Exam I Material

Question 1

An asteroid orbits the Sun at an average distance a = 4 AU. How long does it take to orbit the Sun?

a) 4 years
b) 8 years
c) 16 years
d) 64 years

Answer 1

b) 8 years

Question 2

A result of Kepler’s “equal areas in equal times” law is _________.

a) a planet moves the same speed always
b) a planet moves slowest at aphelion
c) a planet moves fastest at aphelion
d) all planets move the same direction around the Sun
e) none of the above

Answer 2

b) a planet moves slowest at aphelion

Question 3

Star A is 5 times farther from the Earth than star B. Which has larger stellar parallax?

a) star A
b) star B
c) the stellar parallax for each one is the same
d) not enough information is given

Answer 3

b) star B

Question 4

An example of retrograde motion is when Jupiter moves _____ in the sky with respect to the stars; it occurs when Jupiter is _____ to the Earth.

a) west to east; closest
b) east to west; closest
c) west to east; farthest
d) east to west; farthest

Answer 4

b) east to west; closest

Question 5

The sidereal day is one rotation of the Earth relative to the ____, while the solar day is one rotation of the Earth relative to the ____. The ____ day is longer by 4 minutes.

a) Sun; stars; solar
b) Sun; stars; sidereal
c) stars; Sun; solar
d) stars; Sun; sidereal

Answer 5

c) stars; Sun; solar

Question 6

The angular distance of a place north or south of the equator (parallels).

Answer 6

latitude

Question 7

The angular distance of a place east or west of the prime meridian (meridians).

Answer 7

longitude

Question 8

A circle on the surface of a sphere that lies in a plane passing through the sphere’s center.

Answer 8

great circle

Question 9

An imaginary great circle passing through the poles and the royal observatory in Greenwich England.

Answer 9

prime meridian

Question 9

Positioned in or relating to the sky or outer space.

Answer 9

celestial

Question 9

An imaginary sphere of which the observer is the center and on which all celestial objects are considered to lie.

Answer 9

celestial sphere

Question 9

A recognizable pattern in the night sky.

Answer 9

constellation

Question 10

A prominent pattern or group of stars typically having a popular name.

Answer 10

asterism

Question 10

Of or with respect to the distant stars.

Answer 10

sidereal

Question 11

Of or resulting from the daily rotation of the Earth.

Answer 11

diurnal

Question 12

Astronomical latitude; measured north or south of the celestial equator.

Answer 12

declination

Question 13

Astronomical longitude; measured in hours along the celestial equator.

Answer 13

right ascension

Question 14

Inclined at an angle that is not a right angle or parallel.

Answer 14

oblique

Question 15

LST

Answer 15

local sidereal time

Question 16

The science of the origin and development of the universe.

Answer 16

cosmology

Question 17

A star (or motion) above the horizon at all times in a given latitude.

Answer 17

circumpolar

Question 18

A celestial body moving in an elliptical orbit around a star.

Answer 18

planet

Question 19

Proceeding from west to east (of planetary motion).

Answer 19

prograde

Question 20

A reverse direction from normal.

Answer 20

retrograde

Question 21

The angle observed from the Earth between the direction of the Sun and the direction to a planet.

Answer 21

elongation

Question 22

An elongation of 0 degrees (co-linear with the Earth and the Sun).

Answer 22

conjunction

Question 23

An elongation of 180 degrees (co-linear with the Earth and the Sun).

Answer 23

opposition

Question 24

An observed shift in a star's apparent position resulting from the Earth's motion around the Sun.

Answer 24

stellar parallax

Question 25

The apparent motion of a star across the celestial sphere at right angles to the observer's line of sight.

Answer 25

proper motion

Question 26

Movement toward or away from the Sun.

Answer 26

radial motion

Question 27

The point of greatest or least distance of a body from one of the foci of its elliptical orbit.

Answer 27

apsis

Question 28

The point in the path of an orbiting body at which it is nearest to the body that it orbits.

Answer 28

periapsis

Question 29

The point in the path of an orbiting body at which it is furthest from the body that it orbits.

Answer 29

apoapsis

Question 30

A property of matter by which it continues in its existing state if rest or uniform motion in a straight line unless that state is changed by an external force.

Answer 30

intertia

Question 31

Moving in a geosynchronous orbit in the plane of the equator so that it remains stationary in relation to a fixed point on the surface.

Answer 31

geostationary

Question 32

By locating the north celestial pole (NCP) in the sky, how can you determine your latitude? a) the altitude of the NCP is the same as your latitude b) the altitude of the NCP is your angular distance from the North Pole c) the azimuth of the NCP is the same as your latitude d) the azimuth of the NCP is the angular distance from the North Pole e) the altitude of the NCP is the same as your distance from the North Pole

Answer 32

a) the altitude of the NCP is the same as your latitude

Question 33

Why is it summer in the Northern Hemisphere when it is winter in the Southern Hemisphere? a) the Northern Hemisphere is closer to the Sun than the Southern Hemisphere b) the Northern Hemisphere is "on top" of Earth and therefore receives more sunlight c) the Northern Hemisphere is tilted toward the Sun and receives more direct sunlight d) the Northern Hemisphere is tilted away from the Sun and receives more indirect sunlight e) it isn't: both hemispheres have the same seasons at the same time

Answer 33

c) the Northern Hemisphere is tilted toward the Sun and receives more direct sunlight

