With 15-foot lightning bolts in the Theater of Electricity and a 20-foot-long Tyrannosaurus rex model, this is just the place to ignite any child's scientific curiosity. Occupying a compound of buildings north of Massachusetts General, the museum sits astride the Charles River Dam. More than 550 exhibits cover astronomy, astrophysics, anthropology, progress in medicine, computers, the organic and inorganic earth sciences, and much more. The emphasis is on hands-on education. For instance, at the "Investigate!" exhibit children explore such scientific principles as gravity by balancing objects -- there are no wrong answers here, only discoveries. Children can learn the physics behind everyday play activities such as swinging and bumping up and down on a teeter-totter in the "Science in the Park" exhibit. Other displays include "Light House," where you can experiment with color and light, and the perennial favorite, "Dinosaurs: Modeling the Mesozoic," which lets kids become paleontologists and examine dinosaur bones, fossils, and tracks.

The Charles Hayden Planetarium (617/723-2500), with its sophisticated multimedia system based on a Zeiss planetarium projector, produces exciting programs on astronomical discoveries. Laser light shows, with laser graphics and computer animation, are scheduled Thursday through Sunday evenings. The shows are best for children older than five. Admission to the planetarium is $4 if you paid the admission for the museum and $9 for the planetarium alone. The Museum of Science includes the Mugar Omni Theater (617/723-2500), a five-story dome screen. The theater's state-of-the-art sound system provides extra-sharp acoustics, and the huge projection allows the audience to practically experience the action on-screen. Try to get tickets in advance online or over the phone. Admission for shows is $9 (or $4 if you paid the admission for the museum). Call or check the museum's Web site for showtimes. Although the museum is usually viewed as a family destination, a more-adult crowd appears on Friday nights from 6 to 10 for the Science Street Café, where you can sip a martini and enjoy better-than-usual museum food to the sounds of live music. Afterwards, stroll through near-empty exhibit halls for a late viewing or climb up to the Gilliland Observatory for a romantic up-close glimpse of the nighttime sky.