AST 220 Midterm Exam Questions with
Answers 100% Solved
umbra The darkest part of a shadow
waning becoming less bright, intense, or strong; getting smaller
waxing (of the moon) pertaining to the period during which the visible surface of the
moon increases
zenith The point directly overhead, which has an altitude of 90 degrees.
zodiac the constellations on the celestial sphere through which the ecliptic passes.
aphelion the point at which an object orbiting the sun is farthest from the sun
copernican revolution The dramatic change, initiated by copernicus, that occurred when
we learned that Earth is a planet orbiting the Sun rather than the center of the universe
ellipse A type of oval that happens to be the shape of bound orbits.
, geocentric model Any of the ancient Greek models that were used to predict planetary
positions under the assumption that Earth lay in the center of the universe.
hypothesis A tentative model proposed to explain some set of observed facts, but which
has not yet rigorously tested and confirmed
kepler's laws of planetary motion Three laws discovered by Kepler that describe the
motion of the planets around the sun.
model A representation of some aspect of nature that can be used to explain the predict
real phenomena without invoking myth, magic, or the supernatural.
occam's razor prefer the simpler method
perihelion The point at which an object orbiting the sun is closest to the sun.
ptolemaic model The geocentric model of the universe developed by Ptolemy in about
150 AD
semimajor axis Half the distance across the long axis of an ellipse; in this text, it is
usually refered to as the average distance of an orbiting object, abbreviated a in the formula for
kepler's third law.
Answers 100% Solved
umbra The darkest part of a shadow
waning becoming less bright, intense, or strong; getting smaller
waxing (of the moon) pertaining to the period during which the visible surface of the
moon increases
zenith The point directly overhead, which has an altitude of 90 degrees.
zodiac the constellations on the celestial sphere through which the ecliptic passes.
aphelion the point at which an object orbiting the sun is farthest from the sun
copernican revolution The dramatic change, initiated by copernicus, that occurred when
we learned that Earth is a planet orbiting the Sun rather than the center of the universe
ellipse A type of oval that happens to be the shape of bound orbits.
, geocentric model Any of the ancient Greek models that were used to predict planetary
positions under the assumption that Earth lay in the center of the universe.
hypothesis A tentative model proposed to explain some set of observed facts, but which
has not yet rigorously tested and confirmed
kepler's laws of planetary motion Three laws discovered by Kepler that describe the
motion of the planets around the sun.
model A representation of some aspect of nature that can be used to explain the predict
real phenomena without invoking myth, magic, or the supernatural.
occam's razor prefer the simpler method
perihelion The point at which an object orbiting the sun is closest to the sun.
ptolemaic model The geocentric model of the universe developed by Ptolemy in about
150 AD
semimajor axis Half the distance across the long axis of an ellipse; in this text, it is
usually refered to as the average distance of an orbiting object, abbreviated a in the formula for
kepler's third law.
