Photo by wolfkann

DOGS IN COSTUME: The Park Hyatt Washington (1201 24th Street NW) presents “Paws at the Park,” a dog costume contest and happy hour to benefit the Washington Animal Rescue League. $14 admission includes 2 beer or wine tickets, Halloween candy, and dog treats. 6:00-8:00 p.m.

MUSIC: As noted in the Weekly Music Agenda on Monday, there are lots of live music options going on tonight. Catch Titus Andronicus at the Rock And Roll Hotel (7:00 p.m., $20), Aimee Mann and Ted Leo at the Birchmere (7:30 p.m., $49.50), Miike Snow at the 9:30 Club (10:30 p.m., $35), and The Sea and Cake at Black Cat (8:00 p.m., $15).

SPACE: Bill Nye the Science Guy moderates a discussion on the past 50 years of Solar System Exploration at National Geographic Live (1600 M Street NW) tonight. The panel at the event will be made of of NASA scientists, including “Kevin Hand, a Nat Geo Emerging Explorer who is searching for water on Jupiter’s moon Europa, Bethany Ehlmann, who analyses Mars’ mineralogy using remote sensing, Margaret Kivelson, who has researched the magnetic signatures of Jupiter’s moons, and Ed Stone, former director of NASA’s Jet Propulsion Laboratory.” This is the first in a three-part Explore More Series. 7:30 p.m. $20 for tonight, or $57 for all three events.

TRIVIA: Test your knowledge of “frontier legends, soldiers, politicians, and Wild West folk heroes” at the National Portrait Gallery’s (Kogod Courtyard, 8th and F Streets NW) The Wild, Wild West pop quiz trivia game tonight. 5:00-8:00 p.m. Free.