Astronomy questions This is a list of recently added questions about astronomy. Play astronomy quiz and see all the questions. Mars colonisation is a hype topic. What is the biggest threat for those wishing to take a part in a journey to Mars?Cosmic rays. The only efficient protection against high energetic cosmic radiation, one we are granted with, is Earth magnetic field. Both during a long flight to Mars and through the stay on the planet, that did not form electromagnetic field, astronauts would be exposed to ionization. Created by: smyruhard 47% low temperatureslow temperatures1207lack of oxygenlack of oxygen3386poor gravitypoor gravity976cosmic rayscosmic rays5046planets riddles » 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. Created by: smyruvery hard 28% GalaxyGalaxy457Galaxy filamentGalaxy filament384Galaxy clusterGalaxy cluster50SuperclusterSupercluster468space 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.Created by: smyruvery hard 28% CuriosityCuriosity358OpportunityOpportunity220SojournerSojourner337SpiritSpirit250space 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.Created by: Władysław Pękalahard 50% It is a measure of the disorder in a closed system.It is a measure of the disorder in a closed system.1556It is a measure of system's sizeIt is a measure of system's size343Both answers are correctBoth answers are correct590None of above answersNone of above answers562physics 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.Created by: lanusienkaeasy 77% MercuryMercury2872VenusVenus346EarthEarth161MarsMars309Solar System riddles » 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 Chakrabortyhard 52% The stelliferous eraThe stelliferous era10The degenerate eraThe degenerate era4The primordial eraThe primordial era4The black hole eraThe black hole era1 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: Ineshard 52% Great BearGreat Bear1119SiriusSirius1268CassiopeiaCassiopeia786it is not visible at allit is not visible at all3562stars riddles » 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_chhard 40% Titan Titan 484GanymedeGanymede680lolo1099EuropaEuropa440Solar System riddles » 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 Libra457Virgo SuperclusterVirgo Supercluster1535Gemini SuperclusterGemini Supercluster735Ophiuchus AuperclusterOphiuchus Aupercluster549 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 Moskalhard 55% skyscrapersskyscrapers256the future the future 834dinosaursdinosaurs3732early Earth with no life yetearly Earth with no life yet1932physics riddles » Play astronomy quiz and see all the questions.