Blue supermoon can be seen this Wednesday – 08/30/2023 – Science

The second and last supermoon of this year can be seen from all regions of the planet on Wednesday night (30). With good visibility, it already appears in the sky from sunset. The best time for viewing, considering the Brasília time zone, is at 22:35.

The first occurrence of the event in 2023 was on August 1st. The phenomenon is characterized by the greater visibility of the satellite during perigee, the point of its orbit closest to Earth. To observers, it appears 14% larger and 30% brighter than the average Moon.

Although called a blue supermoon, the phenomenon has nothing to do with color. According to a note from the astronomy center at the Federal University of Minas Gerais, the classification refers to the expression in English “once in a blue moon”, whose translation is “very rarely”. In this case, it concerns the second full moon within the same month, as is the case now.

“What is rare is the fact that it is the second full moon of the month. It happened in 2009, and the next one only in 2032”, says Josina Nascimento, an astronomer at the National Observatory, about the calendar coincidence.

As the phenomenon does not have a formal definition regulated by the International Astronomical Union, institutions can use their own criteria to say whether or not a supermoon happens. In the case of the National Observatory, this calculation considers the position of the Moon at least 90% at perigee, adopted by astrologer Richard Nolle in 1979. Therefore, an event in July of this year could not be considered a supermoon, according to Nascimento.

Anyone who wants to see the phenomenon just needs to hope for good visibility from a cloudless sky. In the capital of São Paulo, forecast by the City Hall’s Center for Climate Emergency Management (CGE) indicates that the day starts and ends cloudy, although there is a decrease in cloudiness throughout the afternoon.

According to Nascimento, at any time of the night it will be possible to see the Moon, from sunset on Wednesday until dawn on Thursday (31). “When the satellite is close to the horizon, it will look even bigger. And the luminosity interacts with the particles that are in the air, so we see the moon reddish or yellowish. If the person has the opportunity to see it at these times, great. But throughout at night there will be a supermoon.”

The next occurrence of three supermoons in one year should be in 2028, according to the astronomer. But she has a caveat: the calculation takes into account the occurrence of full supermoons according to Richard Nolle’s definition.

Following this criterion, 2026 and 2027 will have only one supermoon each. According to the National Observatory, since the year 2000, the day on which the supermoon has come closest to Earth has been on November 14, 2016, when it was 356,509 kilometers away from the planet. The prediction is that such a close pass will occur again on December 24, 2026, when the Moon will be 356,650 kilometers from Earth.