The Mirror Blank

My friends Adam and Jess have been away at college, and are now back home for Christmas break and are going to resume working on the telescope mirror that they are grinding. Here Jess is examining it with a powerful magnifier, looking for "pits" in the surface. Grinding needs to continue until the pits are gone. They will get some more grinding done, but they will not get the mirror done until they are on summer break. You will be able to watch their progress right here.