Chapter 6: Formation of the Solar System - Questions, Study

Compared to the distance between Earth and Mars, the distance between Jupiter and Saturn is _________.

much larger

According to modern science, what was the approximate chemical composition of the solar nebula?

98% hydrogen and helium, 2% everything else

What does a comet look like when it is 10 AU from the Sun?

It looks like an asteroid since it is so cold there is no outgassing of volatiles.

The jovian planets in our solar system are _________.

Jupiter, Saturn, Uranus, and Neptune.

How did the lunar maria form?

Large impacts fractured the Moon's lithosphere, allowing lava to fill the impact basins.

What is the evidence for volcanism on Mars?

Lava plains, volcanos

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

Leftover planetesimals that never accreted into planets

Why isn't liquid water stable on the surface of Mars today?

Low atmospheric pressure causes water to evaporate instantly.

Which of the following lists the planets of our solar system in the correct order from closest to farthest from the Sun?

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

The terrestrial planets in our solar system are _________.

Mercury, Venus, Earth, and Mars.

What is the liquid in Titan's rivers and lakes?

Methane

Which of the following is not a major pattern of motion in the solar system?

Nearly all comets orbit the Sun in same direction and roughly the same plane.

How did gravitational collapse affect the Solar nebula?

Nebulae are made of dust and gases—mostly hydrogen and helium. ... Eventually, the clump of dust and gas gets so big that it collapses from its own gravity. The collapse causes the material at the center of the cloud to heat up-and this hot core is the beginning of a star.

Does Venus have Plate Tectonics?

No, Venus is a single plate planet, probably because it lacks water.

What is the origin of the Oort cloud?

Objects ejected from the solar system planetary zone during planet formation and planet migration.

What answer is not something discovered in our investigations of extra-solar planets?

Only systems with asteroid belts have Earth-like planets.

90377 Sedna has an orbital period 11,400 years. This makes it part of the ___________.

The Kuiper belt.

What is the giant impact hypothesis for the origin of the Moon?

The Moon formed from material blasted out of the Earth's mantle and crust by the impact of a Mars-size object.

According to our present theory of solar system formation, how did Earth end up with enough water to make oceans?

The water was brought to the forming Earth by planetesimals that accreted beyond the orbit of Mars.

What is the Frost Line?

The zone in the Solar System far enough from the Sun where it is cold enough for ice to be stable.

Which planet listed below has the most extreme seasons?

Uranus

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

Venus

Which is answer NOT a major feature of our solar system that provides clues to its formation?

Venus has a large moon.

Why is Venus so hot?

Venus is close to the Sun and has an atmosphere with 90 bars of CO2

What is the greenhouse effect?

the trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.

What causes deserts?

rainshadow effect; 30 degrees effect

What are monsoons?

seasonal winds

What are chondrules?

solidified droplets of molten early solar system material small, glassy spherical pebbles contained in most meteorites

Does Pluto have active geology?

Yes, the NASA New Horizons mission saw mountains and glaciers caused by ice tectonics.

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?

You'll have 0.25 kilogram of the radioactive substance remaining.

How old is the solar system?

4.6 billion years old

Suppose you find a rock that contains 10 micrograms of radioactive potassium-40, which has a half-life of 1.25 billion years. By measuring the amount of its decay product (argon-40) present in the rock, you conclude that there must have been 80 micrograms of potassium-40 when the rock solidified. How old is the rock?

3.75 billion years

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

4.5 billion years

What is a hot Jupiter?

A Jupiter-sized exo-planet in an orbit very close to its parent sun.

What is a Nebula?

A cold, slowly rotating cloud of gas and dust

Why does Venus rotate slowly in a clockwise (retrograde) direction?

A giant impact probably canceled out the counter-clockwise rotation and started it spinning clockwise.

What was the solar nebula?

A large cloud of gas and dust such as the one that formed our solar system

What is the difference between a meteor and a meteorite?

A meteor is an object and burning through the atmosphere, a meteorite is on the ground.

What causes the "wobble" seen by Doppler spectroscopy?

A solar system's planets and the Sun actually orbit around a common center of mass, so the Sun actually wobbles around that common center.

What is the Kepler mission?

A spacecraft dedicated to finding earth-sized planets in the habitable zone around nearby stars. Specifically designed to survey our region of the Milky Way galaxy to discover any planets, especially Earth-size and smaller planets, in or near the habitable zone and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets

Planetary Migration

A young planet's motion can create waves in a planet-forming disk. Models show that matter in these waves can tug on a planet, causing its orbit to migrate inward.

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.

According to our basic scenario of solar system formation, why do the jovian planets have numerous large moons?

As the growing jovian planets captured gas from the solar nebula, the gas formed swirling disks around them, and moons formed from condensation accretion within these disks.

What is the origin of asteroids and comets?

Asteroids and comets—and the meteors that sometimes come from them—are leftovers from the formation of our solar system 4.6 billion years ago. While the planets and moons have changed over the millennia, many of these small chunks of ice, rock and metal have not.

A planetary magnetic field can protect the _______ from erosion by the solar wind.

Atmosphere

How old is the solar system? How do we know?

Based on radiometic dating of Earth rock, Moon rock and meteorites the solar system formed 4.56 billion years ago.

In what way is Venus most similar to Earth?

Both planets are nearly the same size.

How does doppler spectroscopy detect an exo-planet?

