astronomy exam 2 Flashcards
T/F: With the exception of Venus, planetary surface temps decrease at greater. distances from the sun
True
t/f: Pluto is part of the Oort Cloud
False
t/f: within the frost line, planetesimals were composed entirely of rock, and outside the frost line, planetesimals were composed entirely of ice
false
An object orbiting a larger object that orbits the sun is called a
moon
between the orbits of mars and Jupiter lies a place called the
frost line
what do we mean by accretion in the context of planet formation
the growth of planetesimals from smaller solid particles that collided and stuck together
The frost line is between the orbits of which two planets
Mars & Jupiter
T/F: The more massive planets in the solar system tend to be less dense than the lower mass planets
True
according to our theory of solar system formation, which law best explains why the solar nebula spun faster as it shrank in size
the law of conservation of angular momentum
which of the following are relatively unchanged fragments from the early period of planet building in our solar system
Oort clouds comets, asteroids, Kuiper Belt comets
T/F: all the planets in the solar system have at least one moon
False
suppose you start with 1 kg of radioactive substance that has a half-life of 10 years. which of the following statements will be true after 20 years pass
you’ll have .25 kg of the radioactive substance remaining
suppose you view the solar system from high above earth’s North Pole. which of the following statements about planetary orbits will be true?
all the planets orbit counterclockwise around the sun
in essence, the solar nebular theory states that
our solar system formed from the collapse of an interstellar cloud of gas and dust
according to our theory of solar system formation, what are asteroids and comets?
leftover planetesimals that never accreted into planets
which of the following is not a characteristic of the inner planets
they have substantial atmosphere
in which part of the solar system is Pluto found
the Kuiper belt
T/F: Jupiter and the other gas giants formed close to the sun and migrated outward
False
where are most of the known asteroids found?
between the orbits of mars and Jupiter
based on studies of the composition of stars and interstellar gas clouds, what was the approximate chemical composition of the solar nebula
98% hydrogen
t/f: earth is the only planet in the solar system known to have active plate tectonics across its entire surface
true
which of the following most likely explains why Venus does NOT have a global magnetic field like earth
its rotation is too slow
rank the five terrestrial worlds in order of size from smallest to largest
Moon, Mercury, Mars, Venus, Earth
In what way is Venus most similar to earth
both planets are nearly the same size
The core, mantle, and crust of a planet primarily have differences in their
density
T/F: Today, Mars has no global magnetic field
true
T/f: in the inner solar system, the largest surface features are found on the largest planets
False
The planet in our solar system with the highest average surface temp is
Venus
How does earth’s magnetosphere affect our atmosphere
it deflects solar wind particles that would otherwise strip away the atmosphere
There are no auroras on Venus because it
lacks a strong magnetic field
mars has two moons that are most similar in character to
small asteroids
which planet has been visited by the largest number of robotic spacecraft
mars
T/F: with the exception of Venus, planetary surface temps decrease at greater distances from the sun
True
which of the following best describes the lunar Maria
relatively smooth, flat plans on the moon
mars’ atmosphere is mostly carbon dioxide, why does it not experience a runaway greenhouse effect like Venus
Mars’ atmosphere is too thin
True/False: earth is habitable in part due to the greenhouse effect
True
which of the following worlds has the thickest atmosphere
Venus
which planet could an astronaut visit without the need for a spacesuit, and survive
None, they need a spacesuit
which of the terrestrial worlds has the strongest magnetic field
Earth
which planet has the most extreme temps difference between day and night
Mercury
why do astronomers believe that triton is a captured moon
Triton orbits Neptune in a direction opposite that of Neptunes rotation
why do Uranus and Neptune appear blue
the methane gas in their atmospheres absorbs all colors except blue
T/F: the mass of Saturn can be determined by applying Kepler’s 3rd law to the motion of a single ice particle in its rings
True
T/F: it is impossible to land a spacecraft on any moons of the Jovian planets
False
T/F: Only one of the moons of the jovian planets has an atmosphere thicker than earth’s atmosphere
True
True/ False: Jupiter is the only Jovian planet with large storms
False
where is Jupiter’s strong magnetic field generated
metallic hydrogen layer
How do typical wind speeds in Jupiter’s atmosphere compare to typical wind speeds on earth
they are much faster than average wind speeds on earth
which statement about Io is true
it is the most volcanically active body in our solar system
which moons are sometimes called the Galilean moons
the four largest moons of Jupiter: Io, europa, Ganymede, and Callisto
T/F: Ganymede is larger than Mercury, but it is not classified as a planet because it orbits Jupiter as opposed to the sun
True
which planet has the lowest density
saturn
which jovian planet does not have rings
all jovian planets have rings
overall, Jupiters composition is most like that of
the sun
what is the great red spot
a long-lived, high-pressure storm on jupiter
what would you see as you looked down on the rings
countless ice particles, ranging in size from dust grains to large boulders
which moon has a thick atmosphere made mostly of nitrogen
Titan
which of the following is not general characteristic of the four jovian planets in our solar system
they are higher in average density than are the terrestrial planets
which jovian planet should have the most extreme seasonal changes
Uranus
