NAME _______________________________________________

Astronomy 121
Test 1

Write your name on the test and the Scantron form. Write your student ID number in the appropriate area and bubble in the appropriate numbers on the Scantron form.
When you finish the exam, turn in the test and the Scantron form at the front desk.

Multiple Choice Questions (50 questions--2 points per question). Select the best answer.

1. The first great observational astronomer was ___ .
a. Galileo
b. Copernicus
c. Tycho Brahe
d. Johannes Kepler
e. Issac Newton
2. The Heliocentric model for the Solar System was first proposed by _ .

a. Galileo
b. Copernicus
c. Kepler
d. Erastosthenes
e. Aristarchus

3. Of the following planets, which goes through the full set of phases in a cycle similar to that exhibited by the Moon?

a. Uranus
b. Venus
c. Mars
d. Jupiter
e. All of the above go through a full set of phases like the Moon.
4. Copernicus adopted the Heliocentric theory because _ .

a. new, more accurate observations favored the Heliocentric model over the Geocentric model
b. annual trigonometric parallax was finally detected in 1500
c. the Universe was discovered to be much larger than previously thought
d. the laws of physics, as understood in his day, indicated that the Heliocentric model was correct
e. Copernicus found it aesthetically pleasing
5. Of the following, which was the greatest contribution to modern thinking made by the Greeks?

a. They showed that the planets orbited about the Sun.
b. Their rich mythology served as the basis for the naming of constellations.
c. Their ability to make precise astronomical observations.
d. Their development of scientific inquiry and model building.
e. Their strong belief in mysticism as the explanation for why things happen in the universe.

6. Yesterday I went outside and saw star Z rise at precisely 10 p.m. One month ago, when did star Z rise?
a. at 8 p.m.
b. at 6 p.m.
c. at midnight
d. around 10 p.m.
e. at 2 a.m.
7. The Terrestrial planets are _ .

a. Mercury, Jupiter, and Uranus
b. Jupiter, Uranus, Neptune, and Pluto
c. Mercury, Earth, Venus, and Mars
d. Jupiter, Saturn, Neptune, and Uranus
e. Saturn, Pluto, Jupiter, Uranus, and Neptune

8. High tide occurred around sunset yesterday. What was the rough phase of the Moon?

a. new
b. first quarter
c. full
d. third quarter

9. Protoplanets form from _ .

a. the collision and coalescence of dust particles
b. the merging of planetesimals
c. the capture of gas from the Solar Nebula by dust particles
d. the capture of gas from the Solar Nebula by planetesimals

10. Which statement about the day is FALSE

a. The sidereal day is based on the Earth's rotation with respect to the stars.
b. The Solar day is based on consecutive crossings of the meridian by the Sun.
c. Normal timekeeping is based on the Solar day.
d. The sidereal day is four minutes longer than the Solar day.
e. The difference between the Solar day and the sidereal day arises because the Earth orbits about the Sun.

11. The Moon is third quarter. When will the Moon appear highest in the sky?
a. noon
b. sunset
c. midnight
d. sunrise
e. It depends on the season.

12. Venus evolved so that its surface temperature is now 800-900 F, while the Earth evolved so that its average surface temperature is now ~70 F. The explanation for this is that _ .
a. Liquid oceans formed on the Earth but not on Venus, because Venus is closer to the Sun than is the Earth.
b. Venus formed with no water, while the Earth had plentiful water at birth
c. Venus did not have a protective Ozone layer in contrast to the current Earth
d. The polar ice caps on Earth reflected sunlight efficiently; Venus did not have polar ice caps
e. A large comet struck Venus just after it formed causing Venus to heat to its current high temperature

13. As viewed from the the Earth, Mars exhibits retrograde episodes _ .

a. that recur on the synodic period, roughly 2.1 years
b. that recur on the sidereal revolution period of the Earth, that is, every year
c. that recur on the sidereal revolution of Mars, that is, every 1.88 years
d. that recur randomly; they are unpredictable
e. that recur every year except for leap years

14. The path the Sun follows through the stars is _ .

a. called the line-of-nodes
b. known as the ecliptic
c. referred to as the Saros cycle
d. parallel to the Celestial Eqauator
e. exhibits retrograde episodes every leap year

15. In an eclipse, the darkest part of the Moon's shadow is the _ .

a. umbra
b. annulus
c. penumbra
d. equinox
e. nadir
16. What day of the year has the most hours of daylight for an observer in Eugene?

a. the summer solstice
b. the winter solstice
c. the vernal equinox
d. the autumnal equinox
e. January 1
17. The period of the seasonal variations is the _.
a. sidereal year
b. synodic month
c. tropical year
d. Saros cycle
e. diurnal cycle
18. The Greek credited with taking the Geocentric model to its pinnacle is _ .

a. Aristotle
b. Aristarchus
c. Erastosthenes
d. Ptolemy
e. Hipparcos

19. Comparative planetology _ .

a. helps us to understand the physics of the Earth
b. helps us to understand how the Solar System formed
c. helps us to learn which planets are suitable for life as we know it
d. helps us to understand planetary physics
e. All of the above are true.

