its 27-day journey as the satellite’s perigee.
There are varied definitions for supermoons. However, a full moon within 90% of perigee is often described as a supermoon.
When the moon is closest to Earth in its orbit, it can appear up to 14% larger and 30% brighter than when it’s at its farthest point from the planet, known as apogee, about 251,000 miles (405,500 kilometers) from Earth.
While this perceived size increase might be subtle, a supermoon is noticeably brighter than other full moons throughout the year. It may be challenging to see the difference, but a supermoon significantly impacts Earth, leading to higher-than-normal tides due to its proximity.
Supermoons are observable to the naked eye and do not require a particular location for viewing. Throughout the night, the moon will rise higher until just before sunrise.
The joy of these full moons is that if cloud coverage obscures visibility, you can look any night before or after the full moon peaks.
Supermoons are 30% brighter than average full moons, making them more easily detectable.
What are blue moons? Despite the name dating from 1528, the moon will not appear blue in color.
As with supermoons, there are varying definitions for blue moons — monthly and seasonal.
On average, we have one full moon, per month. Sometimes we might have another full moon again at the very end of the month. So sometimes that’s called a blue moon.
A seasonal blue moon is often defined as the third full moon of an astronomical season with four full moons.
In the 1930s, the Maine Farmer’s Almanac started applying names corresponding to events in nature for the full moons. These names have since become widely used and recognized.
Keep an eye out for Jupiter and Mars while peering at the moon.
Last week, the two planets were aligned in conjunction, reaching their closest proximity to each other from Earth’s viewpoint since 2018. Jupiter and Mars will likely remain fairly close to one another in the sky during the supermoon’s peak.
And in the next month or so, anticipate a brightening event, known as a nova, that will occur in the Milky Way’s Corona Borealis, or Northern Crown constellation. Astronomers expect T Coronae Borealis to explosively burst as a binary system of a dead white dwarf star and an aging red giant star violently collapse.
The remaining supermoons of 2024 will occur on September 18, October 17, and November 15.
The September supermoon will also be a partial lunar eclipse, meaning Earth will cast its shadow over part of the moon.
The fullest, largest moon of the year will rise in October.
