Chapter 21 Flashcards
Heliocentric
A description of the solar system in which all of the planets revolve around the sun.
Geocentric
A description of the solar system in which all the planets revolve around the Earth.
Ellipse
An elongated circle or oval shape; the shape of a planet’s orbit
Inertia
The tendency of a moving object to continue in a straight line, or a stationary object to stay in place.
Nuclear fusion
The process by which hydrogen atoms join together to form helium releasing energy.
Core
The central part of the sun where nuclear fusion occurs.
Photosphere
The inner layer of the sun’s atmosphere
Chromosphere
The middle layer of the sun’s atmosphere
Corona
The outer layer of the sun’s atmosphere
Solar wind
A stream of electrically charged particles produced by the sun’s corona.
Sun spot
A dark area of gas on the sun that is cooler than the surrounding gasses.
Solar flare
An explosion of hydrogen gas from the suns surface that occurs when loops in sunspot region suddenly connect.
Prominence
A loop of gas that protrudes from the sun’s surface.
Terrestrial planets
The name given to the four inner planets; Mercury, Venus, Earth, and Mars
Retrograde rotation
The spinning motion of a planet from east to west, opposite to the direction of most planets and moons.
Greenhouse effect
The trapping of heat by a planets atmosphere.
Gas giant
The name given to the first four outer planets; Jupiter, Saturn, Uranus, and Neptune
Comet
A ball of ice and dust whose orbit is usually a long narrow, ellipse.
Asteroid
An object that revolves around the sun that are too small and too numerous to be considered planets.
Asteroid belt
The region of the solar system between the orbits of mars and Jupiter where many asteroids are found.
Meteoroid
A chunk of rock or ice in space
Meteor
A streak of light in the sky produced by the burning of a meteoroid in earths atmosphere.
Meteorite
A meteorite that has hit earths surface.
Extraterrestrial life
Life that arises outside of earth.
