Sadly, when you fly to some distant planet in Sandbox mode (eeloo) and decide to collect some science. Materials, temperature. Why should we not know these things? Okay, so you open up the science JR.. uh oh. It either tells you nothing or say to you that the Research and Development is closed so you can't understand anything. Its the same on Kerbin, want to see the temperature? Nope, can't do that. Barometer? Nope.
Some may say its because your in Sandbox and it shouldn't matter because you've unlocked everything, but it does matter. Its all about the roleplaying.
I want to fly to Duna, and be able to tell its temperature during noon, dusk and dawn. However, I can't do this. The display seems to be telling nonsense at the same time. Its frustrating that basic instruments aren't able to be used in Sandbox.
Science should be able to be collected in Sandbox.