Photo by Rob Cannon.

PRESIDENT: Get inside the mind of President Obama via The Atlantic’s national correspondent Jeffrey Goldberg, who will discuss “The Obama Doctrine.” sixth & i (600 I Street NW) 7 p.m. $15

PLUTO: Discover the dwarf planet Pluto with New Horizons’ Principal Investigator Alan Stern. National Academy of Sciences Building (2101 Constitution Avenue NW) 6:45 p.m. Free, but register here.

PING-PONG: Spend some time outdoors playing Berlin-style ping pong with Arlington neighbors. Winner gets a $25 gift card to Highline RxR. Pavilion at 2121 Crystal Park. 5:30-8:00 p.m. Free, but register here.

THEATER: See Round House’s production of Tennessee Williams’ Cat on a Hot Tin Roof first, and name your price. Round House Theatre (4545 East-West Highway, Bethesda, MD) 7:30 p.m., pay what you can.