Astrophysics Crossword Puzzle

QUESTIONS LIST:

• red giant : a star that has expanded and cooled, resulting in it becoming much larger and cooler than it was before it expanded
• star : a large ball of mostly hydrogen and helium that gives out light
• fastest : the orbital speed of a comet is _ when it is closest to the sun
• dark matter : hypothesized type of mass that cannot be observed by current methods. it is used to explain why some galaxies rotate faster than they should for their observed mass.
• main sequence : the life stage of a star during which it radiates energy because of fusion of hydrogen nuclei in its core
• protostar : the first stage all stars go through after forming from a nebula. in this stage the star becomes hot enough for hydrogen nuclei to fuse.
• natural satellites : the moons that orbit planets.
• neutron star : the highly compressed core of a massive star that remains after a supernova
• black dwarf : a star that has faded out and gone cold
• red-shift : increase in the wavelength of electromagnetic waves emitted by a star or galaxy due to its motion away from us.
• red supergiant : a star much more massive than the sun will swell out after the main sequence stage to become this before it collapses
• dark energy : a hypothesised form of energy, believed to be responsible for the universe’s ever increasing rate of expansion.
• supernova : the explosion of a massive star, that d
• day : time for a planet to complete one whole rotation around its axis
• galaxy : a large group of stars orbiting a black hole
• milky way : the galaxy in which our solar system is located.
• centripetal force : the resultant force towards the centre of a circle acting on an object moving in a circular path
• black hole : an object in space that has so much mass that nothing, not even light, can escape from its gravitational field
• asteroid : small rock that orbits the sun
• ice : comets are made of rock and _
• artificial satellites : man-made objects that have been sent into space and which are in orbit around the earth
• elliptical : comets orbit the sun in highly _ paths
• big bang : the theory that the universe was created in a massive explosion, and that the universe has been expanding ever since
• nebula : a massive cloud of gas and dust