Exsu02_1
ASTRO 001.101 SUMMER 2002 EXAM 1
NAME (print): ______ID# ______
Sun’s diameter = 93,000,000 miles = 150,000,000 km
Earth’s diameter = 7900 miles = 12,800 km
I. Multiple-Choice. In each case, please chose the one best response. [2 pts each]
In the figure above, we observe the Sun from State College, PA, at three possible rising locations (1, 2 and 3) along the eastern horizon. Due east is marked with a vertical bar and labeled EAST. Please refer to this diagram when responding to Questions 1 - 3.
- Which position is closest to the rising position of the Sun on the autumnal equinox?
a)1
b)2
c)3
- Of the three rising positions, which results in the Sun reaching its highest mid-day altitude?
a)1
b)2
c)3
- Which rising Sun best depicts the Sun as it rose today (May 21, 2002)?
a)1
b)2
c)3
- Of the three arrows (labeled X, Y and Z) drawn below, which best depicts the motion of the Sun as it departs the horizon from position 3 and moves across the sky on its daily path?
a)X
b)Y
c)Z
d)The Sun actually moves downward, and to the right, so none of the arrows accurately depicts the Sun’s motion.
- Now, we turn our attention to the western horizon on the same day depicted in FIGS 1 and 2 above. Which of the Suns depicted below (i, j, k) best depicts the setting location of Sun #3 in FIGS 1 and 2?
a)i
b)j
b)k
- Finally, we move our viewing location to a point on Earth’s equator, and reproduce FIG 2 below. We’re again looking east. Now which arrow best depicts the Sun’s motion as it leaves the horizon?
a)X
b)Y
c)Z
- While facing north on a clear evening, you spot the star Zaphod at position 1 (see diagram above). Which of the remaining locations (2, 3, 4 and 5) best depicts Zaphod’s position in your sky 6 hours later? [Polaris is also known as the “north star.”]
a)2
b)3
c)4
d)5
e)Six hours later, Zaphod will have set, so will not be visible in your sky.
- The observed motion of Zaphod relative to Polaris in the course of an evening results from ______.
a)the precession of Earth’s rotational axis
b)the revolution of Earth about the Sun
c)the rotation of Earth on its axis
d)intrinsic motions of stars relative to each other – like the motion of bees in a swarm
- Were we now to depart on a quick trip to Florida, we would find that the star Polaris ______.
a)gets closer to the northern horizon
b)gets farther from the northern horizon
c)does not change its distance above the horizon, as depicted above
d)maintains its altitude above the horizon, as depicted above, but gradually drifts eastward, so that eventually it appears directly above the east point on the horion
e)By the time we get to Florida, Polaris certainly will have disappeared below the northern horizon.
- The constellations of the Zodiac were of special interest to ancient astronomers because ______.
a)they form the background of the celestial equator
b)they form the background of the ecliptic, the Sun’s path around the celestial sphere
c)they are all circumpolar as observed from Greece
d)they can be observed only from Mount Olympus
e)space aliens come from a star system located in the middle of the Zodiac
- The celestial meridian may best be described as ______.
a)the great circle on the celestial sphere dividing the sky into a north half and a south half
b)the Moon’s apparent path on the celestial sphere as it orbits Earth
c)the great half-circle connecting north and south points on your horizon, which divides the sky into east and west halves
d)the line of intersection between the orbit planes of Earth and the Moon
- One astronomical unit (AU) is equal to ______.
a)the average distance between Earth and the Sun
b)the average distance between Earth and the Moon
c)Earth’s circumference
d)1 light hour
e)the distance between Earth and the nearest star beyond the Sun
Here are some astronomical distances/sizes. Match one of these with each of the following statements.
a)10 light years
b)10 AU
c)1 million miles
d)100,000 light years
e)1 million light years
- Diameter of the galaxy we inhabit. d)
- Distance to stars nearest to the Sun. a)
- Possible distance of a planet orbiting the Sun. b)
- The Sun’s diameter. c)
- Suppose the circle above represents the galaxy we inhabit, the Milky Way. Which of the numbered locations best depicts the Sun’s position in the galaxy?
a)1
b)2
c)3
d)4
Here’s a depiction of the sky as you observe it from a locale in Earth’s northern hemisphere:
19. Of the numbered locations, which lies closest to where we might look in this sky to find the celestial equator?
a)1
b)2
c)3
d)4
20. A possible location for the noon Sun on the winter solstice would be ______.
a)1
b)2
c)3
d)4
21. Here’s a depiction of the noon Sun (the smiley). You’re looking south, of course, with a certain star lined up just above it. (Assume that we can see stars in broad daylight.) One week later, about where would we find the star, again at noon? Choose among the three stars labeled 1, 2 and 3.
a)1
b)2
c)3
d)Actually, we can’t tell. It could be 1 or it could be 2. Depends on the season of the year.
22. As observed from State College, the sun is observed to set directly west ______.
a)once per week
b)every day of the year
c)twice per year
d)once per year
e)once every 29.5 days
23. In 5000 years (in the year 7002, to be precise), the star Polaris will be just as close to the north celestial pole as it is today.
a)True
b)False
Consider an imaginary planet where the following conditions prevail:
(1)Its orbit period is 6 Earth months.
(2)Its rotation period is 12 Earth hours.
(3)This planet’s single moon orbits the planet, in the same sense that the planet rotates, with true orbit period 31 days.
(4)A ‘side’ view of the planet looks like this:
(Angle between equator and orbit plane is 41o.) Please refer to this diagram and accompanying information when responding to Questions 24 – 26.
