On Wednesday, the Lawrence Hall of Science is hosting "What Wonderful Worlds: Exploring our Solar System with Imke de Pater" who is professor and chair of UC Berkeley's Dept of Astronomy.
There's a discussion from 11 to noon, followed by space activities from noon to 2 p.m. It's part of the summer fun days program.
When: Wednesday, July 18 from 11-2
Who: everyone (including kids)
Where: Lawrence Hall of Science, Berkeley
Cost: Event is free (though I suspect you'll have to pay to get into the museum)