PSU ASTRO 7N CORE EXAMS 2026 SET QUESTIONS AND
ANSWERS GRADED A+
✔✔In what ways does a 5 meter telescope outperform a 1 meter telescope?
A: All objects observed by the 5 meter will appear larger.
B: Its images are 25 times brighter than a 1 meter.
C: It will produce better "seeing" than the 1 meter.
D: It can observe light with a wavelength 5 times longer than the 1 meter.
E: It will not suffer from spherical aberration like the 1 meter. - ✔✔B
✔✔A mountain top is a good location for optical telescopes because the site ...
A: has cold weather which improves the performance of the instruments
B: is closer to astronomical objects
C: has warm weather which improves the performance of the instruments
D: is above much of the atmosphere
E: has high altitude which expands the glass in the mirror and makes it smoother - ✔✔D
✔✔Which statement about the rotation of the Inner planets is true?
A: Venus rotates in the opposite direction from the three others.
B: All rotate in the same direction.
C: The rotation periods of all of them are the same — i.e., 1 Earth day.
D: All have rotation periods of 365 Earth days.
E: All have rotation periods about equal to their periods to orbit the Sun. - ✔✔A
✔✔Which of the following is TRUE?
A: The average surface temperature of Venus is about 30 degrees Fahrenheit.
B: Mercury has a very thick atmosphere made mostly of carbon dioxide.
C: The runaway greenhouse effect causes the present temperatures on Mars to exceed
those on Earth.
D: Mercury rotates exactly one and a half times for every one revolution around the
Sun.
E: Venus has no volcanoes on its surface. - ✔✔D
✔✔Why do the orbits of the planets all lie in nearly the same plane?
A: Collisions between planetesimals destroyed all planets that would have been
elsewhere.
B: The Sun's gravity forced them into these orbits.
C: The early solar nebula flattened into a disk.
D: The angular momentum of the solar system was kept to a minimum this way.
E: This happened purely by chance. - ✔✔C
✔✔Of these choices, which planet has the most moons?
A: Earth
B: Mercury
C: Saturn
, D: Mars
E: Venus - ✔✔C
✔✔Venus is visible to us ...
A: only near sunrise or sunset.
B: only during the several hours around midnight.
C: only in the winter.
D: only in the summer.
E: only during its new phase. - ✔✔A
✔✔A planet is in orbit around the Sun. The semimajor axis of the orbit is 5 Astronomical
Units (AU). Use P 2 = a 3 to calculate the period of the orbit, in years. A: 5 years
B: 0.2 years
C: 135 years
D: 125 years
E: 11.2 years - ✔✔E
✔✔In the above diagram, how should the parameters of the white curve be changed in
order that it matches the observed distance versus time graph of Callisto?
A: increase a and decrease P
B: increase P and shift the curve
C: decrease a and decrease P
D: shift the curve and increase a
E: decrease P and decrease a - ✔✔B
✔✔How do most craters on moons form?
A: by volcanic activity
B: running water
C: by seismic activity (earthquakes)
D: earthquakes
E: impact of asteroids - ✔✔E
✔✔Which planet has a temperature of 800 degrees Fahrenheit on the side facing the
Sun and -290 degrees Fahrenheit on the side opposite the Sun?
A: Mars
B: Venus
C: Earth
D: Jupiter
E: Mercury - ✔✔E
✔✔How many Earth years does it take Uranus to orbit the Sun?
A: 84
B: 1
C: 0.48
D: 2.4
ANSWERS GRADED A+
✔✔In what ways does a 5 meter telescope outperform a 1 meter telescope?
A: All objects observed by the 5 meter will appear larger.
B: Its images are 25 times brighter than a 1 meter.
C: It will produce better "seeing" than the 1 meter.
D: It can observe light with a wavelength 5 times longer than the 1 meter.
E: It will not suffer from spherical aberration like the 1 meter. - ✔✔B
✔✔A mountain top is a good location for optical telescopes because the site ...
A: has cold weather which improves the performance of the instruments
B: is closer to astronomical objects
C: has warm weather which improves the performance of the instruments
D: is above much of the atmosphere
E: has high altitude which expands the glass in the mirror and makes it smoother - ✔✔D
✔✔Which statement about the rotation of the Inner planets is true?
A: Venus rotates in the opposite direction from the three others.
B: All rotate in the same direction.
C: The rotation periods of all of them are the same — i.e., 1 Earth day.
D: All have rotation periods of 365 Earth days.
E: All have rotation periods about equal to their periods to orbit the Sun. - ✔✔A
✔✔Which of the following is TRUE?
A: The average surface temperature of Venus is about 30 degrees Fahrenheit.
B: Mercury has a very thick atmosphere made mostly of carbon dioxide.
C: The runaway greenhouse effect causes the present temperatures on Mars to exceed
those on Earth.
D: Mercury rotates exactly one and a half times for every one revolution around the
Sun.
E: Venus has no volcanoes on its surface. - ✔✔D
✔✔Why do the orbits of the planets all lie in nearly the same plane?
A: Collisions between planetesimals destroyed all planets that would have been
elsewhere.
B: The Sun's gravity forced them into these orbits.
C: The early solar nebula flattened into a disk.
D: The angular momentum of the solar system was kept to a minimum this way.
E: This happened purely by chance. - ✔✔C
✔✔Of these choices, which planet has the most moons?
A: Earth
B: Mercury
C: Saturn
, D: Mars
E: Venus - ✔✔C
✔✔Venus is visible to us ...
A: only near sunrise or sunset.
B: only during the several hours around midnight.
C: only in the winter.
D: only in the summer.
E: only during its new phase. - ✔✔A
✔✔A planet is in orbit around the Sun. The semimajor axis of the orbit is 5 Astronomical
Units (AU). Use P 2 = a 3 to calculate the period of the orbit, in years. A: 5 years
B: 0.2 years
C: 135 years
D: 125 years
E: 11.2 years - ✔✔E
✔✔In the above diagram, how should the parameters of the white curve be changed in
order that it matches the observed distance versus time graph of Callisto?
A: increase a and decrease P
B: increase P and shift the curve
C: decrease a and decrease P
D: shift the curve and increase a
E: decrease P and decrease a - ✔✔B
✔✔How do most craters on moons form?
A: by volcanic activity
B: running water
C: by seismic activity (earthquakes)
D: earthquakes
E: impact of asteroids - ✔✔E
✔✔Which planet has a temperature of 800 degrees Fahrenheit on the side facing the
Sun and -290 degrees Fahrenheit on the side opposite the Sun?
A: Mars
B: Venus
C: Earth
D: Jupiter
E: Mercury - ✔✔E
✔✔How many Earth years does it take Uranus to orbit the Sun?
A: 84
B: 1
C: 0.48
D: 2.4
