Question

first planet to be discovered​

Answer 1

Mercury, Venus, Mars, Jupiter and Saturn can all be seen with the naked eye, so it's impossible to say who was the first human to discover them, and when that was! Uranus was discovered by William Hershel on March 13, 1781.

Answer 2

Answer LONG BEFORE OUR SUN AND EARTH EVER EXISTED, A JUPITAR-SIZED PLANET FORMED AROUND A SUN-LIKE STAR .