Get ready for the ‘sturgeon supermoon’

The head of astronomy at the Adler Planetarium encourages Chicagoans to go outside Thursday night and look up to catch a “supermoon.”

“Go outside, go on your rooftop or look out your window, anywhere really, and check out the moon. It’s fun,” said Geza Gyuk, director of astronomy.

Supermoons appear slightly bigger and brighter than usual.

“What I tell people is that it’s not really that, ‘Oh, my goodness, it’s a supermoon, a once-in-a-lifetime event,’ ” Gyuk said. “What it is is a good time to take a moment to look at the moon. It’s something we don’t really pay attention to, but if we have the excuse of, ‘Hey, it’s a supermoon,’ then maybe it will make some people go and look and say, ‘Wow, that’s amazing.’ ”

“I’ll be hiking in the Rockies on Thursday. I’ll definitely be looking at the moon. Everyone in the world can.”

Gyuk said the supermoon does present a bit of a bummer to skywatchers hoping to view the Perseid meteor shower, a highly anticipated event that will be going on at the same time.

“It’s sort of actually too bad because when you have a bright moon, it sort of washes out the light of the meteor shower and makes it harder to see,” he said.

You might see one meteor streaking across the sky every five or 10 minutes in Chicago, versus one a minute in a dark sky, he said.

“So have a little patience,” he said. “Settle in and chat with a friend and occasionally you might be rewarded.”

A supermoon occurs when the moon’s orbit — which is not a perfect circle — brings it closer to Earth than usual.

The number of supermoons can vary, depending on who is making the call on a supermoon.

Different groups go by different measurements between the moon and Earth when it comes to declaring a full moon a supermoon.

Full moons, which appear about every 29 days, picked up popular monikers in the 20th century depending on the month, Gyuk said.

“August’s full moon was traditionally called the sturgeon moon because the giant sturgeon of the Great Lakes and Lake Champlain were most readily caught during this part of summer,” according to the Old Farmer’s Almanac.

So Thursday’s moon is also known as a “sturgeon supermoon.”

A full moon in March is known as a “worm moon.”