Astonomy Test Chapter two vocabulary

Term Definition
Corona The outer layer of the sun's atmosphere
Terrestrial Planets The name given to the four inner planets: Mercury, Venus, Earth, and Mars
Meteoroid A chunk of rock or dust in space
Prominence A loop of gas that protrudes from the sun's surface, linking parts of sunspot regions
Heliocentric A description of the solar system in which all of the planets revolve around the sun
Photosphere The inner layer of the sun's atmosphere
Comet A ball of ice and dust whose orbit is usually a long, narrow ellipse
Solar Wind A steam of electrically charged particles produced by the sun's corona
Solar Flares An explosion of hydrogen gas from the sun's surface that occurs when loops in sunspot regions suddenly connect
Meteor A streak of light in the sky produced by the burning of a meteoroid in the Earth's atmosphere
Ellipse An elongated circle, or oval shape; the shape of the planets' orbits
Geocentric A description of the solar system in which all of the planets revolved around Earth
Sunspot A dark area of gas on the sun that is cooler than the surrounding gases
Core The central part of the sun, where nuclear fusion occurs
Meteorite A meteoroid that has hit Earth's surface
Gas Giants The name given to the first four outer planets: Jupiter, Saturn, Uranus, and Neptune
Nuclear Fusion The process by which hydrogen atoms join together to form helium, releasing energy
Greenhouse Effect The trapping of heat by a planet's atmosphere
Chromosphere The middle layer of the sun's atmosphere
Asteroids Objects revolving around the sun that are too small and too numerous to be considered planets
Extraterrestrial Life Life that arises outside of Earth