Chapter 3 - The Science of Astronomy

Question 1

List Kepler’s laws of planetary motion

Answer 1

1) the orbit of each planet around the Sun is an ellipse with the Sun at one focus
2) as a planet moves around its orbit, it sweeps out equal areas in equal times
3) more distant planets orbit the Sun at slower average speeds, obeying a precise mathematical relationship (that is p^2 = a^3 where p is the orbital period in years and a is its average distance from the Sun in AU)

Question 2

Prime focus of a reflecting telescope

Answer 2

The first point at which light focuses after bouncing off the primary mirror; located in front of the primary mirror.

Question 3

Paradigm (in science)

Answer 3

A general pattern of thought that tends to shape scientific study during a particular time period.

Question 4

Ptolemaic model

Answer 4

The geocentric model of the universe developed by Ptolemy in about 150 a.d.

Question 5

Aphelion

Answer 5

The point at which an object orbiting the Sun is farthest from the Sun

Question 6

Deferent

Answer 6

The large circle upon which a planet follows its circle-upon-circle path around Earth in the (Earth-centered) Ptolemaic model of the universe.

Question 7

Geocentric model

Answer 7

Any of the ancient Greek models used to predict planetary positions under the assumption that Earth lay in the center of the universe.