Planets questions This is a list of recently added questions about planets. Play planets quiz and see all the questions. When Was the Dwarf Planet Pluto Discovered?In 1930. Pluto was discovered by Clyde Tombaugh in 1930 and was originally considered to be the ninth planet from the Sun. In 2006, with the introduction of the new definition of the planet, the platoon lost the status of the planet and was considered a dwarf planet.Created by: Tschuka hard 45% in 1800in 1800350in 1830in 18301764in 1900in 19001196in 1930in 19302809Solar System riddles » How many moons does Mars have? 2. Mars is the fourth planet from the sun. Mars has two Moons, Phobos and Deimos. They were both discovered in 1877, by Asaph Hall at the Naval Observatory in Washington DC. Created by: Tschuka hard 51% 1130022207033468Mars has no moonsMars has no moons1147Mars riddles » What is the hottest planet in the Solar System?Venus is by far the hottest planet in the Solar System, with a mean surface temperature of 462 °C, even though Mercury is closer to the Sun. What's interesting, studies have suggested that billions of years ago Venus's atmosphere was much more like Earth's than it is now, and that there may have been substantial quantities of liquid water on the surface.Created by: Ninjaihard 46% MercuryMercury359VenusVenus458MarsMars92JupiterJupiter66astronomy riddles » There are two know ice giants in the Solar System ...Neptune and Uranus. An ice giant is a giant planet composed mainly of elements heavier than hydrogen and helium, such as oxygen, carbon, nitrogen, and sulfur. There are two known ice giants in the Solar System, Uranus and Neptune.Created by: Tschuka hard 58% Jupiter and SaturnJupiter and Saturn34Uranus and PlutonsUranus and Plutons30Neptune and UranusNeptune and Uranus114Saturn and UranusSaturn and Uranus18curiosities riddles » In our solar system which two planets are known as gas giants?Jupiter and Saturn. A gas giant is a giant planet composed mainly of hydrogen and helium and as a result are sometimes known as a failed star since it contains the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. Created by: Tschuka very easy 81% Saturn and MarsSaturn and Mars1Saturn and PlutonSaturn and Pluton26Jupiter and SunJupiter and Sun12Jupiter and SaturnJupiter and Saturn170records riddles » 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 hard 44% A. Wolszczan and Dale FrailA. Wolszczan and Dale Frail4243G. CassiniG. Cassini1301E. HubbleE. Hubble2740no such planets were discoveredno such planets were discovered1174discoveries riddles » 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 very hard 25% Mercury and MarsMercury and Mars113Venus and EarthVenus and Earth327Jupiter and SaturnJupiter and Saturn72Uranus and NeptuneUranus and Neptune171space riddles » The largest impact crater of the Solar System is:Caloris Planitia is a plain within a large impact basin on Mercury, informally named Caloris, about 1,550 km in diameter. It is one of the largest impact basins in the Solar System. The crater, discovered in 1974, is surrounded by a ring of mountains approximately 2 km (1.2 mi) tall. Created by: Tschuka very hard 27% Valles MarinerisValles Marineris459CalorisCaloris381Rupos AltaiRupos Altai312AristarchusAristarchus250astronomy riddles » Where are the craters of Dostoyevsky, Chopin and Van Gogh?On Mercury. Discovered craters on Mercury are named after outstanding artists. In addition to the above, there are also craters on the Mercury map named after: A. Mickiewicz, L. van Beethoven, F. Goya and C. Monet.Created by: Tschuka very hard 29% On MercuryOn Mercury993On MarsOn Mars1275On UranusOn Uranus276There are no such cratersThere are no such craters820astronomy riddles » How long is stellar year on Mars?687 Earth days. The Martian year is almost twice longer than Earth's year.Created by: Tschuka very hard 28% 687 Earth days687 Earth days546423 Earth days423 Earth days282183 Earth days183 Earth days343121 Earth days121 Earth days728astronomy riddles » Play planets quiz and see all the questions.