What happens when galaxies collide? Has our own galaxy experienced collisions and will it in the future? Astronomer Steve Ruhl will look at what to consider these questions with some of the latest data at the upcoming planetarium show “Galaxy Collisions and the Milky Way.”

The show is 7:30 p.m. Saturday, March 14 at the Edwin E. Ritchie Observatory at Battle Point Park. Admission is free to Battle Point Astronomical Association members; a $2 donation is suggested for nonmembers, $5 for families.

If the sky is clear, astronomers will be on hand with telescopes.

Before the show, from 4 to 5 p.m., BPAstro Kids will embark on a variety of citizen science projects.

The Battle Point Astronomical Association is a nonprofit amateur astronomy organization that operates the Ritchie Observatory and John H. Rudolph Planetarium in the Helix House at Battle Point Park.

For more information, call 206-842-9152 or go to bpastro.org.