Supermassive black holes are a one-way trip for mass falling in — or are they? At the upcoming planetarium show “Supermassive Black Holes,” astronomer Steve Ruhl will look at these beasts present in galaxies — how did they get there and how do they behave.

The show is 7:30 p.m. Saturday, Jan. 11 at the Edwin E. Ritchie Observatory at Battle Point Park.

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

BPAstro Kids are playing “Programming Games” this month. Join Dr. Erica Saint Clair from 4 to 5 p.m. Jan. 11 as BPAstro Kids embark on various programming games, both on boards and on computers.

Admission to the show is free to members of the Battle Point Astronomical Association; a $2 donation suggested for nonmembers, $5 for families.

BPAA 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 visit bpastro.org.