NAME _______________________________________________
Astronomy 121
MW class
Test 1
February 8, 2006
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. In ancient times, people observed the heavens because _____ .
a. learning the constellations served as a rite of passage for adulthood
b. they were looking for "ancient astronauts"
c. the motions of celestial objects served as clocks
d. they believed that gods inhabited the celestial realm
2. The Greeks surmissed that the Earth was spherical in shape because _______ .
a. the shadow cast by the Moon during total Solar eclipses was curved
b. the full Moon was round
c. the seasons reversed when going from the northern to southern
hemispheres
d. objects always rolled toward the equator
e. the appearance of the sky changed as an observer
moved north or south on the Earth
3. Yesterday I went outside and saw star Z rise at precisely 10 p.m.
Two weeks from now, when will star Z rise?
a. around 8 p.m.
b. around 9 p.m.
c. around midnight
d. around 10 p.m.
e. around 11 p.m.
4. Our understanding of the Solar System can best be described as: _____ .
a. Slow and steady improvements for many centuries
b. Erratic; it was driven by the birth of eccentric geniuses
c. Steady until the last few decades when, with the decline of the space program, we have learned
very little
d. We have learned more in the past few decades than during all of previous history
5. Which of the following is a characteristic of the
Terrestrial planets?
a. They exhibit a very wide range of densities, 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 Jovian planets.
c. They have small diameters compared to Jovian planets.
d. They have massive carbon dioxide atmospheres.
e. All of the above are characteristics of the Terrestrial planets.
6. The chemical composition of the atmospheres of the Jovian planets 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
7. Of the following, which is a correct statement about the Jovian planets?
a. The atmospheres of the Jovian planets are composed primarily of
nitrogen and oxygen
b. All Jovian planets exhibit orbital irregularities
c. All Jovian planets all have low densities, densities
around 1 gram per cubic centimeter
d. Jovian planets do not orbit about the Sun; they orbit about
the North Celestial Pole
e. No Jovian planet has an extensive satellite system
8. Which of the following is not a characteristic of the
Terrestrial planets?
a. They have high density
b. They have solid outer layers (hard surfaces)
c. They have small diameters
d. They orbit very far from the Sun (more than 10 A.U.)
e. They do not have ring systems
9. 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
e. the Sun's motion through the stars
10. The density of the Moon is most similar to _____ .
a. the density of the Sun
b. the density of Jupiter
c. the density of the center of the Earth
d. the density of the rocks in the crust of the Earth
e. the density of Pluto
11. On the winter solstice, the Sun _______ .
a. crosses the Celestial equator moving southward
b. crosses the Celestial equator moving northward
c. the shortest day of the year occurs
d. reaches its furthest point south of the Celestial equator
e. circles parallel to the horizon for an observer at the equator
12. Tycho Brahe's principal contribution to astronomy was _____ .
a. the observation of annual trigonometric parallax
b. his novel model for the Solar System
c. the accuracy and completeness of his observational records
d. his observation of sunspots
e. the discrovery of the rings of Saturn
13. The environmental variable of the Solar Nebula that determined
why the different classes of planets formed is _____ .
a. the temperature and how it varied in the Solar Nebula
b. the chemical composition of the Solar Nebula
c. the spin of the Solar Nebula where Jupiter formed
d. the shape of the Solar Nebula
e. the amount of hydrogen contained in the Solar Nebula near Juptier
14. A key to understanding how the large difference between
the Jovian planets and the Terrestrial planets arose was _____ .
a. noticing that water could exist in solid form (ice) starting around the
orbit of Jupiter
b. noticing that the outer Solar System contained more hydrogen
than did the inner Solar System
c. the observation that rocky material could be in solid form only around
the orbit of Jupiter
d. observation that was no gas in the inner Solar System
e. We do not understand why the Jovian planets are so different
from the Terrestrial planets.
