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
ESO 3.6 m Telescope ESO 3.6 m Telescope The ESO 3.6 m Telescope is an optical reflecting telescope run by the European Southern Observatory at La Silla Observatory, Chile since 1977, with a clear aperture of about and area. The telescopes uses the HARPS instrument and has discovered more than 130 exoplanets. In 2012, it discovered Alpha Centauri Bb, a now-disproven possible planet in the Alpha Centauri system only 4.4 light-years away. It saw first light in 1976 and entered full operations in 1977. It received an overhaul in 1999 and a new secondary in 2004. When completed in the late 1970s, it was