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ASTRONOMY 207 MIDTERM 4 ~
UOFC ACTUAL QUESTIONS 2026
WITH VERIFIED ANSWERS.
According to the nebular theory, how did the Kuiper belt form?
a) It is material left over from the interstellar cloud that never
contracted with the rest of the gases to form the solar nebula.
b) It consists of objects that fragmented from the Sun during a
catastrophic collision early in the formation of the solar system.
c) It is made of planetesimals between the orbits of Mars and
Jupiter that never formed into a planet.
d) It is made of planetesimals formed in the outer solar system
that were flung into distant orbits by encounters with the jovian
planets.
e) It is made of planetesimals that formed beyond Neptune's
orbit and never accreted to form a planet. - correct answer-e) It
is made of planetesimals that formed beyond Neptune's orbit
and never accreted to form a planet.
According to the nebular theory, how did the Oort cloud form?
a) It is material left over from the interstellar cloud that never
contracted with the rest of the gases to form the solar nebula.
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b) It is made of planetesimals that formed beyond Neptune's
orbit and never accreted to form a planet.
c) It consists of objects that fragmented from the Sun during a
catastrophic collision early in the formation of the solar system.
d) It is made of planetesimals between the orbits of Mars and
Jupiter that never formed into a planet.
e) It is made of planetesimals formed in the outer solar system
that were flung into distant orbits by encounters with the jovian
planets. - correct answer-e) It is made of planetesimals formed
in the outer solar system that were flung into distant orbits by
encounters with the jovian planets.
Which of the following was the first strong evidence for an
asteroid impact being the cause of the extinction of the
dinosaurs 65 million years ago (as well as 75% of all species
alive at the time)?
a) the discovery of asteroid fragments in dinosaur bones dating
to that time
b) the fact that dinosaurs appear to have gone abruptly extinct
at about that time
c) careful studies of lunar craters suggesting an unusually large
number of impact at that time
d) a worldwide layer rich in the element iridium that dates to
that time - correct answer-d) a worldwide layer rich in the
element iridium that dates to that time
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What do we mean by a primitive meteorite?
a) :a meteorite that was discovered by primitive people
b) a type of meteorite that is made mostly of high-density
metals
c) a meteorite that fell to Earth at least 4 billion years ago
d) a meteorite that is essentially unchanged since it first
condensed and accreted in the solar nebula almost 4.6 billion
years ago - correct answer-d) a meteorite that is essentially
unchanged since it first condensed and accreted in the solar
nebula almost 4.6 billion years ago
What is the main factor that makes Earth more geologically
active than the other terrestrial planets?
a) It is farthest from the Sun, so it receives less light.
b) It has a large Moon, so it is heated by tidal forces.
c) It has far more radioactive material than other planets.
d) It formed much later than the other planets.
e) It is larger, so it has retained its internal heat for longer. -
correct answer-e) It is larger, so it has retained its internal heat
for longer.
ASTRONOMY 207 MIDTERM 4 ~
UOFC ACTUAL QUESTIONS 2026
WITH VERIFIED ANSWERS.
According to the nebular theory, how did the Kuiper belt form?
a) It is material left over from the interstellar cloud that never
contracted with the rest of the gases to form the solar nebula.
b) It consists of objects that fragmented from the Sun during a
catastrophic collision early in the formation of the solar system.
c) It is made of planetesimals between the orbits of Mars and
Jupiter that never formed into a planet.
d) It is made of planetesimals formed in the outer solar system
that were flung into distant orbits by encounters with the jovian
planets.
e) It is made of planetesimals that formed beyond Neptune's
orbit and never accreted to form a planet. - correct answer-e) It
is made of planetesimals that formed beyond Neptune's orbit
and never accreted to form a planet.
According to the nebular theory, how did the Oort cloud form?
a) It is material left over from the interstellar cloud that never
contracted with the rest of the gases to form the solar nebula.
, Page | 2
b) It is made of planetesimals that formed beyond Neptune's
orbit and never accreted to form a planet.
c) It consists of objects that fragmented from the Sun during a
catastrophic collision early in the formation of the solar system.
d) It is made of planetesimals between the orbits of Mars and
Jupiter that never formed into a planet.
e) It is made of planetesimals formed in the outer solar system
that were flung into distant orbits by encounters with the jovian
planets. - correct answer-e) It is made of planetesimals formed
in the outer solar system that were flung into distant orbits by
encounters with the jovian planets.
Which of the following was the first strong evidence for an
asteroid impact being the cause of the extinction of the
dinosaurs 65 million years ago (as well as 75% of all species
alive at the time)?
a) the discovery of asteroid fragments in dinosaur bones dating
to that time
b) the fact that dinosaurs appear to have gone abruptly extinct
at about that time
c) careful studies of lunar craters suggesting an unusually large
number of impact at that time
d) a worldwide layer rich in the element iridium that dates to
that time - correct answer-d) a worldwide layer rich in the
element iridium that dates to that time
, Page | 3
What do we mean by a primitive meteorite?
a) :a meteorite that was discovered by primitive people
b) a type of meteorite that is made mostly of high-density
metals
c) a meteorite that fell to Earth at least 4 billion years ago
d) a meteorite that is essentially unchanged since it first
condensed and accreted in the solar nebula almost 4.6 billion
years ago - correct answer-d) a meteorite that is essentially
unchanged since it first condensed and accreted in the solar
nebula almost 4.6 billion years ago
What is the main factor that makes Earth more geologically
active than the other terrestrial planets?
a) It is farthest from the Sun, so it receives less light.
b) It has a large Moon, so it is heated by tidal forces.
c) It has far more radioactive material than other planets.
d) It formed much later than the other planets.
e) It is larger, so it has retained its internal heat for longer. -
correct answer-e) It is larger, so it has retained its internal heat
for longer.
