7/8th grade earth and space science Example For Students

7/8th grade earth and space science Question Answer Big Bang Theory the theory that the universe was formed about 13.7 billion years ago, from a large explosion or expansion, and is continuing to expand Galaxy a large group of stars in the universe Spiral Galaxy galaxy that is pinwheel shaped with a thin disk with long arms; gas and dust rotate around the central hub of the galaxy Elliptical Galaxy huge galaxy that is round or oval in shape Irregular Galaxy huge galaxy with no regular shape Star huge, hot body made of different gases; radiates energy (light) Nebula an immense cloud of gas (mainly hydrogen) and dust in space; where stars form light year (ly) distance light can travel in a vacuum in one year; equal to approximately 5. 87 X 10 to the power of 12 miles; the unit of measure used by astronomers to determine distances in space Planets nearly round objects that revolve around a star; in our solar system Sun medium sized star; located near edge of galaxy; many thousands of times closer to Earth than any other star; provides energy that creates convection currents in atmosphere and oceans Comet small object made of ice with some gas, dust, and rock; a tail can appear as the comet revolves around the sun and is heated Hertzsprung-Russell Diagram organizes the family of stars into a diagram; across bottom is stars temperature and side is stars absolute magnitude; a stars temperature and color depend on how big the star is Electromagnetic Spectrum increasing range in frequency of electromagnetic waves; light and radio waves are used to gain information about distances and properties of objects in the universe; ex. light years used to measure distances and sizes in the universe Phase of moon after the new moon waxing crescent Phase of moon after waxing crescent 1st quarter Phase of moon after 1st quarter waxing gibbous Phase of moon after waxing gibbous full moon Phase of moon after full moon waning gibbous Phase of moon after waning gibbous 3rd quarter Phase of moon after 3rd quarter waning cresent Phase of moon after waning crescent new moon waxing means growing waning means shrinking the force of attraction between all masses in the universe; especially the attraction of the earths mass for bodies near its surface Gravitational Attraction Lunar eclipse When the earth is between the sun and the moon Solar eclipse When the moon is between the earth and the sun The moons gravitational pull on earth causes high and low tides