quiz

According to the _____, our solar system formed from a giant cloud of interstellar gas.

nebular theory

A _____ is the time for half the nuclei in a substance to decay.

half-life

What age would radiometric dating give for a chunk of recently solidified lava from Kilauea, an active volcano in Hawaii?
a) Near zero
b) The half life of potassium-40 (1.25 billion years)
c) The half-life of uranium-238 (4.5 billion years)
d) The age of the solar system
e) The age of the volcano

Near zero

Potassium-40 has a half-life of 1.25 billion years. If you measure a rock and find that it had 100 grams of potassium-40 when it was newly-formed and now has 25 grams, how old is the rock?
A. 0 years
B. 1.25 billion years
C. 2.5 billion years
D. 3.75 billion years
E. 25 grams

2.5 billion years

Rock, metals, and ices condensed _____ the frost line, but only rock and metals condensed _____ the frost line.

outside, inside

Rock, metals, and ices condensed _____ the frost line.

outside

Rock and metals condensed _____ the frost line.

inside

Where did asteroids and comets come from?

According to the nebular theory, they are leftover planetesimals.

When did the planets form?

Radiometric dating indicates that planets formed 4.5 billion years ago.

Craters
Smooth plains
Cliffs

Mercury

Volcanoes
Few craters
Dense CO2 atmosphere

Venus

Some craters
Volcanoes
Riverbeds?

Mars

Craters
Smooth plains

Moon

Volcanoes
Craters
Mountains
Riverbeds

Earth

We say that _____ is geologically active, meaning that its surface is continually being reshaped by volcanic eruptions, earthquakes, erosion, and other geological processes.

Earth

True or False: Earth Is Not Full of Molten Lava.

True

The highest-density material, consisting primarily of metals such as nickel and iron.

Core

Rocky material of moderate density—mostly minerals that contain silicon, oxygen, and other elements.

Mantle

The lowest-density rock, which includes the familiar rocks of Earth’s surface.

Crust

What is necessary for differentiation to occur in a planet?
A. It must have metal and rock in it.
B. It must be a mix of materials of different density.
C. Material inside must be able to flow.
D. All of the above
E. B and C

B and C

True or False: The Earth Is Full of Lava.

False. The outer core is the only part of the Earth that is fully molten.

Similar to a rock, what happens to Silly Putty if you pull it VERY SLOWLY?
A. It stretches.
B. It breaks.
C. Nothing.

It stretches.

Similar to a rock, what happens to Silly Putty if you pull it SHARPLY?
A. It stretches.
B. It breaks.
C. Nothing.

It breaks.

Do rocks s-t-r-e-t-c-h?
A. No - rock is rigid and cannot deform
without breaking.
B. Yes - but only if it is molten rock.
C. Yes - rock under strain may slowly
deform.

Yes - rock under strain may slowly deform.

_____ is Earth’s most important heat source today.

Radioactive decay

Hot rock rises, cool rock falls

Convection

One convection cycle takes _____ on Earth.

100 million years

Gravity pulls _____ material to the center.
_____ material rises to surface.

This process is known as _____.

high-density, Low-density, differentiation

_____ transports heat as hot material rises and cool material falls.

Convection

_____ transfers heat from hot material to cool material.

Conduction

_____ sends energy into space.

Radiation

What cools off faster?
A. A big terrestrial planet
B. A tiny terrestrial planet

A tiny terrestrial planet

Why are smaller terrestrial bodies such as Mercury or the Moon “geologically dead”?
A. They don't have volcanoes
B. They cooled off faster than Earth did
C. They don't have erosion
D. They were hit by fewer meteorites
E. They are made of different materials than
Earth

They cooled off faster than Earth did

As a planet cools, what happens to its lithosphere?
A. Nothing, except getting colder, too.
B. It gets thicker.
C. It gets thinner.
D. It rises to the surface of the planet.
E. It sinks to the center of the planet.

It gets thicker.

If 2 planets have have the same age, a
SMALLER, cooler planet will have a
_____ lithosphere.

thicker

Moving charged particles create _____.

magnetic fields

A planet’s interior can create magnetic fields if its core is electrically _____, _____, _____.

conducting, convecting, and rotating

• Conduct electricity
• Can convect / flow (not solid)
• Rotating relatively quickly

Dynamo Effect requirements

If the planet core is cold, do you expect it to have magnetic fields?
A. Yes. Refrigerator magnets are cold, and they
have magnetic fields.
B. No. Planetary magnetic fields are generated
by moving charges around, and if the core is
cold, nothing is moving.

