Tonight, August 30, 2023, stargazers will witness a rare celestial event: a blue supermoon. This phenomenon occurs when a full moon coincides with the moon’s closest approach to Earth in its orbit, making it appear larger and brighter than usual. This particular event is even more special because it is also a “blue moon”, which refers to the second full moon within a single calendar month. The last “blue supermoon” occurred in December 2009, and the next one won’t happen until January 2037.
Why is it called a blue moon?
The term “blue moon” has nothing to do with the actual color of the moon. It refers to the occurrence of an additional full moon within a specific time frame. There are two types of blue moons:
- Seasonal Blue Moon: The third full moon in a season that has four full moons.
- Monthly Blue Moon: The second full moon within a single calendar month.
In this case, the blue moon on August 30, 2023, is a monthly blue moon, as it is the second full moon in August. Blue moons occur once every two or three years on average.
Why is it called a supermoon?
A supermoon occurs when a full moon or a new moon nearly coincides with the moon’s perigee, which is the closest point in its elliptical orbit around Earth. This results in a slightly larger-than-usual apparent size of the lunar disk as viewed from Earth. Supermoons appear about 14% larger and 30% brighter than regular full moons.
How rare is this event?
While blue moons occur once every two or three years on average, a blue moon that is also a supermoon is even rarer. The average time between super blue moons is 10 years, and they can be separated by as much as 20 years. As mentioned earlier, the next blue supermoon won’t occur until 2037.
To witness this rare celestial event, you can watch the blue supermoon rise tonight, August 30, 2023. The moon will officially turn full at 9:36 PM ET. You can use a moonrise calculator to find out when the blue supermoon will be visible in your area. For a more detailed view of the moon’s texture, NASA recommends using binoculars or a telescope.
