10 most difficult planets riddles A list of ten (out of 22) planets related questions that are the most often answered incorrectly Planets quiz 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%.very hard 19% Mercury and MarsMercury and Mars17%Venus and EarthVenus and Earth51%Jupiter and SaturnJupiter and Saturn11%Uranus and NeptuneUranus and Neptune19%Created by: Tschuka . Statistics based on 442 answers in 2 languages »space riddles » 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.very hard 22% DioneDione12%RheaRhea30%EnceladusEnceladus34%IapetusIapetus22%Created by: Ninjai. Statistics based on 2101 answers in 2 languages »Solar System 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. very hard 23% Valles MarinerisValles Marineris34%CalorisCaloris23%Rupos AltaiRupos Altai23%AristarchusAristarchus18%Created by: Tschuka . Statistics based on 1184 answers in 2 languages »astronomy riddles » How long is stellar year on Mars?687 Earth days. The Martian year is almost twice longer than Earth's year.very hard 28% 687 Earth days687 Earth days28%423 Earth days423 Earth days12%183 Earth days183 Earth days17%121 Earth days121 Earth days40%Created by: Tschuka . Statistics based on 1780 answers in 2 languages »Mars 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.very hard 28% On MercuryOn Mercury28%On MarsOn Mars38%On UranusOn Uranus8%There are no such cratersThere are no such craters25%Created by: Tschuka . Statistics based on 3188 answers in 2 languages »astronomy riddles » 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. very hard 29% NeptuneNeptune16%UranusUranus29%Jupiter and SaturnJupiter and Saturn32%PlutoPluto20%Created by: Tschuka . Statistics based on 3063 answers in 2 languages »technology riddles » 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).very hard 32% JupiterJupiter3%SaturnSaturn3%UranusUranus32%NeptuneNeptune59%Created by: Tschuka . Statistics based on 4568 answers in 2 languages »astronomy riddles » What is the largest object in Kuiper's belt?Pluto. The chilly expanse of Kuiper Belt holds trillions of objects, remnants of the early Solar System. Pluto, no longer considered a planet, can now be claimed a king of the Kuiper belt, the region of thousands of icy worlds that orbit the sun beyond Neptune. very hard 34% ErisEris20%PlutoPluto34%CeresCeres35%HaumeaHaumea9%Created by: Tschuka . Statistics based on 889 answers in 2 languages »astronomy riddles » The axis of rotation of this planet is tilted sideways, nearly into the plane of its solar orbit. Uranus. Sometimes the Earth is close to the extension of its axis of rotation. Then it is possible to observe Uranus' moons revolve around the planet.very hard 34% UranusUranus34%MarsMars20%MercuryMercury18%JupiterJupiter25%Created by: Tschuka . Statistics based on 7623 answers in 2 languages »technology riddles » 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.hard 42% volcanic peaksvolcanic peaks3%atmospheric stormsatmospheric storms23%Jupiter moonsJupiter moons42%multiple magnetic poles of Jupitermultiple magnetic poles of Jupiter29%Created by: globalquiz.org. Statistics based on 17683 answers in 2 languages »physics riddles » Play planets quiz and see all the questions.