What Was The First Planet Discovered By Telescope?
Out of the nine planets in our solar system only three of them have been officially discovered. The rest of the planets in the solar system are observable, unaided, by the human eye. Although early man may not have had any idea that Mars was a planet and not a very bright red star it certainly wasn’t discovered by any specific person.
The introduction of the telescope in the 17th century changed all that. People began looking towards the sky with an enhanced eye, probing the secrets of the solar system. Early astronomers observed the same things their ancestors had observed; they simply did so with a radically more powerful gaze that revealed planetary rings and orbiting moons.
It wasn’t until the late 18th century, however, that an astronomer chanced upon a planetary body that had never been observed before. In 1781 Sir William Herschel–not only a famed astronomer but talented musician and prolific composer–was the first person to gaze upon the distance planet of Uranus and, in doing so, became the first person to officially discover a planet in our solar system. For the curious, the other discovered planets are Neptune (discoverd in 1846 by John Couch Adams) and Pluto (discovered in Clyde Tombaugh in 1930).
Herschel was a dedicated astronomer and invested a significant portion of his life to the science. Over the course of his life he built in excess of 400 telescopes including a 40-foot reflecing telescope with a 49.5″ diameter. His very first night using the 40 foot monster he discovered a previously unobserved moon in orbit around Saturn.
In addition to discovering Uranus, Herschel also discovered two moons of Saturn (Mimas and Enceladus) and two moons of Uranus (Titania and Oberon). Herschel also laid the foundation, through his observations and calculations, for our modern understanding of binary star systems. In addition to his work discovering planets and other inter-solar objects, Hershel also coined the term “asteroid”, discovered infrared radiation, and correctly calculated that the solar system is moving about upon the arm of the disk-like Milky Way in which our solar system resides. Due to the vast reach of his work and the contributions he made to the foundations of astronomy, Herschel is widely regarded as the greatest astronomer of the 18th century.