The Philadelphia Science Festival closes with its traditional carnival, moved from the Parkway to the Great Plaza at Penn's Landing. It will feature more than 150 exhibitions, hands-on experiments, and performances, including live animals from the Philadelphia Zoo, wrestling robots, and more. (There will be exploding stuff, we think.)

10 a.m. to 4 p.m. Saturday at Great Plaza at Penn's Landing, 101 S. Columbus Blvd. Admission is free. Information: philasciencefestival.org

Catch a falling 'Star'

Kids ask questions, many with no answers (many). For example, "How did Peter become Pan?"

Now, you have an answer to that one. Dave Barry and Ridley Pearson imagined what came before J.M. Barrie's enduring tale in their 2006 book Peter and the Starcatcher, in which the orphaned and shanghaied Peter meets the starcatcher Molly. Starcatchers are charged with collecting starstuff. Starstuff? It's complicated (ask your kids to explain it). It's a story full of pirates, magic, mermaids, and flying cats. In short: fun.

Rick Elice's stage adaptation of the book finishes its run this weekend at the Walnut Street Theatre.

8 p.m. Friday, 2 and 8 p.m. Saturday, at Walnut Street Theatre, 825 Walnut St. Tickets: $20 to $85. Information: 215-574-3550 or walnutstreettheatre.org

Looking sharp

Baby porcupines. Need we say more?

The Elmwood Park Zoo's porcupines Ivanna and Lola have both given birth. The two new arrivals, both male, are cute, and, surprisingly, cuddly. (A baby porcupine's quills are soft, but will begin to harden and grow as it matures.)

Stop by to see them while they're still at this stage. They grow up so fast.

At Elmwood Park Zoo, 1661 Harding Blvd., Norristown. Tickets: $16.95; $14.95 students; $12.95 seniors and ages 3 to 12; ages 2 and younger free. Information: 610-277-3825 or elmwoodparkzoo.org