This month of August will leave us with an unusual doublet of full moons. The eighth month of 2023 began with the Sturgeon supermoon and now comes to an end with the superblue moon. That the same month offers two full moons is a phenomenon that only occurs every two and a half years, but that it is also a supermoon is an even more exceptional event.

The name blue moon is used to indicate the second full moon of the same month (or the fourth full moon that occurs in a season). The origin of the term is in an English expression (blue moon) from the 16th century that refers to something that never or rarely happens. Of course, the denomination has nothing to do with the color of the Moon.

“Since the year has 12 months (a total of 365 or 366 days), it contains about 12.4 lunations. It turns out, then, that, depending on the fit of the lunar cycles in the calendar, there can be years in which they happen not 12, if not 13 full moons; this is the case of 2023”, explains Rafael Bachiller, director of the National Astronomical Observatory (National Geographic Institute).

On the other hand, the term supermoon is used when the satellite is in the closest position to Earth (perigee), at about 357,344 kilometers. At that time, the diameter of the Moon can be seen 14% larger than the apparent size of the Moon at its apogee.

Thus, the full moon of August 31, 2023 is a super blue moon, since it is the second full moon of the same month and also takes place in the perigee.

Located in the constellation of Pisces, the super blue moon rises this Thursday from 9:30 p.m., while the apogee takes place at 2:36 a.m. (peninsular time) in the morning from August 31 to September 1.

To see two supermoons in the same month again, we have to wait until 2026, so this is a good time to enjoy this astronomical phenomenon.

To see the full moon it is not necessary to have a telescope, since our own eyes are enough to contemplate its magical lighting, even being able to distinguish certain features of its face. Of course, the use of binoculars allows you to appreciate more details of its surface.

The most important thing will be to situate ourselves at a high point, without obstacles and where there is little light pollution.