A
the arrangement of the solar system in which the earth sits at the center
geocentric system
God is everywhere all the time
omnipresent
a structure made for the purpose of making detailed astronomical observations
observatory
"dirty snowball" - mixture of rocks, dust, frozen water, and frozen gases
comet
the arrangement of the solar system in which the sun sits at the center
heliocentric system
never changing
Immutable
dark blotches on the sun that indicate a lower temperature than the rest of the surface
sunspots
constant stream of particles coming from the sun
cosmic rays
astronomer who proposed the theory that the sun is the center of the universe
Nicolaus Copernicus
a star that explodes
Supernova
an oval shape defined as the collection of points in which the sum of the distances from two other fixed points is the same
ellipse
the four largest moons that orbit Jupiter, discovered by Galileo
Galilean moons
the motion of a planet when it reverses the direction it travels in the night sky
retrograde motion
remains of the awesome explosion that caused a dim star to be visible for a short time
Supernova remnant
All planets orbit the sun in an ellipse, with the sun at one focus
Kepler's First Law
a distinctive shape of the moon as seen in the night sky
phase
the effect in which an object's position appears different because of the position from which it is viewed
parallax
point in an ellipse
focus
the larger the eccentricity, the more oval the ellipse
eccentricity
(in astronomy) describing the times when the earth sits between a planet and the sun
opposition