20. The _ is a measure of the strength of gravity at the surface of a planet or a Moon.

a. atmospheric pressure
b. composition of the planet
c. escape speed
d. orbital period
e. rotational period

21. If a total Solar eclipse occurred 3 weeks ago, what is the approximate phase of the Moon today?

a. new
b. first quarter
c. full
d. third quarter
e. waxing or waning gibbous

22. The daily paths of stars for an observer situated at the North Pole of the Earth are best described as ___ .
a. circles inclined at an angle of 23.5^o to the horizon
b. circles centered on the zenith of the observer
c. ellipses that make angles of 45^o with the horizon
d. semi-circles centered on the East point on the horizon
e. semi-circles centered on the north point on the horizon

23. The cause of the seasonal variations in Eugene is _ .
a. the varying distance of the Earth from the Sun
b. the variation in the length of the Solar Day
c. the raising and lowering of the tides by the Moon
d. the variation in the directness (angle) with which sunlight strikes the ground
e. the local topography in the Eugene area
24. Of the following items, which one need NOT be explained directly by models for the formation of the Solar System?

a. The planets all orbit about the Sun in the same sense.
b. The existence of Terrestrial, Jovian, and Icy planets
c. The composition of the Jovian planets
d. The unusual composition of Mercury
25. The Earth travels fastest in its orbit in January, when it is the closest to the Sun. This can be understood through an application of _ .
a. Kepler's law of ellipses
b. Kepler's law of equal areas
c. Kepler's harmonic law
d. a combination of Kepler's law of ellipses and the harmonic law
e. a combination of the Keplers law of ellipses and the law of equal areas

26. Retrograde motion is _ .
a. the reversal of the Sun's motion through the stars at the solstices
b. the reversal of the motion of a planet through the stars
c. the switching of the hours of daylight and darkness on the equinoxes
d. the shifting of a star's position due to the revolution of the Earth about the Sun

27. The key to understanding the large difference between the Jovian planets and the Terrestrial planets is _ .
a. noting that water was able to exist in solid form (ice) starting around the orbits of the Jovian planets
b. noting that the outer Solar System contains more hydrogen than does the inner Solar System
c. the ability of rocky material to be in solid form only around the orbits of the Jovian planets
d. that there was no gas in the inner Solar System
e. We do not understand why the Jovian planets are so different from the Terrestrial planets.
28. Which concept is not a part of Kepler's Laws of Planetary Motion?

a. All planetary orbits are ellipses.
b. The square of the planet's orbital period is equal to the cube of its average distance from the Sun.
c. A planet moves the fastest in its orbit at perihelion.
d. Epicycles are needed to explain the varying brightnesses of the planets.
e. The line that connects the planet and the Sun sweeps out equal areas in equal times.

29. Kepler's third law of planetary motion says that __ .
a. a planet moves more rapidly in its orbit when near the Sun than when it is far from the Sun
b. the Sun sits at the center of planetary orbits
c. slow moving planets are closer to the Sun than are fast moving planets
d. planets close to the Sun have shorter orbital periods than those far from the Sun
e. retrograde episodes occur every sidereal revolution period
30. The currently accepted theory for the origin of the Moon postulates that the young Earth was struck by a Mars-sized object which led to the formation of the Moon. This scenario is supported by _ .

a. the similarity of the average density of the Moon to the density of rocks found in the Earth's crust
b. the relative scarcity of volatile materials in the Moon
c. the spherical shape of the Moon
d. only a and b
e. a, b, & c
31. Eclipses occur _ .

a. every month at new Moon
b. every two weeks at the quarter Moon phases
c. every month at full Moon
d. roughly every six months
e. once a year at the first new Moon

32. An observer sees half of the Celestial Sphere over the course of a year. At which of the following locations does he or she live?
a. the North Pole
b. Eugene, OR (or near Eugene, OR)
c. the equator
d. near Santiago, Chile (latitude = 30^o S)
e. any of the above sites.

33. Of the following objects which goes through the full cycle of phases in a manner similar to the phases shown by the Moon?

a. Uranus
b. Venus
c. Mars
d. Jupiter
e. All of the above go through a full set of phases like the Moon.
34. The chemical composition of Jupiter and Saturn is most similar _ .
a. to that of the Sun
b. to that of Venus
c. to that of the Earth
d. to that of Mars
e. to that of Mercury

35. The daily motion of celestial objects is caused by _ .
a. the Earth's revolution about the Sun.
b. the Earth's rotation on its axis.
c. the motion of the Moon about the Earth.
d. the precession of the Earth's axis of rotation.

