Jennings Environmental Education Center, Route 528, Brady Township, hosts “Nature Detectives: The Case of the Curious Caterpillars” from 2 to 4 p.m. Sunday. Call 724-794-6011.

A star party sponsored by the Amateur Astronomers Association of Pittsburgh is scheduled to begin, weather permitting, at 7 p.m. Saturday at the Nicholas E. Wagman Observatory in Deer Lakes Regional Park near Russellton. Call 724-224-2510.