The Rochester Museum & Science Center expands its already popular "Expedition Earth" exhibit with two new galleries. "You & Your Earth" and "An Ever-Changing Planet" join "Glaciers & Giants" starting Friday, January 18. The two new galleries will continue with "Glaciers & Giants" most successful elements, glorious dioramas (that mastodon really looks cool) and fun interactive activities (my nephew had to be physically pulled away from the "excavation pit").

"An Ever-Changing Planet" actually reaches further back than its predecessor, examining what Rochester was like 350 million years ago. And, surprise! It was at the bottom of a tropical sea south of the Equator. Bet you didn't see that one coming, did you? Find out how our humble little plot of land migrated north and above water line with this exhibit, which includes a simulated volcano and mini-earthquake to help teach kids about tectonics. An undersea diorama includes reproductions of all kinds of gilled wonders from the pre-dinosaur era.

"You & Your Earth" is a more contemporary look at our region, and how humans have impacted the local environment. Dioramas feature black bears, beavers, and Bergen Bog, and kids can put on their own shows at the child-sized Beaver Lodge's Willow Theater, which comes complete with puppets and costumes.

The Rochester Museum & Science Center is located at 657 East Avenue. Hours are Mondays-Saturdays, 9 a.m.-5 p.m.; Sundays noon-5 p.m. Admission is $9 for adults, $8 for seniors and students, $7 for kids 3-18, free for 3 and under. For more information visit rmsc.org or call 271-4320.