On a brisk evening on 4th and South Streets, two telescopes are pointing at the night sky. Behind the viewfinders are brothers Bill Green and Brendan Happe — the Philly Moon Men. Bill and Brendan encourage anyone walking by in their Queen Village neighborhood to stop and look at the moon.

“All the shapes, forms, and craters and shadows,” Abraham Reyes said. “It’s really amazing.”

“So, we’ve really taken astronomy up as a hobby,” Green, the older brother, said. “We’ve both grown up on the East Coast. And it’s something special to be able to share the night sky with other people.”

Green is an engineer who uses lasers to test optical instruments like lenses for cameras.

He said cloudy or rainy weather conditions and Philadelphia’s light pollution make viewing the moon challenging, but he’s been able to show people some surprising things.

“We’ve been able to point at the phase of Venus. We’ve been able to see Saturn’s rings from South Street. We’ve even gotten a look at Juniper’s moons and the way they change position,” he said.

Happe, who makes up the other half of the Philly Moon Men, works as a manager at SugarHouse Casino. He’s frequently adjusting one of the telescopes with a remote control so the Earth’s rotation doesn’t push the moon out of their view.

“When you looked, did you notice the focal point is about a moon and a half wide,”Happe said. “So the moon moves one moon’s length every minute and a half. Through that, that’s almost halfway out of focus, so every 30 seconds or so, we have to we have to constantly track it.”

The Moon Men use several pieces of equipment. There’s a five-inch Newtonian telescope — that’s the one with the remote, there’s a four-inch Cassegrain reflecting telescope — which is good for viewing stars and galaxies, and they sometimes use a pair of high-tech binoculars. You can spend a lot of money on telescopes, but the brothers are very thrifty. They’ve snagged their equipment, stylish blazers and several astronomy books from Philly Aids Thrift — a thrift store in their neighborhood. Under one of the telescopes is a jar of cash donations. Happe said they give the money back to Philly Aids Thrift.

“We see the potential for the moon and its beauty, its craters, it’s mountains to unite people, to start conversations about astronomy, about what we have in common,” Happe said.

Local resident Nick Carmack recently moved to Philadelphia from Oregon. He said he’s always been interested in looking at stars, but learned something new about the moon.

“On my Tinder profile, it’s like, ‘Let’s go hiking and look at the stars,” Carmark said. “It’s fascinating to see some of these craters. I’d like to know if the craters have been mapped like the stars have been mapped? Now, I’m going to look this up.”

The Philly Moon Men will be out at night viewing the full moon until about December 27, and plan on viewing Jupiter in January.