Space - Kepler Orrery IV

It's because of the methods that are being used to show that there are planets only work for certain cases, namely planets that are close to their sun. I don't think anyone has actually seen any of these planets, we've just seen wobbling or microlensing to detect the effect of the planet on their sun or the light coming from it. There's almost certainly planets at distances similar to Earth, but no one can prove it yet. It's a pretty young science!