Top 10 planets facts Selected as the most interesting among planets related questions in Planets quiz This is the aurora of Jupiter. What are the visible bright spots caused by?Jupiter moons. Jupiter's moons, especially Io (spot on the left), are powerful sources of auroras on Jupiter. These arise from electric currents along field lines, generated by a dynamo mechanism due to the relative motion between the rotating planet and the moving moon.Created by: globalquiz.orgSolar System facts » Which planet is the brightest seen from Earth?Venus is much brighter than other planets. It is due to its proximity to the Sun (source of light), and bright clouds of sulfuric acid in its atmosphere.Created by: globalquiz.orgastronomy facts » Which of Saturn's natural satellites has such distinctive equatorial ridge?Iapetus. The ridge is 13 km high, 20 km wide and 1300 km long. Its origin is not known, but considering the amounts of craters it's safe to assume that this is a very old geological creation.Created by: Ninjaiastronomy facts » Which planet of the Solar System is the coldest?Uranus is the seventh planet from the Sun. It has the coldest planetary atmosphere in the Solar System, with a minimum temperature of 49 K (−224 °C; −371 °F).Created by: Tschuka space facts » Most of the planets of the solar system were known in antiquity. Which was the first discovered in modern times with a telescope?Uranus. Like the classical planets, Uranus is visible to the naked eye, but it was never recognised as a planet by ancient observers because of its dimness and slow orbit. Sir William Herschel announced its discovery on 13 March 1781, expanding the known boundaries of the Solar System for the first time in history and making Uranus the first planet discovered with a telescope. Created by: Tschuka technology facts » How long is stellar year on Mars?687 Earth days. The Martian year is almost twice longer than Earth's year.Created by: Tschuka Mars facts » Which two planets are the closest in size?Uranus and Neptune. The diameters of Uranus and Neptune are respectively 25 362 km and 24 622 km - the difference is only 2.92%.Created by: Tschuka space facts » Who discovered the first planet outside the Solar System?A. Wolszczan and Dale Frail. Aleksander Wolszczan (born 29 April 1946 in Szczecinek, Poland) is a Polish astronomer. He is the co-discoverer of the first extrasolar planets and pulsar planets.Created by: Tschuka discoveries facts » Which planet is the closest in size to Earth?Venus. The equatorial diameter of Venus is about 95% the size of the Earth's equatorial diameter. Moreover, its mass, density and orbit is also closest to those of Earth.Created by: Kasiatechnology facts » Which planets in the Solar System have no natural satellites?Mercury and Venus. Only Mercury and Venus have no natural satellites.Created by: globalquiz.orgastronomy facts » Play planets quiz and see all the questions.