What happens when a protostar fails to reach the critical mass and internal temperature needed to initiate nuclear fusion? It explodes into a supernova false It becomes a brown dwarf true It becomes a white dwarf false It becomes a black dwarf false Single What is the name of the spacecraft that made humanity's first soft landing on a comet? Rosetta false Philae true Stardust false Vega false Single What is the term used to refer to the critical amount of matter necessary for the initiation of runaway accretion? Schwarzchild radius false Jean's Mass true Hill Sphere false Gravitational constant false Single Which isotopes need to be fused to produce an atom of helium? two deuterium atoms false two tritium atoms false one atom each of tritium and deuterium true two hydrogen ions false Single Where is the Kuiper Belt located? Beyond the Oort Cloud false Beyond the orbit of Neptune true Between the orbits of Mars and Jupiter false Within the orbit of Mercury false Single How many percent of the mass of the protoplanetary disk was consumed to form the Sun? 10% false 25% false 50% false 99% true Single Which Kuiper Belt Objects did the New Horizons space probe visit? Triton and Pluto false Pluto and Quaoar false Pluto and Arrokoth true Pluto and Eris false Single The currently-accepted version of the Solar Nebular Theory was formulated by which scientist? Immanuel Kant false Pierre Simon de Laplace false George Gamow false Viktor Safronov true Single Which is the name of the first exoplanet to be discovered? Dimidium true Brahe false Finlay false Hypatia false Single The dating of which material helped determine the age of the Solar System? meteorites true solar wind false Kuiper belt samples false near-Earth asteroids false Single