Question 34

Which of the following statements about the celestial equator is true at all latitudes? a) it lies along the band of light we call the Milky Way b) it represents an extension of Earth's equator onto the celestial sphere c) it cuts the dome of your sky exactly in half d) it extends from your horizon due east, through your zenith, to your horizon due west e) it extends from your horizon due north, through your zenith, to your horizon due south

Answer 34

b) it represents an extension of Earth's equator onto the celestial sphere

Question 35

What is the hour angle of a star crossing your meridian? a) -6 hours b) 0 hours c) 6 hours d) it depends on your latitude e) it depends on the right ascension of the star

Answer 35

b) 0 hours

Question 36

Which of the following correctly describes the meridian in your sky? a) a half-circle extending from your horizon due east, through your zenith, to your horizon due west b) a half-circle extending from your horizon due north, through your zenith, to your horizon due south c) a half-circle extending from your horizon due east, through the north celestial pole, to your horizon due west d) the point directly over your head e) the boundary between the portion of the celestial sphere you can see at any moment and the portion that you cannot see

Answer 36

b) a half-circle extending from your horizon due north, through your zenith, to your horizon due south

Question 37

Which of the following best describes the modern definition of a constellation? a) a region of the celestial sphere b) a pattern of bright stars in the sky c) a Greek mythological figure d) a collection of stars that are near one another in space e) a group of stars that all lie at about the same distance from Earth

Answer 37

a) a region of the celestial sphere

Question 38

What is the ecliptic? a) when the Moon passes in front of the Sun b) the Moon's apparent path along the celestial sphere c) the constellations commonly used in astrology to predict the future d) the Sun's daily path across the sky e) the Sun's apparent path along the celestial sphere

Answer 38

e) the Sun's apparent path along the celestial sphere

Question 39

The fact the Orion is a constellation of our winter sky and is not visible on a summer evening is due to: a) the Earth’s rotation on its axis b) the Earth’s revolution around the Sun c) the Earth’s precession d) Orion being at the north celestial pole

Answer 39

b) the Earth’s revolution around the Sun

Question 40

Stars that never appear to set are called circumpolar. As you move from Earth’s equator toward the North Pole, the number of stars that are circumpolar: a) increases b) decreases c) stays the same d) all stars are circumpolar

Answer 40

a) increases

Question 41

Ptolemy introduced epicycles to explain _______________. a) stellar motions b) the seasons c) the phases of the Moon d) eclipses e) retrograde motion of planets

Answer 41

e) retrograde motion of planets

Question 42

Once a planet’s sidereal period is know, you can use Kepler’s 3rd law to determine __________________. a) the planet’s distance (semi major axis) from the Sun b) the planet’s orbital speed c) the planet’s rotational speed d) the planet’s orbital direction

Answer 42

a) the planet’s distance (semi major axis) from the Sun

Question 43

Which of the following planets never reaches opposition as seen from the Earth? a) Venus b) Mars c) Jupiter d) Neptune e) they all reach opposition

Answer 43

a) Venus

Question 44

The time between rising and setting of a star: a) is always 12 hours b) depends on the star's declination c) depends on the star's right ascension d) depends on the observer's latitude e) depends on the observer's longitude

Answer 44

d) depends on the observer's latitude

Question 45

Suppose you live at latitude 40°N. Which of the following describes the path of the celestial equator through your sky? a) it goes from due south on your horizon, to your zenith, to due north on your horizon b) it goes from due east on your horizon, to your zenith, to due west on your horizon c) it goes from due east on your horizon, to an altitude of 50° in the south, to due west on your horizon d) it goes from due east on your horizon, to an altitude of 40° in the south, to due west on your horizon e) it goes from due east on your horizon, to an altitude of 40° in the north, to due west on your horizon

Answer 45

c) it goes from due east on your horizon, to an altitude of 50° in the south, to due west on your horizon

Question 46

Suppose you live at latitude 40°N. Which of the following describes the conditions that make a star circumpolar? a) stars are circumpolar if they have declination > +50° b) stars are circumpolar if they have declination > +40° c) stars are circumpolar if they have right ascension > 6 hr d) stars are circumpolar if they have right ascension < 6 hr e) no stars are circumpolar at this latitude

Answer 46

a) stars are circumpolar if they have declination > +50°

Question 47

Suppose the date is March 21 and the Sun passes through your zenith at noon. Where are you? a) the equator b) the Tropic of Cancer c) the Tropic of Capricorn d) the Arctic Circle e) the Antarctic Circle

Answer 47

a) the equator

Question 48

The Sun is on your meridian, and you have a UT clock that tells you it is 3 P.M. in Greenwich. What is your longitude? a) 3° west of Greenwich b) 3° east of Greenwich c) 45° west of Greenwich d) 45° east of Greenwich e) 30° west of Greenwich

Answer 48

c) 45° west of Greenwich

Question 49

Saturn is closest to the Earth at ______________. a) conjunction b) greatest elongation c) quadrature d) opposition

Answer 49

d) opposition

Question 50

______ was the first to observe Jupiter’s moons, Saturn’s rings, phases of Venus, and sunspots.

Answer 50

galileo

Question 51

______ determined a scale size of the Solar System based on a heliocentric model, and determined sidereal periods for all the planets (that were known in his/her time).

Answer 51

copernicus

Question 52

______ was the first to make a reasonably accurate estimate of the Earth’s size.

Answer 52

erastosthenes

Question 53

______ observe planetary positions with sufficient accuracy so that _______ could later use the data to discover the laws of planetary motion.

Answer 53

brahe; kepler