‘It’s always a good time to look at the moon,’ especially tonight’s super blue moon

If ever there was a perfect time for Elvis Presley’s 1954 cover of “Blue Moon,” it’s tonight.

“Imagine being on a tropical island, with your lover or friends, a campfire, this song playing, the sound of the ocean and a blue moon,” said a comment on the YouTube track featuring the King’s version of the 1934 song by Richard Rogers and Lorenz Hart.

There’s no imagination needed if you’re on any of the tropical Hawaiian Islands. The one and only blue moon of 2023 rises tonight. The moon will be the second full moon of August and the third supermoon of the year, making it a super blue moon.

It also will be the biggest and brightest supermoon of the year. The final supermoon of 2023 will be on Sept. 29. 

Moonrise is at 6:09 p.m. in Kona and 6:51 p.m. in Hilo on the Big Island. Elsewhere in the state, the super blue moon will rise at 6:13 p.m. in Kahului on Maui, 6:19 p.m. in Honolulu and 6:27 p.m. in Līhuʻe on Kaua‘i.

“When two full moons occur in the same month, the second full moon is often called a ‘blue moon,'” according to ‘Imiloa Astronomy Center’s August 2023 “Sky Watch.” “As this event is somewhat rare, it originated the idiom ‘once in a blue moon.'”

Supermoons happen three or four times a year. According to NASA, they occur when the moon is full and at or near its closest point to Earth, appearing especially large and bright in the sky.

Tonight’s super blue moon will be about 222,043 miles from Earth, or about 7% closer than usual compared to the average of 238,855 miles away — or about 30 Earths — and more than 100 miles closer than the Aug. 1 supermoon.

“It might be hard to detect a supermoon visually, but it does have an effect on Earth,” according to NASA. “Because the moon is in its closest approach to Earth, it can cause higher tides than usual.”

The space agency says about a quarter of all full moons are considered to be supermoons. However, only 3% of full moons are blue moons, which occur about two and three years apart. The next blue moon will happen on May 31, 2026.

It’s considerably less frequent that the two coincide, making tonight’s super blue moon that much more special.

NASA says super blue moons happen on average about every 10 years, sometimes even 20 years apart. The next super blue moons after tonight won’t occur for another nearly 14 years, in January and March of 2037.

Despite their name, blue moons do not appear blue. That doesn’t mean the moon can’t take on a bluish color from time to time.

“On past occasions, usually after vast forest fires or major volcanic eruptions, the moon has reportedly taken on a bluish or lavender hue,” according to the Farmers’ Almanac.

When dust and ash particles of roughly one micron, or 0.00004 of an inch, in size are propelled high into our atmosphere, they scatter yellow and red light, making the moon appear to have a faint bluish tinge, though it never actually changes color.

Ash from an eruption of Indonesia’s Krakatoa volcano in 1883 caused full moons to take on a blue color. Blue-tinted moons persisted for years after the eruption, according to a NASA feature in 2004. People also saw lavender suns.

“The ash caused ‘such vivid red sunsets that fire engines were called out in New York, Poughkeepsie and New Haven to quench the apparent conflagration,’ according to volcanologist Scott Rowland at the University of Hawai‘i,” the space agency’s article said.

The 1980 eruption of Mt. Saint Helens in Washington state also caused blue-colored full moons.

Neither eruption, however, corresponded with astronomical blue moons.

The weather tonight in Hilo might not cooperate for skywatchers to take in the rare super blue moon, with the National Weather Service forecast office in Honolulu calling for mostly cloudy skies and scattered showers. Pāhoa could be out, too, as skies are forecast to be mostly cloudy with showers likely after midnight. Waimea could see some isolated showers before midnight, but otherwise will be partly cloudy.

It will be mostly clear in Kona and Nāʻālehu overnight, and perhaps the best viewing will be atop Maunakea, where the Maunakea Observatories forecast shows the summit is expected to be predominantly clear.

Elsewhere in the islands, Kahului will be mostly clear, Honolulu will likely have a few clouds and Līhuʻe is expected to have mostly cloudy conditions with scattered showers.

Is the super blue moon worth checking out?

“Hey, it’s always a good time to look at the moon!” says NASA.