[Gayle]

What I want to know is how the scientists know how big these plants/stars are from so far away. Ok, they've made a telescope but the only way to actually test the accuracy of said telescope is to visit one of these distant places to use as a reference point. And yes, they've made smaller telescopes and checked the scope of them and multiplied it up to calculate how impressive the big telescope is but how do the really know.

For all we know it might be painted on a curtain!