Myst Island -- Planetarium. Found constellation plaques.

The plaque surronding the fountain have the constellations on them. They make a funny noise when you put your hand over them.

How do I work the constellation plaques?

I have the constellations selected, but nothing happens.

I've solved the constellations, but what happen?

Go back to Myst Island -- Planetarium. Constellations known.