Astronomy Vocab 1

Which of the following best describes the term revolution as it pertains to Astronomy?

• spinning like a basketball spinning on someone’s finger

• the earth spins and this causes the day/night cycle

• Mars appears to go backwards in the sky

• spinning around an external axis

This causes a ball to drop to the ground on earth as well as the orbits of the planets around the sun.

• momentum

• inertia

• gravity

• circular motion

Which of the following best defines a closed orbit?

• an orbit that never ends

• an orbit which returns to its starting point

• an orbit in which no other object can enter

• an orbit that does not repeat itself

This ideology was proposed to explain the motions of celestial bodies and put earth in the center of the universe

• Earthcentrism

• Earthisbestism

• Heliocentrism

• Geocentrism

Copernicus developed a model which put the sun at the center of our universe, often coined

• Geocentrism

• Heliocentrism

• Eccentricity

• Ellipses

axis is half of the distance between the two farthest points on the circumference of an ellipse (2 words, no hyphen)

a small circle with a center moving around the edge of a larger circle; Ptolemy used these to explain the weird motion of Mars

Not quite a circle, but a “squashed” circle; similar to an oval

used to explain planetary orbits; a point in which a planet sweeps out equal angles along its orbit at equal times

how far from circular something is; used to describe the orbit of planets, for instance, which are not exactly circular