Discovery and exploration of the Solar System Domenico Cassini later discovered four more moons of Saturn and the Cassini division in Saturn's rings. Edmond Halley realised in 1705 that repeated sightings of a comet were recording the same object, returning regularly once every 75–76 years. This was the first evidence that anything other than the planets orbited the Sun. Around this time (1704), the term "Solar System" first appeared in English. In 1781, William Herschel was looking for binary stars in the constellation of Taurus when he observed what he thought was a new comet. Its orbit revealed that it was a new planet, Uranus, the first
European Solar Telescope of Solar Physics in the world. As well as EAST intends to develop, construct and operate a next-generation large aperture European Solar Telescope (EST) in the Canaries, Spain. European Solar Telescope The European Solar Telescope (EST) is a pan-European project to build a next-generation 4-metre class solar telescope, to be located in the Canary Islands, Spain. It will use state-of-the-art instruments with high spatial and temporal resolution that can efficiently produce two-dimensional spectral information in order to study the Sun's magnetic coupling between its deep photosphere and upper chromosphere. This will require diagnostics of the thermal, dynamic and magnetic properties