ESTUDYR
AS101 FULL ASSIGNMENTS UPDATED EXAM WITH MOST
TESTED QUESTIONS AND ANSWERS | GRADED A+ |
ASSURED SUCCESS WITH DETAILED RATIONALES
1. You are standing on Earth’s equator. Which way is Polaris, the North Star?
A. 30° up, due West
B. On the northern horizon (✔ )
C. Directly overhead
D. Depends on season
Rationale: At latitude 0°, Polaris sits at 0° altitude—that is, on the horizon—due north.
2. By locating the north celestial pole (NCP) in the sky, how can you determine your latitude?
A. The altitude of the NCP equals your latitude. (✔ )
B. The altitude of the NCP is your angular distance from the North Pole.
C. The azimuth of the NCP equals your latitude.
D. The azimuth of the NCP is your angular distance from the North Pole.
Rationale: On Earth, your latitude north = angle between horizon and celestial pole.
3. Orion is visible on winter evenings in the Northern Hemisphere but not summer evenings because
of:
A. Interference from the full Moon
B. The tilt of Earth’s axis
C. Earth’s location in its orbit (✔ )
D. The precession of Earth’s axis
Rationale: Constellations shift to nighttime skies by Earth’s orbital position, not axial tilt.
4. Why do we have seasons on Earth?
A. As Earth orbits, its axis remains tilted toward Polaris, so hemispheres alternate in direct sunlight. (
✔ )
B. Earth’s tilt changes between 0°–23½° each year.
,ESTUDYR
C. Earth’s distance to the Sun varies enough to change seasons.
D. Jupiter’s gravity alters our orbit seasonally.
Rationale: Constant 23.5° tilt yields varying solar angle throughout the year.
5. Which statements are true?
A. Northern & Southern hemispheres get equal sunlight on equinoxes.
B. … get equal sunlight on solstices.
C. Northern Hemisphere receives most direct sunlight on summer solstice.
D. Both A and C are true. (✔ )
Rationale: Equinox: 12 h day everywhere; summer solstice: Northern Hemisphere most tilted toward
Sun.
6. Why is it summer in the Northern Hemisphere when it is winter in the Southern Hemisphere?
A. North is closer to the Sun.
B. North is “on top” of Earth.
C. Northern Hemisphere is tilted toward the Sun, receiving more direct sunlight. (✔ )
D. Northern Hemisphere is tilted away, receiving less direct sunlight.
Rationale: Tilt toward Sun increases solar intensity and day length in one hemisphere at a time.
7. Which statement about constellations is false?
A. Only 88 official constellations exist.
B. Some are visible from both hemispheres.
C. Some can be seen in both winter and summer.
D. Most will be unrecognizable hundreds of years from now. (✔ )
Rationale: Constellation patterns change so slowly that most remain recognizable for millennia.
8. Magnitude table: δ Dra (3.07), α Cet (2.53), Nim (8.07), α CMa (–1.46). Which appears brightest?
A. δ Dra
B. α Cet
C. Nim
D. α CMa (✔ )
,ESTUDYR
Rationale: Lower (more negative) magnitude = brighter star; –1.46 is smallest.
9. What causes the precession of Earth’s rotation axis?
A. Gravitational forces from Sun and Moon on Earth’s equatorial bulge. (✔ )
B. Gravity from Sun and Jupiter on Earth–Moon system.
C. Earth’s magnetic field.
D. Asteroid impacts.
Rationale: Torques on bulge wobble Earth’s axis over ~26,000 years.
10. Ancient Greek astronomers observed planets (“wanderers”) within a narrow sky band called:
A. The ecliptic (zodiac) band. (✔ )
B. The celestial equator.
C. The galactic plane.
D. The Milky Way.
Rationale: Planets move roughly along the Sun’s path, the ecliptic, which crosses the zodiac
constellations.
11. If Earth rotates once in 24 h, how many degrees per hour does the sky appear to turn?
A. 12°/h
B. 16°/h
C. 15°/h (✔ )
D. 8°/h
Rationale: 360°/24 h = 15° per hour relative to stars (sidereal rate).
12. An observer at latitude 40.76° N sees a star rise exactly due east. Which star could later go through
zenith?
A. One with declination = +40.76° (✔ )
B. Declination = 0°
C. Declination = –40.76°
D. Declination = +90°
Rationale: Only stars whose declination equals observer’s latitude pass overhead (zenith).
, ESTUDYR
13. Where is an observer’s nadir?
A. East point on horizon
B. North point on horizon
C. Point directly opposite the zenith (✔ )
D. Opposite the north celestial pole
Rationale: Zenith is overhead; nadir is straight down.
14. Which is one – 3 600th of a degree?
A. Precession
B. Second of arc (✔ )
C. Minute of arc
D. Angular diameter
Rationale: 1° = 60′ (arcminutes) = 3 600″ (arcseconds).
15. For an observer on Earth’s equator, the zenith is:
A. Directly overhead (✔ )
B. Near southern horizon
C. Near western horizon
D. Variable with time
Rationale: Zenith is always directly overhead, regardless of latitude.
16. If Earth’s orbital eccentricity rose from 0.017 to 0.65, seasons would become:
A. More intense (✔ )
B. Less intense
C. Unchanged
Rationale: Higher eccentricity → larger difference in solar flux between perihelion and aphelion.