No. Planetary magnetic fields are generated by moving charges around, and if the core is cold, nothing is moving.

Of the terrestrial worlds, only _____ has a strong magnetic field.
– _____ rotates too slowly.
– _____, _____, _____ don’t have
enough internal heat to have a liquid metal
layer in their cores.

Earth, Venus, Mercury, Mars, and the Moon

_____ waves push
matter back
and forth.
_____ waves
shake matter
side to side.

P, S

_____ waves go through Earth’s core, but _____ waves do not.

P, S

We conclude that Earth’s core must have a _____ outer layer.

liquid

Geological Processes

Impact cratering, Volcanism, Tectonics, Erosion

Impacts by asteroids or comets

a. Impact cratering

b. Volcanism

c. Tectonics

d. Erosion

Impact cratering

Eruption of molten rock onto surface

a. Impact cratering

b. Volcanism

c. Tectonics

d. Erosion

Volcanism

Disruption of a planet’s surface by internal stresses

a. Impact cratering

b. Volcanism

c. Tectonics

d. Erosion

Tectonics

Surface changes made by wind, water, or ice

a. Impact cratering

b. Volcanism

c. Tectonics

d. Erosion

Erosion

_____ happens when molten rock (magma) finds a path through lithosphere to the surface.

Volcanism

Molten rock is called _____ after it reaches the surface.

lava

_____ of the mantle creates stresses in the crust called tectonic forces.

Convection

_____ forces make mountain ranges.

Compression

A valley can form where the crust is _____.

pulled apart

Earth’s continents slide around on _____ plates of crust.

separate

What role does a planet’s size play in its geological activity?
A. Larger planets are more geologically active because
they take longer to cool off.
B. Larger planets are more geologically active because
they have thicker lithospheres.
C. Larger planets are less geologically active because they
have thicker lithospheres.
D. Larger planets are less geologically active because they
have larger surface areas to radiate heat away.
E. Larger planets are less geologically active because there
is a greater distance between the core and the surface.

Larger planets are more geologically active because they take longer to cool off.

All X-ray light is absorbed very _____ in the atmosphere.

high

Ultraviolet light is absorbed by _____ (O3).

ozone

True or False: Earth’s atmosphere absorbs light at most wavelengths.

True

Certain molecules let sunlight through but trap escaping infrared photons.

Greenhouse effect

Any gas that absorbs infrared.

Greenhouse gas

molecules with two or more different types of elements and/or three or more atoms (H2O, CO2, CH4, O3)

Greenhouse gas

molecules with two atoms of the same element (N2, O2) or single atoms (Ar)

Not a greenhouse gas

Because of the _____, Earth is much _____ than it would be without an atmosphere (too cold for much liquid water)...but so is Venus.

greenhouse effect, warmer

Which of the following is not a greenhouse gas?
A. water vapor (H2O)
B. carbon dioxide (CO2)
C. nitrogen (N2)
D. methane (CH4)

nitrogen (N2)

Why is the sky blue?
A. The sky reflects light from the oceans.
B. Oxygen atoms are blue.
C. Nitrogen atoms are blue.
D. Air molecules scatter blue light more than red
light.
E. Air molecules absorb red light.

Air molecules scatter blue light more than red light.

The sky is blue because the atmosphere scatters _____ light from the Sun, making it appear to come from different directions.

blue

Sunsets are red because less of the _____ light from the Sun is scattered.

red

How does Earth’s atmosphere affect the planet?

Erosion, Protection from Radiation, Greenhouse effect

Was there ever geological activity on the Moon or Mercury?

Yes

Which kind of surface is probably older in our Solar System?
A. One with lots of impact craters.
B. One with very few impact craters.
C. Craters tell us nothing about a surface’s
age.

One with lots of impact craters.

When a surface is re-processed by volcanism, erosion, etc. the old craters are _____ so only new ones are present. An old surface that hasn’t been re-processed has _____ old and new craters.

erased, many

The _____ had some volcanic activity about 3 billion years ago that must have flooded lunar craters, creating _____.

moon, lunar maria

The Moon is now geologically _____.

dead

The smooth regions on Mercury are likely ancient _____.

lava flows

The _____ is the largest impact crater on Mercury.