36. On the Autumnal Equinox, the Sun _ .
a. reaches its farthest point south of the Celestial equator
b. crosses the Celestial equator moving northward
c. reaches its highest point north of the Celestial equator
d. crosses the Celestial equator moving southward
e. circles parallel to the horizon for an observer at the equator

37. Compared to the Terrestrial planets, Jovian planets are, on average, _ .
a. more dense and more massive
b. less dense and more massive
c. more dense and less massive
d. less dense and less massive
38. Which of the following is a characteristic of the Terrestrial planets?

a. They exhibit a very wide range of densities, 0.1 gram per cubic centimeter to more than 10 grams per cubic centimeter.
b. They are composed of rocky material and are much more massive than are the Jovian planets.
c. They have small diameters compared to the Jovian planets.
d. They all have massive carbon dioxide atmospheres.
e. All of the above are characteristics of the Terrestrial planets.

39. Which of the following is a FALSE statement about the motions of the planets?
a. The planets move through the Zodiac constellations, usually in the west-to-east direction.
b. Only the planets whose orbits are larger in size than that of the Earth exhibit retrograde motion
c. The planets orbit roughly in the ecliptic plane.
d. Only planets whose orbits are smaller in size than that of the Earth exhibit a new phase for observers on or near the Earth.
e. The planets rise in the east and set in the west, even when they undergo retrograde motion.

40. What factor explains the formation of the distinct types of planets, the Terrestrials, Jovians, and Icy planets found in our Solar System?

a. The spin (angular momentum) of the forming planet
b. The amount of dust particles in the Solar Nebula
c. The variation in the temperature of the Solar Nebula
d. All of the above
e. None of the above

41. What phenomenon accounts for the 26,000 year wobble which shifts the location of the North Celestial Pole among the stars?

a. rotation
b. revolution
c. precession
d. the tides

42. According to Copernicus, retrograde motion _ .
a. could only be understood if the stars were very close to the Earth
b. was due to the epicyclic motion of the planet
c. would occur when a faster moving inner planet caught up and passed a slower moving outer planet
d. occurred because of the slow drift of the Earth's rotation axis caused by precession
e. could not be easily understood in a heliocentric model

43. Terrestrial planets formed from the coalescence of _ .
a. large asteroids
b. gases in the Solar Nebula
c. planetesimals and then protoplanets
d. minor bodies, such as comets and asteroids
e. small random objects, such as moons and debris from the outer Solar System
44. The density of a planet gives strong clues to the _ .
a. age of the planet
b. sidereal day of the planet
c. chemical composition of the interior of the planet
d. chemical composition and mass of the atmosphere of the planet
e. existence of tides on the planet

45. Which of the following planets has a ring system?
a. Jupiter
b. Saturn
c. Uranus
d. Neptune
e. All of the above planets have ring systems
46. Morning and evening stars are not stars. They are _ .
a. actually comets
b. the Moon, just before a Lunar eclipse
c. actually only the Sun when it is near the Vernal Equinox
d. the planets Mercury and Venus
e. Wait, the morning star is Mercury and the evening star is Venus

47. What important event occurred when the Sun turned-on and developed an intense Solar Wind (its T Tauri phase)?
a. Jupiter collided with a large Mars-like planetesimal producing Venus.
b. The Earth developed free oxygen in its atmosphere.
c. Dust rapidly formed signaling the start of planet formation.
d. The planet formation process ended.
e. Protoplanets started to form from planetesimals

48. What role is played by the irregularities in the Solar System in terms of theories of the formation of the Solar System?

a. They are too minor to play a role; astronomers ignore them.
b. They don't affect the fundamental model, but do require that theories be flexibile enough to account for irregularities
c. Theories for the formation of the Solar System are based entirely on the irregularities found among the planets.
d. The Solar System has no irregularities; it is perfect in form.

49. As the Solar Nebula contracted, ___ .

a. it spun faster and flattened as it shrank
b. it spun faster and shed rings of material as it shrank
c. it cooled forming a solid, spinning disk made of rocky materials
d. its spin caused dense materials to sink toward the rotation axis and light materials to float

50. If an object were abundant in refractory elements, but had few volatile elements, which of the following is the most likely (simplest) explanation?

a. The object was formed in a region of low temperature
b. The object was formed in a region of high temperature
c. The object was formed in a region which was first hot, then cold, then hot, and then cold again
d. The object was formed in the Sun and then ejected into the Solar System