A program on “Interstellar Volcanoes” will be held from 6 to 8 p.m. Sunday in the Discovery Center at Oakwoods Nature Preserve.

The program will be in the inflatable planetarium and participants must sit on the floor.

The free family program requires registration, due to limited space. Registration must be made by noon Sunday at www.HancockParks.com under “Programs & Activities.” There is a 25-person maximum.