May 4, 2016 2 min read

The Amateurs Astronomers Association of Pittsburgh is planning to open its observatory in Mingo Creek County Park to the public when Mercury makes an unusual trip between the Earth and the sun Monday.

The group plans to start watching the event a little after 8 a.m. at Mingo Creek Observatory in Nottingham Township during the “transit” of Mercury, weather permitting.

“We’re hoping it’s going to be clear. And it looks like it’s going to be clear,” said Ken Kobus, a member of Amateur Astonomers who’s on the Mingo Observatory committee. “If it’s cloudy, we’re out of luck.”

There will be no charge to visit the observatory at that time.

Kobus, a retired steelworker who lives in Bethel Park, said the transit will begin at 7:13 a.m. but won’t be visible from the observatory until just past 8 a.m. because of the orientation of the building.

The planet’s transit between the Earth and the sun will continue until about 2:40 p.m.

“As it progresses, you’ll be able to see this little black spot moving across the sun,” Kobus said.

Kobus said the group is equipped with a filter for its telescope that allows a person using it to look at the sun safely.

He warned against trying to look at the sun using binoculars or a telescope without the filter.

“They’ll burn their eyes out. It’s like putting a magnifying glass up to your eye” and then training it at the sun, he said.

Kobus said Mercury, the first planet in the solar system, passes between the sun and Earth once every three to 10 years.

Venus, the second planet, does so only about once or twice every century, he said.