Outdoing the Blue Moon

(Illustration by Sarah G.)

Next Friday, August 31, it’s the Blue Moon. That term was the result of a misunderstanding in a 1940s astronomy magazine. But it went viral, until nowadays the second Full Moon in the same calendar month is widely called a Blue Moon.

The expression suggests great rarity. In reality, since the Moon’s period of phases is 29½ days, while months usually have 30 or 31 days, it’s obvious that if a Full Moon lands on the first day of any month except February, it will repeat at the end. Even a Full Moon falling on the second day will often do the job. Turns out that Blue Moons happen every 30 months on average: two-and-a-half years – not so very rare.

But if you want rare, the sky can oblige. We just experienced a transit of Venus, which won’t recur until 2117. What other noteworthy or visually stunning events are rare?


Start with the coast-to-coast total solar eclipse of August 21, 2017: the first solar totality in the mainland US in 38 years. The path of blackness will sweep over Jackson, Wyoming and Nashville, Tennessee. Then, just seven years later, a stunning solar totality will venture much closer to us. On April 8, 2024, a ribbon of night, the stars out at noon, with geysers of pink nuclear flames visibly shooting from the solar edge, will cross upstate New York and New England. We haven’t had a total solar eclipse since January 24, 1925, but this one will be seen from as nearby to us as Rochester and Burlington.

Five years later, the asteroid Apophis barely misses us, and visibly glides across the sky on April 13, 2029, closer than our TV satellites. The longest totality in US history arrives on August 12, 2045: six full minutes of darkness. We’ll get an extremely close Mars encounter in 2050 to rival the one in 2003. Then Comet Halley will pay us an unusually close visit in 2061. It will be nothing like its ho-hum approach of 1985/86, when Earth was on the wrong side of the Sun when the comet went by.

Then will come two US solar totalities in a single year, and the second one, on May 1, 2079, will be seen from right here, throughout the mid-Hudson Valley and Catskills. It may seem far in the future; but, since our region only gets a solar totality every 360 years on average, it’s really not such a long wait. Keep working out at the gym.

Finally, we may get a “meteor storm” here in 2099. That should even outdo the great display that our region saw, under perfectly clear and moonless skies, in the hours before dawn on November 18, 2001: the most fantastic meteors of our lives to date. I hope that you’re writing all this down.

Some additional super-spectacles like animated, brilliant, all-sky Northern Lights exhibits and CGI-worthy “Great Comets” can’t be predicted much in advance, but will definitely happen too. Hudson Valley auroras should appear soon, with a couple during 2013 and 2014, since solar max is expected this coming spring. And a Great Comet to rival 1997’s Hale-Bopp arrives every 15 to 20 years on average, so we’re now “due.”

Once in a Blue Moon? Stick around and you’ll see the best rare spectacles right from your own lawn. Friday’s Full Moon doesn’t even count.