SUMMER NIGHT SKY -- Today at 1 p.m. Ages 4-12. The only planetarium in the National Park system offers a show devoted to the stars, planets and constellations seen in August. Rock Creek Park Nature Center, 5200 Glover Rd. NW. Free. 202-895-6070.
CHILDREN'S DAY AT GADSBY'S TAVERN -- Tuesday-Thursday, 10 a.m.-3 p.m. Tuesday: ages 3-6. Wednesday: grades K-3. Thursday: grades 4 and higher. Hands-on activities, storytelling and games about 18th-century tavern life. Gadsby's Tavern Museum, 134 N. Royal St., Alexandria. $3. 703-838-4242.
TRAVEL TOY -- Wednesday at 11:30 a.m. and 1:30 p.m. Make a portable game to take on vacation. National Building Museum, 401 F St. NW. $3. 202-272-2448.
WINSLOW HOMER -- Friday and Saturday, 10 a.m.-2 p.m. Ages 5 and older. Explore nature in paintings and watercolors by American artist Winslow Homer, and create your own work of art with oil pastels. National Gallery of Art, East Building, Fourth Street and Constitution Avenue NW. Free. 202-737-4215.
BRUNDIBAR -- Saturday and Aug. 14 at noon and 2 p.m. Players from Washington National Opera's Opera Camp for Kids present Hans Krasa's 1943 children's opera, originally performed by Jewish children in the Terezin concentration camp. Round House Theatre, East-West Highway and Waverly Street, Bethesda. Free. For reservations, call 202-448-3465.
EXPLORATORY POST: OWNEY -- Saturday, 1-4 p.m. Irene Kelly, author of "A Small Dog's Big Life" and Dirk Wales, author of "A Lucky Dog," read stories about Railway Mail Service mascot Owney the dog. Participants create an Owney tag and hunt for hounds around the museum. Book signings follow. National Postal Museum, 2 Massachusetts Ave. NE. Free. 202-633-5535.