you wake up one morning to find a UFO has landed in your backyard (an ULO?). The alien aboard says that he needs duct tape to fix his ship, and if you let him have a roll, he will let you borrow the UFO for 24 hours of ship time.

That's enough time for you to make one trip to pretty-much any place you'd like to go. You can go to a planet in our solar system. You can have a look at a giant star or a neutron star or a black hole. You can go any place you want - but you only have time to visit one place.

Where would you go?