24. What’s the latitude of this planet’s arctic circle?
a)41o
b)66.5o
c)23.5o
d)49o
e)90o
25. As observed from this planet, the interval of time between full phases of its moon is ______.
a)exactly 31 days
b)less than 31 days
c)more than 31 days
26. At 45o north latitude on this planet, the Sun appears at what altitude at noon on its winter solstice?
a)45o
b)41o
c)86o
d)21.5o
e)4o
27. Let the Sun be represented by the circle on the left.(above). Which of the circles/dots on the right best represents the Earth, on this scale?
a)1
b)2
c)3
d)4
28. We see different stars in the sky at 10:00 pm on June 1 than we see at 10:00 pm on December 1. This difference is due to ______.
a) the rotation of Earth on its axis
b) the revolution of Earth about the sun
c) precession of Earth’s rotational axis
d) motion of the stars in space
e) differences of cloud cover between June and December
29. We see the moon go through a cycle of phases because ______.
a) the half of the moon which is illuminated by the sun becomes more or less visible from Earth as the moon orbits it
c) the moon’s rotation brings more or less of its illuminated hemisphere into view from Earth
d) Earth’s shadow slowly moves over the moon as it orbits Earth
e) the variation in the moon’s distance from Earth as it orbits Earth causes its brightness to change
30. A lunar eclipse does not occur at every full moon because ______.
a) the moon’s orbit is an ellipse, not a circle
b) Earth’s rotation axis is tilted
c) The Moon’s orbit plane is inclined to Earth’s orbit plane
d) The Moon’s orbit plane is inclined to Earth’s equatorial plane
- The moon might not look completely dark when it is in Earth’s shadow during a total lunar eclipse because ______.
a)the surface of the moon is hot, thus it glows.
b)the moon’s atmosphere produces a faint glow.
c)sunlight reflected from Earth’s clouds reaches the moon.
d)sunlight passing through the moon’s atmosphere is refracted into the moon’s shadow
e)sunlight passing through Earth’s atmosphere is refracted into Earth’s shadow.
- On the largest distance scales, galaxies seem to be ______.
a)found in a few very large spherical clumps
b)uniformly distributed throughout the universe
c)found in one giant clump very close to the Milky Way galaxy
d)arranged along long filaments
- At some time during the year, the sun appears in the zenith (i.e., straight overhead) as viewed from State Collge, PA.
a)True
b)False
- Summer in the northern hemisphere occurs when ______.
a)Earth lies closest to the sun
b)Earth’s northern hemisphere is tilted away from the sun
c)Earth’s northern hemisphere is tilted toward the sun
d)Earth lies farthest from the sun
e)The speed of Earth in its orbit is smallest
- The distance between Earth and the moon is increasing (really!). This means that, over the course of time, the moon’s angular diameter, as viewed from Earth ______.
a)will increase so long as the distance continues to increase
b)will decrease so long as the distance continues to increase
c)will increase first for awhile, then decrease as the distance approaches infinity
d)will decrease first for awhile, then increase as the distance approaches infinity
e)will not change at all
- To a person standing at Earth’s north pole, the north celestial pole will appear ______.
a)on the horizon at all times
b)in the zenith at all times
c)on the ecliptic at all times
d)to change position in the sky as the seasons change
- Of the two types of total eclipses, one is much more common to see from a given location on Earth. Why?
a)It’s more likely to be cloudy for a total lunar eclipse.
b)Total eclipses of the moon occur much more frequently.
c)A total eclipse of the moon is visible from only a narrow path on Earth.
d)A total eclipse of the sun is visible from only a narrow path on Earth.
e)Total eclipses of the sun occur much more frequently.
- If you found that you were located within the penumbra of the moon’s shadow during an eclipse, you would observe the ______.
a)sun to be totally eclipsed
b)sun to be partially eclipsed
c)moon to be totally eclipsed
d)moon to be partially eclipsed
- At what average speed does the sun appear to move across our sky with respect to the stars (assuming that we could see stars during the day) in order to circle the sky once in one year?
a)About 13o per day.
b)About 24o per day, or very close to 1o per hour.
c)About 1o per day
d)The sun never appears to move with respect to the stars in the sky.
- The phase of the moon during a solar eclipse is ______.
a)new
b)full
c)first quarter
d)last (third) quarter
e)waxing crescent
II. Short Answer/Essay. Please respond to each of the following in the space provided.
a) b)
c) d)
nb
- [3 Pts] Identify any three of the constellations depicted above with its proper name. Identify a fourth constellation for 2 extra credit points.
a)Leo
b)Ursa Major
c)Cassiopeia
d) Boötes
Here’s a depiction of the Moon orbiting Earth. A few moons are numbered. The Sun is located to the left of this drawing. The view is from a point above Earth’s north pole
42. [3 pts] Shade Earth and each of the moons, showing night and day. Each is bright on the left and dark on the right.
2, 8 43. [2pts] Which of the numbered moons would show a gibbous phase, as viewed from Earth?
7 44. [2 pts] Which of the numbered moons would show last quarter phase, as viewed from Earth?
7 45. [2 pts] Which of the numbered moons rises at midnight?
4 46. [2 pts] Which of the numbered moons would be on the meridian (‘overhead’) in mid-afternoon.
6 47. [2 pts Extra Credit] Which of the numbered moons could be observed as depicted above?
48. [6 pts] As depicted here, the diameter of the Moon’s orbit is 5.0 inches. In reality, this distance is 480,000 miles. Given that the distance between Earth and Sun is 93 million (93,000,000 = 9.3 x 107) miles, show how to determine the distance to the Sun on the scale of the diagram.
You needn’t solve for X to receive full credit. However, if you do, the solution is:
X = 81 ft