Chapter 6 – Space Flashcard
Unlock all answers in this set
Unlock answersquestion
Which of the following lists the planets of our solar system in the correct order from closest to farthest from the Sun?
answer
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
question
How does the Sun's mass compare with that of the planets?
answer
It is a thousand times more massive than all the planets combined.
question
What's unusual about our Moon?
answer
It's surprisingly large relative to the planet it orbits.
question
The planet closest in size to Earth is
answer
Venus
question
Which planet has the highest average surface temperature, and why?
answer
Venus, because of its dense carbon dioxide atmosphere
question
According to modern science, what was the approximate chemical composition of the solar nebula?
answer
98% hydrogen and helium, 2% everything else
question
What are the main constituents of the jovian planets?
answer
hydrogen and helium
question
Where did the elements heavier than hydrogen and helium come from?
answer
They were produced inside stars.
question
Which planet, other than Earth, has visible water ice on it?
answer
Mars
question
Suppose you view the solar system from high above Earth's North Pole. Which of the following statements about planetary orbits will be true?
answer
All the planets orbit counterclockwise around the Sun.
question
Planetary orbits in our solar system are:
answer
fairly circular and in the same plane.
question
What do we mean by accretion in the context of planet formation?
answer
the growth of planetesimals from smaller solid particles that collided and stuck together
question
The jovian planets in our solar system are _________.
answer
Jupiter, Saturn, Uranus, and Neptune
question
In essence, the nebular theory holds that _________.
answer
our solar system formed from the collapse of an interstellar cloud of gas and dust
question
Which of the following did not occur during the collapse of the solar nebula?
answer
concentrating denser materials nearer the Sun
question
Which lists the major steps of solar system formation in the correct order?
answer
collapse, condensation, accretion
question
Leftover ice-rich planetesimals are called
answer
Comets
question
The terrestrial planets are made almost entirely of elements heavier than hydrogen and helium. According to modern science, where did these elements come from?
answer
They were produced by stars that lived and died before our solar system was born.
question
According to our theory of solar system formation, what three major changes occurred in the solar nebula as it shrank in size?
answer
It got hotter, its rate of rotation increased, and it flattened into a disk.
question
Which of the following types of material can condense into what we call ice at low temperatures?
answer
hydrogen compounds
question
According to modern scientific dating techniques, approximately how old is the solar system?
answer
4.5 billion years
question
According to our theory of solar system formation, what are asteroids and comets?
answer
leftover planetesimals that never accreted into planets
question
What do we mean by the frost line when we discuss the formation of planets in the solar nebula?
answer
It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ice to condense.
question
What is the giant impact hypothesis for the origin of the Moon?
answer
The Moon formed from material blasted out of Earth's mantle and crust by the impact of a Mars-size object.
question
Why are terrestrial planets denser than jovian planets?
answer
Only dense materials could condense in the inner solar nebula.
question
Where are most of the known asteroids found?
answer
between the orbits of Mars and Jupiter
question
Which of the following statements about the accelerations and gravitational forces between a planet and a star is true?
answer
Forces are equal and opposite; the planet is accelerated more than the star.
question
According to our theory of solar system formation, which law best explains why the solar nebula spun faster as it shrank in size?
answer
the law of conservation of angular momentum
question
Based on our current theory of Earth's formation, the water we drink comes from
answer
comets that impacted Earth.
question
Which of the following is furthest from the Sun?
answer
a comet in the Oort cloud
question
According to our present theory of solar system formation, why were solid planetesimals able to grow larger in the outer solar system than in the inner solar system?
answer
because only metal and rock could condense in the inner solar system, while ice also condensed in the outer solar system
question
What is the giant impact hypothesis for the origin of the Moon?
answer
The Moon formed from material blasted out of the Earth's mantle and crust by the impact of a Mars-size object.
question
Which of the following is not a major pattern of motion in the solar system?
answer
Nearly all comets orbit the Sun in same direction and roughly the same plane.
question
Which of the following is not a characteristic of the inner planets?
answer
They all have substantial atmospheres.
question
Which of the following is the origin of almost all the large moons around the jovian planets?
answer
They were formed by condensation and accretion in a disk of gas around the planet.
question
If the freezing point of ices of all types were at a much lower temperature, what change would that imply for the formation of our solar system?
answer
The gas giants would have to form at a larger distance.
question
Which of the following statements about the recently-discovered object Eris is not true?
answer
It is thought to be the first example of a new class of object.
question
The following statements are all true. Which one counts as an "exception to the rule" in being unusual for our solar system?
answer
The diameter of Earth's Moon is about 1/4 that of Earth.
question
Which of the following observations indicates that conditions on Mars may have been suitable for life in the past?
answer
There are dried-up riverbeds on Mars.
question
Astronomers now classify Pluto as really just a large member of
answer
the Kuiper belt.
question
Which moons are sometimes called the Galilean moons?
answer
the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto
question
Which of the following statements best explains why the planets orbit in nearly a single plane and in the same direction around the Sun?
answer
The planets formed from a disk of rotating gas.
question
The region of our solar system between Mercury and Mars has very few asteroids, while the region between Mars and Jupiter has many asteroids. Based on what you have learned, what is the most likely explanation for the lack of asteroids between Mercury and Mars?
answer
There were very few planetary leftovers in this region because most of the solid material was accreted by the terrestrial planets as the planets formed.
question
What do we mean by the period of heavy bombardment in the context of the history of our solar system?
answer
the first few hundred million years after the planets formed, which is when most impact craters were formed
question
Which planet listed below has the most extreme seasons?
answer
Uranus
question
Which of the following are relatively unchanged fragments from the early period of planet building in the solar system?
answer
All of the above
question
Which of the following discoveries would cause us to re-evaluate the nebular theory for forming planets?
answer
A star's 5 terrestrial planets orbit in the opposite direction of its 3 jovian planets.
question
Suppose you start with 1 kilogram of a radioactive substance that has a half-life of 10 years. Which of the following statements will be true after 20 years pass?
answer
You'll have 0.25 kilogram of the radioactive substance remaining.
question
A rock sample from the moon includes a mineral that contains small amounts of the radioactive isotope Potassium-40 and its daughter element Argon-40 (half-life of 1.3 billion years). This mineral would not form with any Argon-40. Consider a crystal with 7 atoms of Argon-40 for every 1 atom of Potassium-40. How many half-lives has this sample existed?
answer
3
question
Suppose you find a rock that contains some potassium-40 (half-life of 1.3 billion years). You measure the amount and determine that there are 5 grams of potassium-40 in the rock. By measuring the amount of its decay product (argon-40) present in the rock, you realize that there must have been 40 grams of potassium-40 when the rock solidified. How old is the rock?
answer
3.9 billion
