My toddler loves the science center. He doesn't really appreciate it yet for all the technical reasons it's cool, but he loves to play with the compressed air in the wind exhibit, flush the transparent toilet, and play with the balls on the "ball wall", a wall that uses vaccuum pressure, tubes, baskets and trap doors to make the balls travel and is reminiscent of the game "mouse trap". Oddly enough, he really doesn't appreciate the little "toddler corner", probably because it has all the same toys he has at home. For older kids there are appropriate exhibits as well that encourage tweens to create things and watch them work. Throw in the IMAX theater and cafe, and it's great for all-day fun and a little break for mom!
The Science Center is really cool. I like the fact that they offer classes for the homeschool students as well. Be sure to check their schedule and you do need to register in advance for it. There is a fee to attend the center and the classes. The planetarium is really cool, but who doesnt like to gaze at the stars?