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
Kepler-10b revealed to be a lava-ocean planet, whereas Kepler-10b must be predominantly made of rock or iron. In addition to showing the range of masses and radii consistent with the observations of each planet, the plot includes curves of compositions implied by certain masses and radii. Kepler-10b is tidally locked to its parent star and has extreme variations in temperature between day and night sides. It also reflects about half of the starlight it receives. Kepler-10b Kepler-10b is the first confirmed terrestrial planet to have been discovered outside the Solar System by the Kepler Space Telescope. Discovered after several months of