Trahan School 4th grade star party

Last night the North Shore Amateur Astronomy Club provided a class and star party for the 4th grade classes at Trahan School in Tewksbury, Mass. I was asked to present the indoor class. There were about 30 students and 15 parents ready to go at 7pm. Jim Foy brought the group's LCD projector and the custodian provided a nice screen. The PAC contact, Kathy C., also brought hot chocolate and donuts. The kids got theirs at 7:30 just before going outside, and Kathy was nice enough to bring hot chocolate out to the cold astronomers. Mmmmm!

I enjoy these opportunities a lot, and I try to cover as many things in my presentation as possible. However, I am aware that it is already dark outside, so every minute I talk is a minute the kids are not looking through an eyepiece. Quite a challenge to try to prepare them adequately without wasting any time.

One thing I try to cover is the cosmic distance scale. Sometimes I make up new units to keep things simple. For instance, the Milky Way is 100,000 light years across give or take. Our closest neighbor galaxy is Andromeda which is 2.5 million L.Y. distant. To make this a little easier to compare, I show the kids that Andromeda is 25 "Milky Way diameters" away, with pretty much nothing but empty space in between. 25 is a number they can comprehend.

I also use a 12" beach ball and a 3" nerf ball (for earth and moon) and invite kids up to hold the "moon" at the distance they think it orbits from "earth". Most stand 3-5 feet away. The moon actually orbits 30 earth diameters away, so after getting a good crowd of 'guessers' I give a pre-measured piece of string rolled on a stick to another child and ask them to unroll it until they get to the end. They end up 30 feet out, which seems really far. (I remind them that at this scale the ISS orbits about an inch above the beach ball.) And I always comment on how brave the Apollo astronauts were for going so far from home. Things quiet right down as people contemplate that.

I showed them slides of open clusters, globular clusters, double stars, distant galaxies, and encouraged them to ask the astronomer at the scope whether what they were looking at was inside or outside the Milky Way.

Then the kids went outside, and there were about five or six scopes set up, courtesy of the members of NSAAC. I came out later and set up the 80mm refractor, and most kids who came over had already seen M13, the double cluster, the Plieades, Jupiter, and Andromeda so they got a good cross section.

The Milky Way was *just* barely visible at zenith, but the back yard we used was better (darker) than the baseball diamond that was used last year. Seeing was actually quite good, very little star twinkling and Jupiter was rock solid even at 8:30pm when it was quite low.