The most difficult space riddles A list of space related questions that are most often answered incorrectly Astronomy quiz Which of the following cosmic structures is the largest?Galaxy filaments are the largest known structures in the universe. They group galaxy superclusters, which in turn are formed by cluster composed of galaxies. Hercules–Corona Borealis Great Wall is considered the largest known structure of Universe. It is estimated to span 10 billions light years. very hard 28% GalaxyGalaxy33%Galaxy filamentGalaxy filament28%Galaxy clusterGalaxy cluster3%SuperclusterSupercluster34%Created by: smyru. Statistics based on 1385 answers in 2 languages »astronomy riddles » Which rover was the first to explore Mars?Sojourner was the first Mars rover. It was much smaller then Curiosity, whose wheel is about the size of the whole Sojourner. It landed on July 4, 1997 as part of Mars Pathfinder mission on Mars's Ares Vallis and remainded in contact with Earth till September 27, 1997.very hard 29% CuriosityCuriosity30%OpportunityOpportunity18%SojournerSojourner29%SpiritSpirit21%Created by: smyru. Statistics based on 1191 answers in 2 languages »astronomy riddles » What is the name of first in history cosmic tourist (astrotourist)?Dennis Tito. Dennis Anthony Tito is an American engineer and multimillionaire, most widely known as the first space tourist to fund his own trip into space. Tito paid a reported $20 million to the Russian Federal Space Agency.hard 40% Neil Alden ArmstrongNeil Alden Armstrong29%Guy LalibertéGuy Laliberté12%Dennis TitoDennis Tito40%Richard GarriottRichard Garriott17%Created by: Paweł Kołodziejczyk. Statistics based on 4063 answers in 2 languages »tourism riddles » What are the most luminous objects in the universe?Quasars. A quasar is an extremely energetic source of radiation powered by accretion disc around galaxy's central supermassive black hole. Quasars were much more common in the early universe, as all known quasars are extremely distant.hard 41% supergiant starssupergiant stars8%novaenovae3%supernovaesupernovae45%quasarsquasars41%Created by: globalquiz.org. Statistics based on 7054 answers in 2 languages »light riddles » What is entropy?It is a measure of the disorder in a closed system. It is a measure of the disorder or randomness in a closed system. The second law of thermodynamics states that if isolated thermodynamic system spontaneously evolves into another state of equilibrium, its entropy will always increase. The term was invented by Rudolf Clausius.hard 51% It is a measure of the disorder in a closed system.It is a measure of the disorder in a closed system.51%It is a measure of system's sizeIt is a measure of system's size11%Both answers are correctBoth answers are correct19%None of above answersNone of above answers18%Created by: Władysław Pękala. Statistics based on 3098 answers in 2 languages »physics riddles » How many times is Jupiter's volume larger than Earth's volume?1,321 times. Jupiter is so big, that it is almost the size of a star. The smallest known red dwarf is just 16 percent larger in diameter than Jupiter.hard 56% 800 times800 times17%1,321 times1,321 times56%50 times50 times8%10,000 times10,000 times16%Created by: K.R.A.C.. Statistics based on 5474 answers in 2 languages »planets riddles » How long did it take Apollo 11 flight to reach the Moon? 3 days. It took 1 minute of flight to reach Mach 1 and 12 minutes to enter Earth's orbit. After one and a half orbits, the third-stage engine pushed the spacecraft onto its three-day long travel to the Moon.average 61% 30 minutes30 minutes4%3 hours3 hours15%3 days3 days61%30 days30 days18%Created by: Hitter smasher. Statistics based on 7735 answers in 2 languages »rockets riddles » Which planet of the solar system has the smallest surface?Mercury has a surface of 75x10^6 km^2, which is equal to 14,7% of Earth' surface.easy 77% MercuryMercury77%VenusVenus9%EarthEarth4%MarsMars8%Created by: lanusienka. Statistics based on 3736 answers in 2 languages »Solar System riddles » Play astronomy quiz and see all the questions.