15. Precession _____ .
a. causes the slow conical motion of the Earth's rotation axis
b. leads to the apparent backward motion of the planets on the sky
c. caused the rotation axis of Uranus to lie roughly in the ecliptic plane
d. is a measure of the amount of mass in planet's atmosphere
e. raises the tides on the Earth
16. Compared to the Jovian planets, Terrestrial 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
e. more dense but have roughly the same masses
17. What important event occurred while the Sun was in its T Tauri
phase (the phase when the young Sun developed an intense Solar Wind)?
a. Jupiter collided with a large Mars-like planetesimal.
b. The Earth developed free oxygen in its atmosphere.
c. The planet formation process was essentially halted.
d. The Sun deposited large amounts of dust into the Solar Nebula initating
the planet formation process.
e. Protoplanets started to coalesce out of the planetesimals.
18. The heliocentric theory for the Solar System was first
proposed by _____ .
a. Aristotle
b. Aristarchus
c. Ptolemy
d. Copernicus
e. Galileo
19. Of the following, what is the most valuable indicator
for the interior structure of a planet?
a. Density
b. Rotation rate
c. Revolution rate
d. Atmospheric pressure
e. The number of moons the planet has
20. 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.
21. What is the Titius-Bode law?
a. It is a description of the spacing between the planets' orbits
b. it explains why planets have elliptical orbits
c. It explains why the outer planets move more slowly than
the inner planets
d. It proves that P2 = a3
22. The concept of the Celestial Sphere was originated by _____ .
a. the ancient Eqyptians
b. the American Indians
c. the ancient Greeks
d. the early inhabitants of Australia
e. decree of the International Astronomical Union in 1918
23. What is the role played by the irregularities
in the planetary properties in theories
of the formation of the Solar System?
a. They are minor and are ignored by astronomers.
b. They don't affect the fundamental model, but do require that theories
be flexibile enough to account for irregularities
c. Theories of the formation of the Solar System are based entirely
on having an ability to explain the irregularities.
d. The Solar System has no irregularities; it is perfect in form.
24. 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
25. Planetesimals started to form with _____ .
a. the collision and coalescence of dust particles
b. the merging of many protoplanets
c. the capture of gas from the Solar Nebula by dust particles
d. the capture of gas from the Solar Nebula by protoplanets
26. The highest high tides during a month occur when _____ .
a. the Moon is first and third quarter
b. the Moon is new
c. the Moon is full
d. the Moon is new and full
e. the Moon passes through the ecliptic plane
27. The Moon is full. At what time does the Moon appear highest in the sky?
a. noon
b. sunset
c. midnight
d. sunrise
e. it depends on the season
28. The rotation period of the Earth ______
tidal forces exerted by the Moon on the Earth.
a. is increasing in length because of the
b. is decreasing in length because of the
c. is not affected by the
d. periodically varies in length from 23h 56 min to 24 h because of the
29. The retrograde episodes of Mars, as seen from the Earth, recur ______ .
a. on the sidereal period of revolution of Mars
b. on the synodic period of Mars
c. on the sidereal period of rvolution of the Earth
d. every six months
e. every leap year
30. A large reason why the Heliocentric
theory for the Solar System was
not accepted for more than 1,700 years was _____ .
a. the anomalously large observed annual trigonometric parallax
b. that the scientific community allowed themselves
to be driven by politics, not science
c. that the ancient Greeks were considered to be primitive
and not capable of science
d. that annual trigonometric parallax was not observed!
e. that the Geocentric theory for the Solar System
matched the observations much
more closely than did the Heliocentric theory
31. Venus evolved so that its surface temperature is now 800-900 F while the
Earth has evolved so that its average surface temperature is now ~70 F. The
explanation for this is that _____ .
a. Venus was born with a massive carbon dioxide atmosphere while the Earth was not
b. Venus did not have water when it was born while the Earth had plentiful water at birth
c. liquid oceans could not form on Venus while they could on Earth
d. Earth has polar ice caps that reflect sunlight efficiently while Venus does not
e. Earth was struck by a large Mars-sized body in its early history
that boiled off the carbon dioxide
32. Of the following celestial objects, which can never be seen at
midnight by an observer in Eugene?
