Astronomy questions This is a list of recently added questions about astronomy. Play astronomy quiz and see all the questions. Is the Moon's orbit around the Earth constant?It is slowly increasing. For several hundred million years, the Moon has gone so far that it will no longer be possible to complete the solar eclipse.Created by: Katarzyna Dąbrowskahard 50% It is constant.It is constant.1583It is slowly increasing.It is slowly increasing.3354It is slowly decreasing.It is slowly decreasing.1040It is impossible to measure.It is impossible to measure.687Moon riddles » What object collided with Earth according to giant impact hypothesis?A planet. According to the giant impact hypothesis Earth once collided with a planet of Mars size usually referred to as Theia, a titaness of Greek mythology, mother of Selene - Moon goddess, which is to reflect the believe the collision was an origin of the Moon. Created by: smyruhard 46% a cometa comet674a moona moon566an asteroid an asteroid 2260a planeta planet3020universe riddles » Which planet is this globe with such a bland look without any details?Uranus. Upper parts of Uranus' atmosphere are composed of condensed hydrocarbons, mainly methane crystal particles. Contrary to the rest of gas giant planets, it's hard to observe clouds and storm bounds.Created by: smyruaverage 61% UranusUranus8065NeptuneNeptune3497MercuryMercury606VenusVenus855planets riddles » 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 52% low temperatureslow temperatures1635lack of oxygenlack of oxygen4780poor gravitypoor gravity1286cosmic rayscosmic rays8614astronautics 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 30% GalaxyGalaxy934Galaxy filamentGalaxy filament1072Galaxy clusterGalaxy cluster104SuperclusterSupercluster1399space 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 29% CuriosityCuriosity1185OpportunityOpportunity709SojournerSojourner1092SpiritSpirit674space 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 49% It is a measure of the disorder in a closed system.It is a measure of the disorder in a closed system.3527It is a measure of system's sizeIt is a measure of system's size741Both answers are correctBoth answers are correct1396None of above answersNone of above answers1454physics 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: lanusienkavery easy 81% MercuryMercury7145VenusVenus692EarthEarth274MarsMars617Solar 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 55% The stelliferous eraThe stelliferous era899The degenerate eraThe degenerate era200The primordial eraThe primordial era148The black hole eraThe black hole era364 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 53% Great BearGreat Bear2196SiriusSirius2293CassiopeiaCassiopeia1469it is not visible at allit is not visible at all6974stars riddles » Play astronomy quiz and see all the questions.