Ritchie Observatory presents the planetarium show “Mercury: the Fastest and Smallest Planet” at 7 p.m. Saturday, Feb. 8.

Mercury is a planet of many extremes. Join Astronomer Steve Ruhl on a journey to the first rock from the sun, a planet of fire and unlikely ice.

If the sky is clear, astronomers will be on hand with telescopes for public star-gazing.

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

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

For more information, call 206-842-9152 or visit www.bpastro.org.