Pumpkin Chunkin’

A competition to see which team can launch a pumpkin from a catapult designed by students in science, technology, engineering and math classes and clubs. 2-4 p.m. Adults, $5; ages 3-17, $3; younger than 3, free. Robinson Nature Center, 6696 Cedar Lane, Columbia. Register, howardcountymd. gov/RNCpumpkinlaunch.htm, 410-313-0400.