Caloris Basin

If they are the same age, which probably has the thickest lithosphere?
A. A small terrestrial world
B. A large terrestrial world

A small terrestrial world

_____ on Mercury created long cliffs which indicate that Mercury shrank
early in its history.

Tectonics

Was there ever geological activity on the Moon?

Yes. Lunar maria resulted from early volcanism on the moon.

Was there ever geological activity on Mercury?

Yes. Tectonic features on Mercury indicate early shrinkage.

Mars versus Earth
• _____% Earth’s radius, _____% Earth’s mass
• _____ is 1.5 AU from the Sun. _____ is 1 AU from the Sun.
• Mars axis tilt is _____ _____ _____ as Earth
• _____ rotation period
• _____ has a _____ CO2 atmosphere and very little greenhouse. _____ has a _____ atmosphere and _____ of greenhouses.
• Main difference: _____ is SMALLER

50, 10, Mars, Earth, about the same, similar, Mars, thin, little, Earth, thick, lots, Mars

Seasons on Mars are more extreme in the _____ hemisphere because of its elliptical orbit.

southern

What geological features tell us that water once flowed on Mars?

The surface of Mars appears to have ancient riverbeds.

2004 _____ rover provided strong evidence for abundant liquid water on _____ in the distant past. The discovery of the mineral _____ is associated with this discovery.

Opportunity, Mars, hematite

On _____, the mineral _____ typically formed in a salty water environment.

Mars, hematite

Clumps of rounded pebbles discovered by the _____ rover compared with similar formations in Earth streambeds. Curiosity also found _____ rocks which is a characteristic of _____ by _____.

Curiosity, layered, sedimentation, water

On _____, most water lies frozen underground. Some scientists believe accumulated snowpack melts carve gullies even today.

Mars

On _____, most water lies _____ _____. The _____ _____ _____ has seen exposed water ice on _____ cliff faces.

Mars, frozen underground, Mars Reconnaissance Orbiter, Martian

Climate Change on Mars
• Mars _____ _____ had widespread surface water for _____ _____ years.
• The greenhouse effect probably kept the surface _____ before that.
• Somehow Mars _____ most of its atmosphere.
• The _____ _____ may have preserved the early Martian atmosphere.
• _____ _____ may have stripped the atmosphere after the magnetic field decreased because of interior _____.

has not, 3 billion, warmer, lost, magnetic field, Solar wind, cooling

Which of the following geological processes is currently active on
Mars?

A. volcanism
B. impact cratering
C. tectonics
D. all of the above
E. none of the above

impact cratering

Where’d Mars’ water go?
• Some are still there, _____ _____ _____ _____
• Some stripped by the _____ _____ (weak magnetic field)
• Some broken into H, O by UV light:
– H is _____, and easily escaped
– O: some lost to _____ _____, the rest “_____” Mars’ surface, so it looks _____.

frozen under the surface, solar wind, light, solar wind, rusted, red

Why are smaller terrestrial bodies such as Mercury or the Moon "geologically dead"?
A. They don't have volcanoes
B. They cooled off faster than Earth did
C. They don't have erosion
D. They were hit by fewer meteorites
E. They are made of different materials than Earth

They cooled off faster than Earth did

Somehow Mars lost most of its atmosphere, perhaps because of a _____ magnetic field.

declining

_____ has Impact craters, but fewer than Moon, Mercury, and Mars.

Venus

There are _____ volcanoes on _____.

many, Venus

_____ fractured and contorted surface indicates tectonic stresses yet, _____ does not appear to have plate tectonics, but its entire surface seems to have been “repaved” 750 million years ago.

Venus’, Venus

Photos of rocks taken by lander show _____ erosion on _____: little or no wind

little, Venus

_____ is hot. The greenhouse effect on _____ keeps its surface temperature at 470°C.

Venus, Venus

Why is the greenhouse effect on Venus so much stronger than on Earth?
Atmosphere of Venus
• Venus has a very _____ carbon dioxide atmosphere with a surface pressure 90
times that of Earth.

thick

The thick carbon dioxide atmosphere on _____ produces an extremely _____ greenhouse effect. Earth escapes this fate because most of its carbon and water are in rocks and oceans.

Venus, strong

Reflective clouds on _____ contain droplets of sulfuric acid.

Venus