ellipse - CORRECT ANSWER A elongated circle, or oval shape, the shape of the planets orbit.
Big Bang Theory - CORRECT ANSWER the universe began from one point billions of years ago and has
been expanding ever since
rotation - CORRECT ANSWER The spinning motion of a planet on its axis
fission - CORRECT ANSWER The splitting of an atomic nucleus to release energy
fusion - CORRECT ANSWER the process or result of joining two or more things together to form a single
entity; the process that creates energy within the sun's core
nutation - CORRECT ANSWER a small, cyclic variation of the Earth's axis of rotation with a period of 18.6
years, caused by tidal forces; Earth wobbling on its axis
precession - CORRECT ANSWER direction of the Earth's axis of rotation changes over a 26,000 yr period;
the North Celestial Pole will not always point towards the same starfield
revolution - CORRECT ANSWER The movement of an object around another object
Nebular Hypothesis - CORRECT ANSWER The idea that the sun and planets formed together from a cloud
of gas and dust, a nebula.
Kepler's 1st Law - CORRECT ANSWER planets move around the Sun in an elliptical orbit with the Sun at
one focus of the ellipse
Kepler's 2nd Law - CORRECT ANSWER The line from the Sun to a planet sweeps out equal areas in equal
times; explains where and when planets appear in the night sky