By observing the periodic velocity shift of the stellar spectrum caused by an orbiting planet that forces the Sun and the planet to orbit a common center.

Name two greenhouse gases.

CO2 and methane

Jupiter has large numbers of small, irregular moons with distant, random orbits. These objects are probably __________.

Captured asteroids

Besides Pluto name two dwarf planets.

Ceres, Vesta.

What are the two kinds of tails a comet has?

Dust tail, plasma tail.

What do you do in a Tsunami?

Evacuate vertically, find a solid, multistory building and go up.

What is a Kirkwood gap?

Gaps in the orbital distribution of asteroids formed by orbital resonance with Jupiter.

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

Hydrogen compounds

Jupiter and Saturn are composed of mostly of ________ and _________.

Hydrogen, helium

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

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

According to our theory of solar system formation, what three major changes occurred in the solar nebula as it shrank in size?

It got hotter, its rate of rotation increased, and it flattened into a disk.

What do we mean by the frost line when we discuss the formation of planets in the solar nebula?

It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ices to condense.

How do scientists determine the age of the solar system?

Radiometric dating of meteorites

Comets have been called dirty ____.

Snowballs

As a nebula collapses into a proto-solar disk, the disk ______ and heats up from conservation of energy and conservation of angular momentum.

Spins faster

Do other solar systems have asteroid belts and Oort clouds?

Sure, the systems would undergo the same accretional and dispersive processes.

What are two of the Earth's unique features that are important for human life?

Surface liquid water and plate tectonics.

Which of the following is not a major difference between the terrestrial and jovian planets in our solar system?

Terrestrial planets contain large quantities of ice and jovian planets do not.

Why is the Earth geologically active?

The Earth is large enough to still retain heat significant heat.

Why is the Earth geologically active?

The Earth is still releasing heat that drives continental drift and volcanism.

Which of the following is not evidence supporting the idea that our Moon formed as a result of a giant impact?

The Pacific Ocean appears to be a large crater - probably the one made by the giant impact.

Which of the following statements about our Sun is not true?

The Sun's diameter is about 5 times that of Earth.

Why is there an asteroid belt?

The asteroid belt is leftovers from accretion. Jupiter prevented a planet from forming in this zone.

How was the moon created?

The debris of a planetary crash

The following statements are all true. Which one counts as an "exception to the rule" in being unusual for our solar system?

The diameter of Earth's Moon is about 1/4 that of Earth.

What do we mean by the period of heavy bombardment in the context of the history of our solar system?

The first few hundred million years after the planets formed, which is when most impact craters were formed

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

Why are the Galilean moons geologically active?

The inner moons are heated from tidal stresses.

According to our present theory of solar system formation, which of the following statements about the growth of terrestrial and jovian planets is not true?

The jovian planets began from planetesimals made only of ice, while the terrestrial planets began from planetesimals made only of rock and metal.

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

According to our theory of solar system formation, which law best explains why the central regions of the solar nebula got hotter as the nebula shrank in size?

The law of conservation of energy

Many meteorites appear to have formed very early in the solar system's history. How do these meteorites support our theory about how the terrestrial planets formed?

The meteorites appearance and composition is just what we'd expect if metal and rock condensed and accreted as our theory suggests.

What is transit photometry?

The periodic dimming of the star caused by a planet passing in front of the star along the line of sight from the observer.

How do you detect life on an exo-planet?

The presence of oxygen in the atmosphere

What is the frostline?

The temperature was greatest in the core near the forming star and dropped with distance outwards in the disk. There was a critical distance called the FROST LINE. Inside the frost line: too hot for hydrogen compounds to form ices. Only rocks and metals condense. Outside the frost line: cold enough for ices to form; ice is important.

What is the primary basis upon which we divide the ingredients of the solar nebula into four categories (hydrogen/helium; hydrogen compound; rock; metal)?

The temperatures at which various materials will condense from gaseous form to solid form.

Why are terrestrial planets denser than jovian planets?

The terrestrial planets formed in the inner solar nebula, where only dense materials could condense.

About 2% of our solar nebula consisted of elements besides hydrogen and helium. However, the very first generation of star systems in the universe probably consisted only of hydrogen and helium. Which of the following statements is most likely to have been true about these first-generation star systems?

There were no comets or asteroids in these first-generation star systems.

Why are there asteroids and comets?

These small objects are leftovers from planetary accretion

The terrestrial planets are made almost entirely of elements heavier than hydrogen and helium. According to modern science, where did these elements come from?

They were produced by stars that lived and died before our solar system was born.

What is the phase of the moon?

Waning gibbous

Which of the following statements about Mars is not true?

We could survive on Mars without spacesuits, as long as we brought oxygen in scuba tanks.

What is the Great Red Spot?

a long-lived, high-pressure storm on Jupiter

When we say that jovian planets contain significant amounts of hydrogen compounds, we mean all the following chemicals except _________.

carbon dioxide

Why is Venus so hot?

greenhouse effect

According to our present theory of solar system formation, which of the following lists the major ingredients of the solar nebula in order from the most abundant to the least abundant?

hydrogen and helium gas; hydrogen compounds; rock; metal

In essence, the nebular theory holds that _________.

our solar system formed from the collapse of an interstellar cloud of gas and dust

How is Einstein's famous equation, E=mc2, important in understanding the Sun?

the Sun generates energy to shine by losing 4 million tons of mass each second