Which planet of the Solar System was discovered using mathematics, not observation?

It truly amazes me that that long ago, scientists (mathematicians) were able to discover planets. Imagine what they can achieve now and into the future!

Dannybear79, I hate your comments toLily21. Ease up.people have the right to free speechm. and you shouldn't be name calling her anyway.

most astronomers are wrong. what about poor little pluto. downgraded to a moon. absolute rubbish

Charlie Epps is very proud of this discovery by Mathematics!

So far away, yet they figured it.

Me, the same- hence wise we are always evolving-why do people never answer to others questions-would make such a debate! ho hum