17. Which coordinates lie closest to the south celestial pole?
AS101 FULL ASSIGNMENTS UPDATED EXAM WITH MOST
TESTED QUESTIONS AND ANSWERS | GRADED A+ |
ASSURED SUCCESS WITH DETAILED RATIONALES
1. You are standing on Earth’s equator. Which way is Polaris, the North Star?
A. 30° up, due West
B. On the northern horizon (✔ )
C. Directly overhead
D. Depends on season
Rationale: At latitude 0°, Polaris sits at 0° altitude—that is, on the horizon—due north.
2. By locating the north celestial pole (NCP) in the sky, how can you determine your latitude?
A. The altitude of the NCP equals your latitude. (✔ )
B. The altitude of the NCP is your angular distance from the North Pole.
C. The azimuth of the NCP equals your latitude.
D. The azimuth of the NCP is your angular distance from the North Pole.
Rationale: On Earth, your latitude north = angle between horizon and celestial pole.
3. Orion is visible on winter evenings in the Northern Hemisphere but not summer evenings because
of:
A. Interference from the full Moon
B. The tilt of Earth’s axis
C. Earth’s location in its orbit (✔ )
D. The precession of Earth’s axis
Rationale: Constellations shift to nighttime skies by Earth’s orbital position, not axial tilt.
4. Why do we have seasons on Earth?
A. As Earth orbits, its axis remains tilted toward Polaris, so hemispheres alternate in direct sunlight. (
✔ )
B. Earth’s tilt changes between 0°–23½° each year.
,ESTUDYR
C. Earth’s distance to the Sun varies enough to change seasons.
D. Jupiter’s gravity alters our orbit seasonally.
Rationale: Constant 23.5° tilt yields varying solar angle throughout the year.
5. Which statements are true?
A. Northern & Southern hemispheres get equal sunlight on equinoxes.
B. … get equal sunlight on solstices.
C. Northern Hemisphere receives most direct sunlight on summer solstice.
D. Both A and C are true. (✔ )
Rationale: Equinox: 12 h day everywhere; summer solstice: Northern Hemisphere most tilted toward
Sun.
6. Why is it summer in the Northern Hemisphere when it is winter in the Southern Hemisphere?
A. North is closer to the Sun.
B. North is “on top” of Earth.
C. Northern Hemisphere is tilted toward the Sun, receiving more direct sunlight. (✔ )
D. Northern Hemisphere is tilted away, receiving less direct sunlight.
Rationale: Tilt toward Sun increases solar intensity and day length in one hemisphere at a time.
7. Which statement about constellations is false?
A. Only 88 official constellations exist.
B. Some are visible from both hemispheres.
C. Some can be seen in both winter and summer.
D. Most will be unrecognizable hundreds of years from now. (✔ )
Rationale: Constellation patterns change so slowly that most remain recognizable for millennia.
8. Magnitude table: δ Dra (3.07), α Cet (2.53), Nim (8.07), α CMa (–1.46). Which appears brightest?
A. δ Dra
B. α Cet
C. Nim
D. α CMa (✔ )
,ESTUDYR
Rationale: Lower (more negative) magnitude = brighter star; –1.46 is smallest.
9. What causes the precession of Earth’s rotation axis?
A. Gravitational forces from Sun and Moon on Earth’s equatorial bulge. (✔ )
B. Gravity from Sun and Jupiter on Earth–Moon system.
C. Earth’s magnetic field.
D. Asteroid impacts.
Rationale: Torques on bulge wobble Earth’s axis over ~26,000 years.
10. Ancient Greek astronomers observed planets (“wanderers”) within a narrow sky band called:
A. The ecliptic (zodiac) band. (✔ )
B. The celestial equator.
C. The galactic plane.
D. The Milky Way.
Rationale: Planets move roughly along the Sun’s path, the ecliptic, which crosses the zodiac
constellations.
11. If Earth rotates once in 24 h, how many degrees per hour does the sky appear to turn?
A. 12°/h
B. 16°/h
C. 15°/h (✔ )
D. 8°/h
Rationale: 360°/24 h = 15° per hour relative to stars (sidereal rate).
12. An observer at latitude 40.76° N sees a star rise exactly due east. Which star could later go through
zenith?
A. One with declination = +40.76° (✔ )
B. Declination = 0°
C. Declination = –40.76°
D. Declination = +90°
Rationale: Only stars whose declination equals observer’s latitude pass overhead (zenith).
, ESTUDYR
13. Where is an observer’s nadir?
A. East point on horizon
B. North point on horizon
C. Point directly opposite the zenith (✔ )
D. Opposite the north celestial pole
Rationale: Zenith is overhead; nadir is straight down.
14. Which is one – 3 600th of a degree?
A. Precession
B. Second of arc (✔ )
C. Minute of arc
D. Angular diameter
Rationale: 1° = 60′ (arcminutes) = 3 600″ (arcseconds).
15. For an observer on Earth’s equator, the zenith is:
A. Directly overhead (✔ )
B. Near southern horizon
C. Near western horizon
D. Variable with time
Rationale: Zenith is always directly overhead, regardless of latitude.
16. If Earth’s orbital eccentricity rose from 0.017 to 0.65, seasons would become:
A. More intense (✔ )
B. Less intense
C. Unchanged
Rationale: Higher eccentricity → larger difference in solar flux between perihelion and aphelion.
17. Which coordinates lie closest to the south celestial pole?
