We got tickets.
For those that missed it in previous years, the Lick Observatory ticket sales are open. Tickets sell out fast, make sure to book a babysitter. Having attended 2 walking tours and Concert of the Spheres, I most recommend the walking tour though it's long and a lot of walking, it's really amazing.
https://ucsctickets.universitytickets.com/user_pages/category.asp?id=32