PRESENTATION OUTLINE
astronomy- the scientific study of stars, planets, and other objects in outer space
eclipse- the partial or complete hiding of one celestial object by another. (An eclipse of the moon occurs when the moon orbits into Earth's shadow. An eclipse of the sun occurs when the moon's orbit takes it directly between Earth and the sun.)
astronomical unit- a unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun.
gravity- the force of attraction between objects
rotation- the spinning of Earth on its axis
revolution- when something is moving in, to circle around another object such as the way to the Moon circles the Earth
barycenter- the center of mass of two or more bodies that are orbiting each other, or the point around which they both orbit.
precession- the slow movement of the axis of a spinning body around another axis due to a torque acting to change the direction of the first axis.
nutation- a periodic oscillation of the earth's axis that causes the precession of the poles to follow a wavy rather than a circular path
electromagnetic spectrum- the range of wavelengths or frequencies over which electromagnetic radiation extends.
doppler effect- the apparent change in frequency and wavelength of energy radiated by a source as a result of the motion of the source or the observer
sunspot- a spot or patch appearing from time to time on the sun's surface, appearing dark by contrast with its surroundings.
solar flare- a brief eruption of intense high-energy radiation from the sun's surface, associated with sunspots and causing electromagnetic disturbances on the earth, as with radio frequency communications and power line transmissions.
nuclear fusion- a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy
big bang theory- the theory that the universe formed as a concentration of matter expanded explosively
