Key Words (Stars and Planets)

• Asteroids are rocky metallic objects that orbit the sun but are too small to be considered planets.
• Black holes are at the end of a massive star's life, when the resulting core is so dense not even light can escape.
• Comets are small balls of frozen dust and rock that orbit the sun with a tail that glows.
• Fusion is the creation of energy by joining the nuclei of two hydrogen atoms to form helium.
• Galaxies are a collection of stars, dust, and gas bound together by gravity.
• The goldilocks zone is the distance from a star where life can survive on a planet as it is not too hot or too cold.
• The Hertzsprung-Russel (HR) diagram displays the properties of stars and shows the evolutionary path of a star over its lifetime.
• A light year is how far light travels in one year.
• A local group is a group of galaxies that contain the milky way.
• Main sequence stars spend the majority of their life in a state of nuclear fusion, like the sun.
• The milky way is the galaxy in which we live in.
• The moon is a natural satellite orbiting a planet.
• A nebula is a cloud of had and dust left over from the supernova death of a star.
• Neutron stars are extremely heavy and dense stars left over after a supernova.
• Planets are a large body in space that orbit a star and does not produce light on its own.
• Protostars are the formation of stars in the centre of a nebula.
• Red giants are when a stars hydrogen begins to run out of hydrogen and begins to expand by helium.
• A solar system is the local area in which we live in, consists of a star and 8 planeta plus dwarf planets and moons.
• Apart wind is a stream of charged particles that are emite by the sun.
• Solar wind is a stream of charged particles that are emite by the sun.
• Pulsar is a neutron star that emits x'-rays and gana radiation as it rotates.
• Pulsars are rotating neutron stars.
• Supernovae are the resulting explosion of a star collapsing at the end of its life.
• White dwarfs are the remaining core of a collapsed red giant when fusion is no longer happening but it gives our light due to its high temperature.