question

The planets in our solar system are thought to have come from

answer

the same cloud of gas and dust in which the Sun formed

question

What is the main reason that Earth's composition is different from Jupiter's?

answer

Compared to Jupiter, Earth formed in a hotter region, where only rocks and metals could exist as solids

question

As the solar nebula collapsed, it became a disk because

answer

the overall rotation of the nebula plus collisions between particles made the particles go in more or less the same direction

question

The jovian planets contain large abundance of hydrogen and helium because

answer

beyond the front line, the gravity of large, ice-rich planetesimals captured the abundant H and He gas

question

Because of the temperatures in the protoplanetary disk,

answer

rocks and metals froze in both the inner and outer regions, and ice froze only in the outer region

question

As the solar system nebula collapsed under its own gravity

answer

it heated and spun up

question

Suppose the solar nebula had cooled much more before the solar wind cleared away the remaining gas. In that case, the terrestrial planets likely would have ended up:

answer

with a higher abundance of hydrogen compounds and larger size

question

If the solar nebula initially had no angular momentum

answer

there would not be any planets orbiting the Sun

question

Suppose the solar nebula had been too warm for ices to condense anywhere. If a planet had still formed at Jupiter's location, it most likely would have

answer

been similar in composition to Earth, with a much smaller mass than the real Jupiter

question

Terrestrial Planets

answer

small size; solid, rocky surface; located within the inner solar system

question

Jovian Planets

answer

primarily composed of hydrogen, helium, and hydrogen compounds; extensive ring systems; numerous orbiting moons; low average density

question

Assuming that other planetary systems form in the same way as our solar system formed, where would you expect to find terrestrial planets?

answer

Terrestrial planets will likely be located nearer the planetary system's star than any Jovian planets

question

Compared to terrestrial planets, jovian planets are

answer

more massive and lower in average density

question

Which planet is approximately halfway between Pluto's orbit and the Sun?

answer

Uranus, the seventh planet from the Sun

question

In which of the following ways do Pluto and Eris differ from the terrestrial and jovian planets in our solar system?

answer

-Smaller than any of the terrestrial planets -Travel in more elliptical orbits than ay of the terrestrial or jovian planets -Less massive than any of the terrestrial or jovian planets

question

What substances were found within the inner 0.3 AU of the solar system before planets began to form?

answer

Rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form

question

What substances existed as solid flakes within the inner 0.3 AU of the solar system before planets began to form?

answer

none

question

Where would you expect terrestrial planets to form in the solar nebula?

answer

Anywhere between 0.3 AU and the frost line

question

The jovian planets are thought to have formed as gravity drew hydrogen and helium gas around planetesimals made of

answer

rocks, metals, and ices

question

Terrestrial planets

answer

-Accreted from planetesimals of rock and metal -Surfaces dramatically altered during the heavy bombardment

question

Jovin planets

answer

-Accreted from icy planetesimals -Formed in a region of the solar system with lower orbital speeds -Large moons formed in surrounding disks of material -Ejected icy planetesimals that are now Oort cloud comets

question

Our solar system was created by the gravitational collapse of the

answer

solar nebula

question

Our moon was most likely formed by a collision between Earth and a Mars sized

answer

planetesimal

question

The first few hundred million years of the solar system's history were the time of __________________ during which Earth suffered many large impacts.

answer

heavy bombardment

question

Mars was formed by the __________________ of smaller objects.

answer

accretion

question

The era of planet formation ended when the remaining hydrogen and helium gas of the solar nebula was swept into interstellar space by the

answer

solar wind

question

Ice can form from a gas through the process of

answer

condensation

question

Hydrogen compounds in the solar system can condense into ices only beyond the

answer

frost line

question

__________________________ allows us to determine the age of a rock

answer

radiometric dating

question

Which of the following three kinds of objects resides closer to the Sun on average?

answer

Asteroids

question

Planetary orbits in our solar system are

answer

fairly circular and in the same plane

question

Which have more moons on average?

answer

Jovian planets

question

All four of the giant outer planets: Jupiter, Saturn, Uranus, and Neptune- have rings. T/F

answer

True

question

All planets orbit the Sun in the same direction (counterclockwise as viewed from above Earth's North Pole) T/F

answer

True

question

All the planets in the solar system have at least one moon. T/F

answer

False

question

The more massive planets in the solar system tend to be less dense than the lower mass planets. T/F

answer

True

question

All comets orbit the Sun in the same direction as the planets. T/F

answer

False

question

Suppose that the Sun shrank in size, but its mass remained the same. What would happen to Earth's orbit?

answer

Earth's orbit would be unaffected

question

Which planet listed below has the most extreme seasons?

answer

Uranus

question

List 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

Which is NOT a characteristic of the outer planets?

answer

They have very few, if any, satellites.

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

Solar nebula:

answer

98% hydrogen and helium

question

Which lists the major steps of solar system formation in the correct order?

answer

Collapse, condensation, accretion

question

Which of the following did not occur during the collapse of the solar nebula?

answer

Concentrating denser materials nearer the Sun

question

What's the leading theory for the origin of the Moon?

answer

It formed from the material ejected from Earth in a giant impact

question

Which of the following types of material can condense into what we call ice at low temperatures?

answer

Hydrogen compounds

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 ices to condense

question

According to our present theory of solar system formation, which of the following explains why the solar system nebula ended up with a disk shape as it collapsed?

answer

It flattened as a natural consequence of collisions between particles in the nebula.

question

According to our theory of solar system formation, what are asteroids and comets?

answer

Leftover planetesimals that never accreted into planets.

question

According to modern scientific dating techniques, approximately how old is the solar system?

answer

4.5 billion years

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-sized object.

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

The planet in our solar system with the highest average surface temperature is _________________

answer

Venus

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