a. Moon
b. Venus
c. Mars
d. Jupiter
e. Saturn
33. The ecliptic is the _____ .
a. projection of the Earth's equator onto the Celestial Sphere
b. the cone the Earth's rotational axis marks on the Celestial Sphere
c. apparent path of the Moon through the stars
d. apparent path of the Sun through the stars
e. The path traced out by the slow motion of the line-of-nodes about the Sun
34. Lunar and Solar eclipses will occur _____ .
a. whenever the Moon is full
b. whenever the Moon is new
c. only when the line-of-nodes points toward the Sun
d. only when the line-of-nodes makes a right angle
to the direction to the Sun
e. whenever there is a high tide
35. On what day are the hours of darkness and daylight the same
for an observer in Eugene?
a. the summer solstice
b. the winter solstice
c. the vernal equinox
d. February 29th (that is, only during a leap year)
e. January 1
36. The period on which the seasons recur is the _____.
a. sidereal year
b. synodic month
c. tropical year
d. Saros cycle
e. diurnal cycle
37. Copernicus adopted the Heliocentric theory because _____ .
a. new data made it compelling compared to the Geocentric model
b. trigonometric parallax was discovered in 1500
c. it was aesthetically pleasing to him
d. he discovered that the Universe was much larger than previously thought
e. the laws of physics as understood in his day indicated a Heliocentric
Solar System
38. The daily paths of stars for an observer situated on the equator
of the Earth are best described as _______ .
a. circles moving parallel to the horizon
b. circles centered on the zenith of the observer
c. ellipses that make angles of 45o 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
39. The Solar day is longer
than the sidereal day because _______ .
a. of tidal forces exerted on the Earth by the Moon
b. the rotation axis of the Earth is slowly precessing
c. the Moon orbits slowly about the Earth
d. the line-of-nodes slowly precesses
e. the Earth orbits about the Sun
40. Which of the following is a FALSE statement about
the motions of the planets?
a. The planets move through the Zodiac constellations.
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.
41. 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. cannot be easily understood in a heliocentric model
42. Which of the following is not a property associated with
planetary motions?
a. All planets orbit about the Sun in the same direction.
b. All planets orbit around the Sun roughly in the ecliptic plane.
c. All planets orbit about the Sun in elliptical orbits.
d. All of the above are true statements about planetary motion.
43. The fact that the Earth travels the fastest in its orbit in January when
it is the closest to the Sun may 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
44. Based on Kepler's third law (the Harmonic Law) we may infer that ______ .
a. the Solar Day is the longest when the Earth is closest to the Sun
b. Mercury has a shorter sidereal revolution period than does Mars
c. the Sun sits at the center of all planetary orbits
d. comets must be very old
e. the asteroids are a planet that was torn apart by Jupiter during the
early evolution of the Solar System
45. Pluto falls into the ________ group of planets.
a. Terrestrial
b. Jovian
c. Uranian/Neptunian
d. Icy
e. Sun-like
46. Of the following planets, which planet's orbital characteristics differs
most from the other planets listed?
a. Venus
b. Earth
c. Uranus
d. Pluto
e. Jupiter
47. If an observer only 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 = 30o S)
e. any of the above sites.
48. The Jovian 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
49. The seasons are caused by _____ .
a. the varying distance of the Earth from the Sun
b. the tilt of the plane of the Moon's orbit in relation to the ecliptic
c. the motion of the Vernal Equinox on the sky
d. the tilt of the Earth's rotation axis to the perpendicular to the ecliptic
e. the precessional motion of the rotation axis of the Earth
50. Which of the following must theories for the formation of
the Solar System explain?
a. the orbital regularities of the planets
b. the existence of three general classes of planets
c. the origin and nature of the comets
d. the chemical composition of the Jovian planets
e. Any theory should be able to explain all of the above.