How does scanning work with other objects like asteroids?

Asteroids have a huge cross-section. Stars and things will have heat. You'll already be able to detect them, then it's a case of getting them lined up and scanning their information. You look at an asteroid, and you scan it. If you're in a fighter with a standard scanner, you'll see it's an asteroid. But if you get a mining scanner upgrade or exploration, you'll get more signals, because this is a mineral, this is a gas, etc… you can specialise your ship to scan asteroids or other things.