Sun Gun ready for its starring role at Philly solar eclipse party

Visibly excited by the coming of Monday's moon, which will briefly block 80 percent of the sun over Philadelphia, Mickey Maley spent Sunday preparing the Franklin Institute's huge Sun Gun telescope and dozens of other pieces of equipment so they will be ready to welcome crowds expected for solar eclipse festivities on the Benjamin Franklin Parkway.

"The last total solar eclipse around here was in 1478, long before 1492, when Columbus sailed the ocean blue," said Maley, the institute's assistant director of public programs.

The moon will black out all of the sun in some parts of the country, but even an 80 percent blackout here inspired Philadelphians to buy thousands of eclipse personal safety viewers, causing weekend sellouts. The Franklin Institute was sold out of 3,500 by Saturday, while the Philadelphia Zoo sold out of 1,200 on Saturday.

LATER TODAY: Derrick Pitts, the Franklin Institute's chief astronomer, will take your solar eclipse questions live on Philly.com's Facebook page at 3 p.m. Monday, just after the eclipse's peak in Philadelphia.

Besides the eye-popping Sun Gun, the free event in a pocket park next to the institute will include four smaller telescopes; 32 Sun Spotters, which project the eclipse onto paper; a number of handheld viewers; and four silver-black polymer tents within which people can safely watch the eclipse.

Although the event will run from 1:21 to 4:01 p.m., the near-total eclipse lasts only for two minutes and 40 seconds, beginning at 2:44 p.m.

Maley will post "Do Not Look Directly at the Sun" signs at the event. "People have asked if they can view the eclipse safely by holding a hand over their eyes," he said. "I tell them no, because your hand is not a filter."

As the Franklin Institute crew worked with the telescopes and viewers, a passerby asked Brittany Wickham, a staff science interpreter, if it was all right to swim laps in the pool during the eclipse.

"If you wear sunscreen and don't look at the sun, it's safe to swim," Wickham assured her.

Wickham said people had asked whether they should leave their pets inside during the eclipse: "I told them that if their dog doesn't look at the sun every other time it's out for a walk, you can trust it won't during a solar eclipse."

Maley said Monday's eclipse viewing will be accompanied by a science celebration. "We'll be blowing up stuff out of trash cans," he said.

Asked why, he laughed and said, "Because it's fun." It's also about the science of pressure, temperature, matter, thrust and lift, he added. "We'll be blowing up moon balls," he said, in honor of the moon blocking out the sun.

Maley said Philadelphia will have another near-total solar eclipse in 2024.  "My daughter is only 8 months old now," he said, "so she's a little young for this one."  But in 2024, that solar eclipse "will be something she'll always remember."