Chapter 3

Question 1

In Ptolemy’s model, it is possible to have a planetary orbit without retrograde motion

Answer 1

true

Question 2

Copernicus’ heliocentric model was able to predict the location of the planets more accurately than Ptolemy’s geocentric model

Answer 2

false

Question 3

Copernicus was the first to be able to prove that the Earth orbited around the Sun

Answer 3

false

Question 4

According to the small angle equation, if an object at a fixed distance is suddenly shrunk to a smaller size, then the angular size will

Answer 4

decrease

Question 5

Copernicus was the first person to suggest that the Sun is at the center of our solar system.

Answer 5

false

Question 6

Copernicus figure out which planets were closer to the Sun and which were further

Answer 6

sidereal and synodic periods

Question 7

Eratosthenes

Answer 7

ancient astronomer measured the radius of the Earth

Question 8

size of the Earth could be measured accurately in ancient times by using

Answer 8

shadows on Earth

Question 9

Ptolemy improved the geocentric model by

Answer 9

adding epicycles and deferents

Question 10

One of the main objections to the heliocentric model

Answer 10

we do not feel the Earth moving

Question 11

Aristotle believed that the planets

Answer 11

orbited the Earth in circular orbits

Question 12

superiod conjunction

Answer 12

When a planet orbits to the opposite side of the Sun as Earth (and it appears near the Sun in our sky), the planet is at

Question 13

sidereal period

Answer 13

The time it takes a planet to orbit the Sun once and return to the same location in space

Question 14

Ptolemy’s improvements were important because they explained

Answer 14

retrograde motion

Question 15

scientific ideas was never discussed in the ancient world

Answer 15

faint lights in the sky are galaxies

Question 16

Aristotle

Answer 16

believed the universe could be understood by the power of reason alone

Question 17

Geocentric cosmology

Answer 17

all other celestial bodies travel around the earth in circular orbits

Question 18

Small angle equation

Answer 18

θ = 206,265 * D / d

Question 19

D

Answer 19

diameter

Question 20

d

Answer 20

distance

Question 21

θ

Answer 21

angular diameter

Question 22

distance equation

Answer 22

d=206,265*D/θ

Question 23

diameter equation

Answer 23

D=θ*d/206,265

Question 24

Retrograde motion

Answer 24

some planets can reverse their steady eastward motions among the stars

Question 25

Ptolemaic model

Answer 25

requires the planets not only to move in circles around the Earth but also to move along smaller circles around imaginary points along the main circular orbits

Question 26

Epicycles

Answer 26

circle that is carried and rides around on another circle

Question 27

Epicycles

Answer 27

circle that is carried and rides around on another circle

Question 28

Heliocentric model

Answer 28

relative spacing of planets is fixed uniquely by their apparent motions

Question 29

Parallax

Answer 29

shift in angle that occurs when a nearby object is seen against a distance backdrop from two different perspectives

Question 30

Elongation

Answer 30

angle between the sun and a planet as seen by an observer on earth

Question 31

inferior planets

Answer 31

planets closer to the sun than the earth

Question 32

superior planets

Answer 32

planets further from the sun than the earth

Question 33

greatest elongation

Answer 33

inferior planets limit

Question 34

inferior conjunction

Answer 34

planet is between the sun and the earth

Question 35

superior conjunction

Answer 35

planet is on the other side of the sun as seen from earth

Question 36

opposition

Answer 36

elongation is 180 degrees

Question 37

synodic period

Answer 37

time it takes for a planet to make a complete cycle of elongation configuration

Question 38

sidereal period

Answer 38

time it takes for a planet to complete an orbit

Question 39

superior planets equation

Answer 39

1/S=1/E-1/P

Question 40

inferior planets equation

Answer 40

1/S=1/P-1/E

Question 41

E

Answer 41

1