Tonight’s Super Blue Moon: Last One Until 2037

Wednesday night will offer a special delight for astronomy enthusiasts as they will have the opportunity to witness a rare occurrence known as the “super blue Moon,” which will not be visible again for over ten years.

Supermoons occur when the Moon passes through perigee, or the point that brings it closest to Earth during its elliptical orbit. This makes it appear about 14 percent larger than when it is at its farthest point, and slightly brighter.

According to NASA, a full moon is defined by the exact moment they are opposite the Sun, which happens at 9:36 p.m. ET on Aug. 30 (0136 GMT Thursday).

Hosted by Italian astronomer Gianluca Masi, the Virtual Telescope Project will host a YouTube live stream starting at 0336 GMT, as it will be located on the Roman horizon.

Despite the description, it’s not actually blue: the term “blue moon” simply refers to when we see a full moon twice a month. This is because lunar cycles are slightly shorter at 29.5 days than calendar months, which are 30 or 31 days long, so it is possible for one to occur at the beginning of the month and the other right at the end.

The last super blue moon occurred in December 2009, and the next one appeared in quick succession: in January and March 2037.

The origin of the English expression “once in a blue moon” is now understood to mean something very rare, and goes back hundreds of years. In Elizabethan times “he claimed the Moon was blue” could be said of a person who made strange or apparently absurd claims.

However, it is possible for the Moon to take on a blue hue under the right conditions. This may be due to smoke or dust particles in the atmosphere scattering the red wavelengths of life, as was the case with the Krakatoa eruption in Indonesia in 1883.

According to Sky & Telescope magazine, dust from the event “turned Sunsets green and the Moon blue around the world for the better part of two years.” A more recent example may have occurred after the Chinchaga Firestorm of the 1950s, a huge fire that consumed Canada’s northern boreal forests.

The planet Saturn, which is just days away from making its closest and brightest approach to Earth this year, also appears near the Moon.

Wednesday’s full moon coincides with the Hindu festival of “Raksha Bandha,” or Rakhi, which celebrates the bond between siblings. Traditionally, siblings tie a rakhi bracelet around the wrist of their brother, who gives a gift in return.

It also coincides with the month of Elul in the Hebrew calendar, a time to seek and give forgiveness to others and start and end letters wishing the recipient a good year.

“As usual, wearing the appropriate festive celestial outfit is encouraged in honor of the full moon. Take care of your siblings, let go of grudges and here’s wishing you a happy new year!” said a NASA message.

While the super blue Moon makes for great photos, its stronger pull will also raise tides, which could worsen coastal flooding from Hurricane Idalia as it sweeps through Florida.