August is almost done, but it still has a rare occasion in store for skywatchers: a second full moon. The blue moon is expected to rise at 6.17 p.m.
The full moon on Wednesday, Aug. 30, will be a spectacular one as well, combining a supermoon and a Blue Moon to form a “Super Blue Moon.” However, the moon will not appear exceptionally blue at this hour.
The name “Blue Moon” refers to either two moons happening in the same calendar month (as in this case) or the third full moon in a season with four full moons. A supermoon, on the other hand, is a full moon that happens when the moon’s orbit brings it closer to Earth, resulting in a somewhat larger and brighter look.
And if weather is poor in your area, no need to fret: You can watch the Super Blue Moon with a free livestream hosted by the Virtual Telescope Project.
The exact moment of the full moon is defined as the moment at which it is exactly opposite the sun. For the Super Blue Moon, this 180-degree separation from the sun with happen at around 21:36 EDT (0336 on Thursday, Aug. 31), according to NASA, and this is when it will be at its biggest and brightest.
Following the full moon on Wednesday, the moon will rise and set an hour later each night and the illuminated side of the moon will shrink or “wane.” This leads to the next new moon on Thursday, Sept. 14, at which time the moon will be completely dark and will rise and set with the sun, meaning it is completely absent from the night sky. The new moon will mark the beginning of the next 29.5-day lunar cycle. Roughly two weeks after this will be the next full moon, September’s Full Corn Moon. Falling on Sept. 29, this will be the fourth supermoon in 2023, and will also be the final supermoon of this year.
Supermoons happen because the moon’s orbit around Earth is an oval or an elliptical shape rather than being perfectly circular. As a result, there are times during the moon’s orbit when it is further away — at apogee — and times when it is closer — at perigee. The distance between Earth and the moon at perigee increases by around 14% compared to its distance at apogee, changing from around 253,000 miles (408,000 kilometers) away to around 220,000 miles (350,000 kilometers) away.
This 14% increase in proximity may sound substantial, but it doesn’t make much difference to how the moon appears to the untrained eye, though it is technically larger and brighter in the night sky.
