What makes a racecar fast? How does animation work? What does a brain look like? These are just some of the plethora of questions that the 70 North Bay Discovery Day Science Fair exhibitors will invite kids to explore. Exhibits will feature a total of 97 hands-on activities involving optical illusions, microscopic organisms, radar, robots, animal tracking, rockets, and many other science-oriented topics. The fair will be held, rain or shine, on March 11, 10 a.m.–4 p.m., at the Sonoma County Fairgrounds in Santa Rosa. See a full list of exhibitors and activities at northbayscience.org.