Astronomy & Earth Science Lecture Review

A set of fill-in-the-blank flashcards covering Earth structure, seismic waves, volcanism, greenhouse effect, stratigraphy, Moon and Mars science, planetary atmospheres, cooling, and Jovian system properties.

Earth's core is solid iron-nickel, whereas its outer core is molten.

inner

__ waves (P-waves) vibrate parallel to their direction of propagation.

Longitudinal or Pressure

__ waves (S-waves) cannot travel through liquids.

Transverse or Shear

Only earthquake waves can propagate through Earth's liquid outer core.

P (pressure or longitudinal)

Because liquids resist shear, S-waves are from passing through them.

prevented

The steep slopes of a stratovolcano are due to its lava's high content.

silica

Shield volcanoes have gently sloping sides because their basaltic lava is viscous.

less

A magma "hot spot" beneath the Pacific plate created the island chain.

Hawaiian

In the Hawaiian chain, islands get as their distance from the hotspot increases.

older

As the Pacific plate moves, the hotspot currently sits beneath the island of .

Hawaii (Big Island)

In the leaky bucket analogy, incoming solar radiation is like water __ the bucket.

filling

The effect occurs when greenhouse gases trap infrared radiation.

greenhouse

Greenhouse gases warm Earth by absorbing outgoing radiation.

infrared

Water vapour, CO₂, CH₄, and N₂O are all gases.

greenhouse

Burning fuels rapidly adds ancient carbon to the atmosphere.

fossil

Steno's Law of Horizontality states that sedimentary layers are initially flat.

Original

Steno's Law of Continuity says layers extend over large areas until interrupted.

Lateral

According to the Law of , younger layers lie above older ones.

Superposition

The Law of relations states that a feature cutting a rock is younger than the rock it cuts.

cross-cutting

We always see the same lunar face because the Moon's rotation is -locked to Earth.

tidally (synchronous)

A lunar day (sunrise to sunrise) lasts about Earth days.

29.5

Lunar daytime temperatures can reach about °C.

123

Lunar nighttime temperatures can fall to about °C.

-153

The early, impact-rich era of the Solar System is called the bombardment period.

heavy

The model of lunar origin best explains the Moon's observed properties.

giant impact (collision)

On Earth, tectonic activity and erase many ancient impact craters.

erosion

Liquid water is scarce on Mars today partly because surface ice directly to vapour.

sublimes

Dendritic valley networks on Mars indicate past flow.

liquid water

A "splosh" crater forms when an impact melts subsurface , creating muddy ejecta.

ice

Low neutron flux measured from orbit suggests Martian soil rich in .

hydrogen (water)

__-penetrating radar has detected subsurface ice deposits on Mars.

Ground

A planet needs sufficient , moderate temperature, and a magnetic shield to retain an atmosphere.

mass

Cooling time scales with volume-to-surface ratio, so small bodies cool .

faster

A strong field, produced by a rotating liquid metal core, helps protect atmospheres from solar wind.

magnetic

Jupiter and Saturn contain a layer of hydrogen not found in Uranus or Neptune.

metallic

The blue colour of Uranus and Neptune is caused by atmospheric absorbing red light.

methane

Uranus experiences extreme seasons because its axis is tilted about °.

98

Jovian planets' numerous moons are mostly due to their strong attracting surrounding debris.

gravity

Io's intense volcanism is powered by heating from Jupiter's gravity.

tidal

Europa's induced field implies a subsurface salty ocean.

magnetic

Titan is unique for having a thick atmosphere rich in and surface lakes of hydrocarbons.

nitrogen (and methane)

Small icy moons stay geologically active because ice melts at temperatures than rock.

lower

Jovian planet rings are continually replenished by dust from impacts on .

moons

The mantles of terrestrial planets are composed primarily of solid rocks.

silicate