Sat. Jan. 2 & Sun. Jan. 3 

Last call ! When someone asks you "Whatever Happened to Pluto?" do you first think "Something has happened to the Disney dog?" or do you go, "Yes, I believe it's somehow not a planet anymore. How could that be?" To be honest, both thoughts flooded our head when we heard about the Museum of Science exhibit, but - clever as we are - we deduced this had to be about the planet, not the cartoon dog. We were right, and went to the opening of the exhibit in the Charles Hayden Planetarium in April. Haven't been inside a planetarium since ... um ... childhood. And it was fascinating, both the experience of simply leaning back and looking at the projected sky and the presentation about Pluto.

 Sat. Jan. 2 & Sun. Jan. 3 

Last call! When someone asks you "Whatever Happened to Pluto?" do you first think "Something has happened to the Disney dog?" or do you go, "Yes, I believe it's somehow not a planet anymore. How could that be?" To be honest, both thoughts flooded our head when we heard about the Museum of Science exhibit, but - clever as we are - we deduced this had to be about the planet, not the cartoon dog. We were right, and went to the opening of the exhibit in the Charles Hayden Planetarium in April. Haven't been inside a planetarium since ... um ... childhood. And it was fascinating, both the experience of simply leaning back and looking at the projected sky and the presentation about Pluto.

 We learned a few things. The idea of a planet is sort of mutable. There's a lot of debate, and no answers, really about what constitutes a planet and in this 45-minute presentation, we find out how close examination of the planet - its odd orbit in particular - led scientists to believe it was not part of our solar system but something called the Kuiper Belt, named after the scientist who discovered the band of rocky, frigid chunks of matter, a source of comets. And, thus the belief that if Pluto were placed near the sun it would develop a fiery tail and behave very much like a comet. Now, the Pluto controversy didn't upset my world, but it did disturb a certain feeling about order. You know we learned about our solar system years ago, and, darnit, now it's changed, without really changing? Well, science is an open-ended sort of game. As Robin Symonds, manager of Hayden, says, "This is what science is all about. We have to go where the evidence points. We have to constantly revise what we know and keep an open mind." So, Pluto is now called a "dwarf" planet by the International Astronomical Union." Oh, and did you know once upon a time it was throught there were even more planets in our system? Also, you'll be quite amazed at what the Zeiss Star Projector - a rotating star stimulator that sits in the middle of the 240-seat planetarium - can do. Check the website below for showtimes. Tickets: $9.

Science Park, 617-723-2500 www.mos.org