Have your kids ever looked up at the stars and asked you to explain why the lights are twinkling? Have they ever looked down at their own bodies and asked you to explain why they are tinkling? Chances are they've posed questions like these, and chances are, unless you have a background in science, you've been stymied. Fortunately, two intriguing exhibits geared to children explore matters both cosmological and biological.

The Boston Children's Museum is presenting My Sky through January 4, 2015. Developed in conjunction with NASA and the Smithsonian Astrophysical Observatory, it encourages kids (and their parents) to consider the universe and our place in it. As with nearly everything at the museum, much of the exhibit is interactive and hands-on.

My Sky invites visitors to observe the Sun in a dome that allows them to trace its path and learn about concepts such as rotating planets. By casting their own shadows, children can create human sundials. The Moon also takes center stage as kids play with a model that encourages them to discover its phases. In another domed theater, the nighttime sky puts on a time-lapse show that condenses an evening into a few minutes.

Kids have an innate fascination with boogers, burps, and other bodily byproducts. The Museum of Science capitalizes on the allure of the rude and crude with GROSSOLOGY: The (Impolite) Science of the Human Body. The exhibit, which will run through September 1, 2014, has displays such as Nigel Nose-It-All and Urine: The Game. The topics and presentations may not be genteel, but the science behind all of the grossness should get kids thinking. Should your kids want to nose around the stars as well as nasal cavities at the MOS, you could take them to shows in the museum's Charles Hayden Planetarium.

Photo: Boston Children's Museum.