10 most difficult astronomy riddles A list of ten (out of 133) astronomy related questions that are the most often answered incorrectly Astronomy quiz 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 8% ArcturusArcturus12%CanopusCanopus8%VegaVega72%ProcyonProcyon8%Created by: Ninjai. Statistics based on 25 answers in 2 languages »stars riddles » 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.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 4144 answers in 2 languages »weapons 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 18% In the TroposphereIn the Troposphere22%In the StratosphereIn the Stratosphere38%In the mesosphereIn the mesosphere21%In the ThermosphereIn the Thermosphere18%Created by: Tschuka . Statistics based on 738 answers in 2 languages »atmosphere 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 18% 16 thousand degrees Celsius16 thousand degrees Celsius21%16 million degrees Celsius16 million degrees Celsius18%16 billion degrees Celsius16 billion degrees Celsius36%16 trillion degrees Celsius16 trillion degrees Celsius22%Created by: Tschuka . Statistics based on 410 answers in 3 languages »temperatures 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 19% 100 000 thousand light years100 000 thousand light years19%200 000 thousand light years200 000 thousand light years26%500 000 thousand light years500 000 thousand light years32%1 000 000 thousand light years1 000 000 thousand light years21%Created by: Tschuka . Statistics based on 424 answers in 2 languages »numbers 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 23% MagnetarMagnetar23%BlazarBlazar12%QuasarQuasar43%only a black hole can emerge from supernovaonly a black hole can emerge from supernova21%Created by: Ninjai. Statistics based on 2067 answers in 3 languages »space 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 1514 answers in 3 languages »space riddles » Which of Saturn's natural satellites has such distinctive equatorial ridge?Iapetus. The ridge is 13 km high, 20 km wide and 1300 km long. Its origin is not known, but considering the amounts of craters it's safe to assume that this is a very old geological creation.very hard 24% DioneDione12%RheaRhea29%EnceladusEnceladus34%IapetusIapetus24%Created by: Ninjai. Statistics based on 2314 answers in 2 languages »planets 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 dwarf2%Red dwarfRed dwarf50%Created by: Tschuka . Statistics based on 3267 answers in 4 languages »space riddles » The celestial sphere is divided into ...88 constellations. The current list of 88 constellations recognized by the International Astronomical Union since 1922 is based on the 48 listed by Ptolemy in his Almagest in the 2nd century, with early modern modifications and additions In 1930, the boundaries between the 88 constellations were devised by Eugène Delporte along vertical and horizontal lines of right ascension and declination.very hard 26% 22 constellations22 constellations16%44 constellations44 constellations32%66 constellations66 constellations24%88 constellations88 constellations26%Created by: Tschuka . Statistics based on 1469 answers in 2 languages »universe riddles » Play astronomy quiz and see all the questions.