There are so many things to do in Chicago, but, for astronomy enthusiasts, this one is pretty exciting! We are in for a treat this week when yet another supermoon takes to the skies for the second time in one month.
Having already experienced the Sturgeon Moon on the first day of the month, a rare and captivating Blue Moon will grace the skies above Chicago this week, outsizing and outshining the supermoon that took place in early August.
What is a supermoon?
According to NASA, a supermoon happens when the moon reaches its closest point to Earth, coinciding with its full phase, known as ‘perigee’ in astronomical terms.
Astrologer Richard Nolle, credited with coining the term, defines a full moon or new moon as a supermoon if it occurs when the moon is within 90 percent of its nearest distance to Earth. This results in the moon appearing significantly brighter and larger than its regular size.
When at its perigee, the moon can appear up to 15% larger than it does at its farthest point from Earth, known as ‘the apogee’), and about 6-7% larger than an average full moon. Supermoons happen about 3 to 4 times each year.
How often does Earth experience a Blue Moon?
There are two definitions for a Blue Moon—a seasonal Blue Moon and a monthly Blue Moon. The former is the third full moon of an astronomical season that has four full moons while the latter is the occurrence of a second full moon in the same month.
Moon phases span around 29.5 days and given that most months have 30 or 31 days we are nearly always treated to 12 full moons a year and 1 full moon per month.
As 12 lunar cycles take 354 days those extra days build up and eventually add a 13th full moon within a calendar year every 2-3 years.
Despite its name a Blue Moon doesn’t actually change color unless a lunar eclipse happens at the same time.
When can you see the Blue Supermoon in Chicago?
The last Blue Moon was on August 22, 2021, and this year’s will be on August 30, 2023.
The Blue Moon will reach its highest point at approximately 8:35 pm on Wednesday, August 30, 2023, according to Time and Date.
That day the moon will rise at 7:42 pm and set at 6:43 am on Thursday, August 31st.
For those wanting to make an event of it, or photographers hoping to catch the clearest shot, it is best to head as far away as you can from artificial lighting by finding a secluded area that isn’t affected by light pollution from city lights.
Check out this light pollution map to find a dark sky near you!
[Featured image from Shutterstock]