May ends with Blue Moon and micromoon on the same date

The month of May 2026 will come to an end with two astronomical phenomena. Next Sunday (31), the so-called Blue Moon will take place, the name given to the second Full Moon recorded in the same month. There is, however, no change in the color of the Moon. On the same date, Earth's natural satellite will be at the furthest point from the planet, which makes it appear a little smaller and less bright in the sky, being called a micromoon. To complete the event, the Moon will appear close to the star Antares.

"The occurrence of two Full Moons in the same month is possible because the interval between two Full Moons lasts, on average, around 29.5 days, while calendar months have between 28 and 31 days. Thus, when a Full Moon occurs on the 1st or 2nd of the month, there is a possibility of the cycle being completed before the month ends. On average, we have a Blue Moon every two or three years", explains astronomer Dr. Gabriel Hickel, professor at the Federal University of Itajubá (UNIFEI) and partner of the National Observatory (ON/MCTI) in the program "O Céu em Sua Casa".

Micromoon

As the lunar orbit around the Earth is an ellipse, the distance between the two bodies varies periodically. There is the point of closest approach (perigee) and the point of greatest distance (apogee). Therefore, when the full phase coincides with the apogee, we have the so-called micro full moon. If it occurs at perigee, it is a super full moon.

"On May 31st, we will have the furthest Full Moon of 2026, 406,135 km from Earth. It will be the smallest and least bright Full Moon of the year. However, people will hardly notice the difference. The point is that the human brain works on the basis of instantaneous comparison and, without seeing a supermoon and a micromoon simultaneously, there is no way to compare. Visually, the satellite will appear about 12% smaller and 25% smaller brighter than a supermoon, but in practice, people will observe a normal Full Moon, for lack of comparison. However, it is, in fact, the micromoon of 2026", highlights Hickel.

Estrela Antares

The Full Moon on May 31st will gain a special touch with the apparent proximity of Antares, the brightest star in the constellation Scorpio, with its characteristic reddish glow, contrasting with the silver of the Moon.

Note

The ideal observation window begins at moonrise on Saturday (30). Every Full Moon rises when the Sun sets and stays in the sky throughout the night, setting the next day at the time the Sun rises. The peak of the approach between the Moon and Antares will occur at the moon's sunset, late in the morning.

"When the Moon rises and sets, the effect of the "lunar illusion" occurs, which causes the human brain to interpret that our satellite appears larger than it is. However, these are also the moments for better photos, in composition with the landscape. It is recommended to look for locations with an open horizon and interesting elements for the composition of the photos. To record the moment with your cell phone, experts advise adjusting the camera's exposure manually to prevent the excessive brightness of the Moon from erasing the details of the image", he suggests Hickel.

Origin of the name Blue Moon

Unlike what the term Blue Moon suggests, the Moon will not have a bluish hue. The term Blue Moon was imported from the United States, where it appeared in British literary works from the beginning of the 19th century, which poetically described the rare phenomenon of observing the Moon with a bluish color, due to the presence of particles from volcanic eruptions in the upper atmosphere. For reasons that are not very clear, farmers of British origin began to designate the 13th Full Moon of a year as a Blue Moon.

Subsequently, due to an error of interpretation, the famous Astronomy magazine Sky and Telescope associated, in 1946, the term Blue Moon with the 2nd Full Moon of a month in the Western (Gregorian) calendar. From the 1980s onwards, the term became popular throughout the world.

The Moon only acquires a real bluish color in extreme atmospheric situations, such as after large volcanic eruptions or large-scale forest fires, which release particles into the atmosphere capable of filtering red light more than other colors. Thus, the Moon may appear to have a blue or blue-green color, regardless of the phase it is in.

Source: Antena 1