How big is the universe?

So.... Apparently some objects are no longer available in the universe. I don't know which objects (or which universe for that matter) but it did mean I couldn't run the report I needed. Which got me thinking... How big is the universe? And has it run out of space already? Is it programmed to delete some objects when it is full? And how does it choose which ones to delete? Maybe it's a bit like my sky+ and gets rid of the oldest stuff first. Unless you put a big 'k' next to it. Next time I try to run my report I'll try sticking a big 'k' next to the objects I need...

In other news the open golf is already affecting the local traffic, and I've made no credible celebrity spots. But there's still time!