10 most difficult astronomy riddles A list of ten (out of 155) astronomy related questions that are the most often answered incorrectly Astronomy quiz The speed to let the rocket enter the orbit is ...VI = 7,91 km/s. And cosmic velocity - also referred to as the circular velocity, it is the speed that should be given to the body to enter into orbit around Earth. If a rocket launches from the surface of the earth, then it has to get at least 7.9 kilometers per second to get into orbit.very hard 15% vI = 7,91 km/svI = 7,91 km/s15%vII = 11,19 km/svII = 11,19 km/s35%vIII = 16,7 km/svIII = 16,7 km/s15%Depends on the weight of the rocketDepends on the weight of the rocket34%Created by: Tschuka. Statistics based on 4223 answers in 3 languages »weapons riddles » What is the second brightest star in the night time sky, after Sirius?Canopus is the brightest star in the southern constellation of Carina, and the second brightest star in the night time sky, after Sirius. Its name is generally considered to originate from the mythological Canopus, who was a navigator for Menelaus, king of Sparta.very hard 19% ArcturusArcturus15%CanopusCanopus19%VegaVega54%ProcyonProcyon11%Created by: Ninjai. Statistics based on 162 answers in 3 languages »stars riddles » In which layer of the atmosphere the aurora is created?In the Thermosphere. Auroras are produced when the magnetosphere is sufficiently disturbed by the solar wind that the trajectories of charged particles in both solar wind and magnetospheric plasma, mainly in the form of electrons and protons, precipitate them into the upper atmosphere (thermosphere/exosphere) due to Earth's magnetic field, where their energy is lost. very hard 20% In the TroposphereIn the Troposphere22%In the StratosphereIn the Stratosphere37%In the mesosphereIn the mesosphere20%In the ThermosphereIn the Thermosphere20%Created by: Tschuka. Statistics based on 835 answers in 3 languages »atmosphere riddles » What is the diameter of the Milky Way?100 000 thousand light years. The diameter of our galaxy - the Milky Way is 100,000 light years. The Sun is located about 26,000 light years from its center.very hard 20% 100 000 thousand light years100 000 thousand light years20%200 000 thousand light years200 000 thousand light years26%500 000 thousand light years500 000 thousand light years31%1 000 000 thousand light years1 000 000 thousand light years22%Created by: Tschuka. Statistics based on 581 answers in 3 languages »numbers riddles » What is the largest discovered star? (by radius)UY Scuti is a bright red supergiant and pulsating variable star in the constellation Scutum. It is currently the largest known star by radius and is also one of the most luminous of its kind. It has an estimated radius of 1,708 solar radii (1.188×109 kilometres; 7.94 astronomical units); thus a volume nearly 5 billion times that of the Sun. It is approximately 2.9 kiloparsecs (9,500 light-years) from Earth. If placed at the center of the Solar System, its photosphere would at least engulf the orbit of Jupiter.very hard 24% VY Canis MajorisVY Canis Majoris32%V396 CentauriV396 Centauri31%UY ScutiUY Scuti24%Alfa PerseiAlfa Persei11%Created by: Dev. Statistics based on 1628 answers in 3 languages »space riddles » What is the name of the hypothetical last stage of the evolution of Sun-sized stars?Black dwarf. A black dwarf is a theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently that it no longer emits significant heat or lightvery hard 24% White dwarfWhite dwarf22%Black dwarfBlack dwarf24%Gray dwarfGray dwarf3%Red dwarfRed dwarf49%Created by: Tschuka. Statistics based on 3467 answers in 5 languages »space riddles » What are the Perseids meteor showers associated with?Comet Swift–Tuttle. In 1866, after the perihelion passage of Swift-Tuttle in 1862, the Italian astronomer Giovanni Virginio Schiaparelli discovered the link between meteor showers and comets. His findings put new light on a subject, and changed the approach of astronomers to comets. very hard 24% Comet HalleyComet Halley35%Comet Swift–TuttleComet Swift–Tuttle24%Comet Shoemaker–LevyComet Shoemaker–Levy18%Apophis AsteroidApophis Asteroid21%Created by: Ninjai. Statistics based on 2711 answers in 3 languages »universe riddles » What astronomical object emerges sometimes from supernova instead of a black hole?Magnetar. A magnetar is a type of neutron star with an extremely powerful magnetic field. The magnetic field decay powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays. As of March 2016, only 23 magnetars are known, with six more candidates awaiting confirmation.very hard 25% MagnetarMagnetar25%BlazarBlazar12%QuasarQuasar41%only a black hole can emerge from supernovaonly a black hole can emerge from supernova20%Created by: Ninjai. Statistics based on 2349 answers in 3 languages »space riddles » What is the temperature of the center of the Sun?16 million degrees Celsius. The surface temperature is only 5500 degrees Celsius.very hard 26% 16 thousand degrees Celsius16 thousand degrees Celsius18%16 million degrees Celsius16 million degrees Celsius26%16 billion degrees Celsius16 billion degrees Celsius35%16 trillion degrees Celsius16 trillion degrees Celsius18%Created by: Tschuka. Statistics based on 579 answers in 3 languages »temperatures riddles » The idea that the nascent universe passes through the phase of exponential expansion, which was driven by the positive density of vacuum energy, is called;Cosmic inflation. Alan Guth formally proposed the idea of cosmic inflation in 1981, the idea that the nascent universe passed through a phase of exponential expansion that was driven by a positive vacuum energy density (negative vacuum pressure).very hard 27% Cosmic inflationCosmic inflation27%Grand unification theoryGrand unification theory25%Theory of SupersymmetryTheory of Supersymmetry15%All answers are correct.All answers are correct.31%Created by: Tschuka. Statistics based on 4972 answers in 2 languages »physics riddles » Play astronomy quiz and see all the questions.