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
Exoplanet Exoplanet An exoplanet (, ) or extrasolar planet is a planet outside the Sun's solar system. The first evidence of an exoplanet was noted as early as 1917, but was not recognized as such. However, the first scientific detection of an exoplanet was in 1988, although it was not confirmed to be an exoplanet until later in 2012. The first confirmed detection occurred in 1992. There are many methods of detecting exoplanets. The High Accuracy Radial Velocity Planet Searcher (HARPS) has discovered about a hundred exoplanets since 2004, while the "Kepler" space telescope, since 2009, has found more than two