A few astronomers continue to think there may yet be a Planet X out there8 – a real whopper, perhaps as much as ten times the size of Jupiter, but so far out as to be invisible to us. (It would receive so little sunlight that it would have almost none to reflect.) The idea is that it wouldn’t be a conventional planet like Jupiter or Saturn – it’s much too far away for that; we’re talking perhaps 4.5 trillion miles – but more like a sun that never quite made it. Most star systems in the cosmos are binary (double-starred), which makes our solitary sun a slight oddity.
Second sun in our solar system beyond Puto
