Astronomy questions This is a list of recently added questions about astronomy. Play astronomy quiz and see all the questions. 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.Created by: Władysław Pękalaspace riddles »hard 49% It is a measure of the disorder in a closed system.It is a measure of the disorder in a closed system.1128It is a measure of system's sizeIt is a measure of system's size258Both answers are correctBoth answers are correct467None of above answersNone of above answers441 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.Created by: lanusienkaplanets riddles »easy 77% MercuryMercury2221VenusVenus267EarthEarth126MarsMars243 Which era of the universe are we currently living in ?The stelliferous era. There are five eras of the universe which are the primordial era,the stelliferous era, the degenerate era, the black hole era and the dark eraCreated by: Palash Chakraborty<10 answersThe stelliferous eraThe stelliferous era4The degenerate eraThe degenerate era2The primordial eraThe primordial era1The black hole eraThe black hole era3 The closest star to Sun is Proxima Centauri. In which direction we would need to look to see it on the night sky?It is not visible at all. Proxima Centauri is a red dwarf and its average brightness is very low. That is why even though it is closest to Sun, it was discovered not until in 1915.Created by: Inesstars riddles »hard 49% Great BearGreat Bear992SiriusSirius1144CassiopeiaCassiopeia691it is not visible at allit is not visible at all2788 Which is the only moon with active volcanoes?Lo is a very tiny moon that is enormously influenced by the gravity of Jupiter. The great forces of Jupiter and its other moons exert such long pulls on lo that it deforms continuously from strong internal friction. These tides produce tremendous amount of internal friction, which heats the moon and enables its volcanic activityCreated by: ippili_chSolar System riddles »very hard 39% Titan Titan 389GanymedeGanymede533lolo846EuropaEuropa353 What is the name of the galaxies group to which Milky Way belong?Virgo Supercluster. The Virgo Supercluster or the Local Supercluster contains at least 100 galaxy groups including the Local Group, which in turn contains the Milky Way and Andromeda Galaxies. Yet, it is one of millions of superclusters in the observable universe.Created by: Krzysztof Moskalhard 46% Supercluster in LibraSupercluster in Libra406Virgo SuperclusterVirgo Supercluster1335Gemini SuperclusterGemini Supercluster670Ophiuchus AuperclusterOphiuchus Aupercluster482 Imagine that a distant civilization watches the Earth from 100 million light years away. What can they see right now?Dinosaurs. If a distant civilization watches the Earth right now, it sees its image from the past.Created by: Krzysztof Moskalphysics riddles »hard 54% skyscrapersskyscrapers229the future the future 739dinosaursdinosaurs3230early Earth with no life yetearly Earth with no life yet1727 When was the first rocket launched into space in the history of mankind?October 3, 1942. The first rocket that reached space was the German V2 rocket during a test flight Oct. 3, 1942.Created by: Krzysztof Moskalrockets riddles »hard 40% April 12, 1961April 12, 1961610October 3, 1942October 3, 19421121October 11, 1937October 11, 1937275October 4, 1957October 4, 1957729 Who was the first man to leave the spacecraft in space?Alexey Arkhipovich Leonov was a Soviet astronaut, general major pilot and two-time Hero of the Soviet Union. On 18 March 1965, he became the first human to conduct extra-vehicular activity, exiting the capsule during the Voskhod 2 mission for a 12-minute spacewalk.Created by: Paweł KołodziejczykSoviet Union riddles »hard 42% Neil Alden ArmstrongNeil Alden Armstrong839Edwin Eugene Buzz Aldrin, Jr.Edwin Eugene Buzz Aldrin, Jr.329Alexey Arkhipovich LeonovAlexey Arkhipovich Leonov1756Yuri Alekseyevich GagarinYuri Alekseyevich Gagarin1182 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.Created by: Paweł Kołodziejczyktourism riddles »very hard 39% Neil Alden ArmstrongNeil Alden Armstrong1018Guy LalibertéGuy Laliberté410Dennis TitoDennis Tito1312Richard GarriottRichard Garriott619 Play astronomy quiz and see all the questions.