exam 2

eight planets

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

inner planets

Mercury, Venus, Earth, and Mars

outer planets

Jupiter, Saturn, Uranus, and Neptune

inner planets characteristics

small, dense, made of primarily metal and rock

outer planets characteristics

large, tenuous, made of primarily hydrogen and helium gas

how many moons on inner planets?

no moons or perhaps few moons

how many moons on outer planets?

many moons

Do inner planets have rings?

no

Do outer planets have rings?

yes

inner planet rotation

slow

outer planet rotation

fast

The inner planets are known as

terrestrial planets

terrestrial means

Earth-like

The outer planets are known as

jovian/gas-giant planets

jovian means

Jupiter-like

All eight planets orbit the Sun in nearly

the ecliptic plane

entire Solar System is very

flat

All eight planets orbit the Sun in the same direction which is

counterclockwise

Do moons orbit the same direction as planets?

yes (counterclockwise)

Which way does the sun orbit?

counterclockwise

entire Solar System was born

roughly 4.5 billion years ago from a nebula

nebula

giant cloud of gas composed of mostly hydrogen and helium. some parts more dense , other parts less dense, tiny part of a nebula, may become dense enough that gravity dominates thus collapses toward center forming sun, rest into a flat rotating disk

The law of conservation of energy and the law of conservation of angular momentum together cause

gravitationally-collapsing material to flatten into a disk perpendicular to the angular momentum axis

Since the inner part of the protoplanetary disk was warmer only materials with

hotter melting temperatures were able to condense ie. metal & rock

Since the outer part of the protoplanetary disk was cooler

greater abundance of materials in addition to metal and rock was able to condense

condensing objects orbiting the Sun are not yet planets. They are

planetesimals, the technical word for baby planets

how did planetesimals grow?

they grew larger through accretion, the gaining of mass through sticky collisions until the planetesimals became so large that their own self-gravity became strong enough to force themselves into spherical shapes thus becoming planets

Sun is named for

Sol, the ancient Roman god of the Sun Helios

Mercury is named for

Roman god of messengers Hermes

Venus is named for

Roman goddess of love Aphrodite

Earth is named for

Terra the ancient Roman goddess of the Earth Gaia in greek

Earth's Moon is named for

Luna, the ancient Roman goddess of the Moon Selene in greek

Mars is named for

ancient Roman god of war Ares

Name of Mars moons

Phobos and Deimos

Phobos was the god of

fear

Deimos was the god of

panic

Jupiter is named for

Roman king of the gods Zeus

Saturn is named after

youngest of the ancient Roman titans Kronos

titan Saturn (Kronos) was the father of

god Jupiter (Zeus)

Uranus and Neptune were not discovered until

telescope was invented

Uranus is named after

Greek god of the sky Caelus the father of the titans

Neptune is named after

Roman god of the sea Poseidon

largest moon of planet Neptune is

Triton, named after the mythological son of Neptune

celestial body Pluto is named after

Roman god of the underworld Hades

largest moon of Pluto is

Charon, named after the boatman of the mythological river Styx who ferried souls to the underworld

most dense layer of the Earth is

core which is the most dense

earths core composed of

metal such as iron and nickel

2nd layer of earth

mantle which is less dense than the core

mantle is made of

iron-rich silicate rock

Silicates are composed of

silicon atoms, oxygen atoms, and other atoms chemically bonded to one another

outermost layer of the Earth

crust which is the least dense & thinnest layer of the Earth

The crust is also composed of

iron-poor silicate rock

center of the Earth is the inner core, composed of

primarily metal such as iron and nickel

temperature of the Earth's core is very

hot

hot temperatures should be sufficient to melt metals in core into the molten state. However..

the pressure of the inner core is so enormous that the metals are squeezed into the solid state

the inner core is also called

solid core

The layer around the solid (inner) core is

outer core

the outer core is also called

molten core

first layer of the mantle

mesosphere

second layer of the mantle

asthenosphere composed of weak solid rock

rest of the mantle together with the entire crust

lithosphere

part of earth with varying thickness. Some of these parts are so thick that they protrude out of the oceans. These very thick parts are called continents. The parts that are thin are the ocean basins at the bottom of the oceans.

lithosphere

How do we know the layers of the Earth, their thicknesses, and their compositions

using seismic waves

what causes waves that propagate throughout the entire planet

earthquakes

waves that propagate throughout the entire planet

seismic waves

device that detects seismic waves

seismometer

two different types of seismic waves

pressure waves and shear-stress waves

Pressure waves propagate faster than shear-stress waves True or False?

True

another word for pressure waves

primary waves or p waves bc they're detected first

another word for shear-stress waves

secondary waves or s waves

How can we can calculate how far away an earthquake occurred?

If the seismometer detects the S-waves a long duration of time after the P-waves, the earthquake must have occurred far from the seismometer, since the P-waves had plenty of distance to propagate far ahead of the S-waves (long delay between them). If the seismometer detects the S-waves immediately after the P-waves (short delay between them)

how are we are certain that the interior of the earth is at least partially molten?

since seismometers on the opposite side of planet Earth from an earthquake do not detect S-waves; these seismometers only detect P-waves.

which wave cannot propagate through liquid?

S-waves

P-waves can propagate through either solids or liquids T or F?

T

S-waves can propagate through either solids or liquids T or F?

F

opposite side of planet Earth from any earthquake is called

shadow zones of that particular earthquake

why is the solid part of the Earth is layered according to density

Since planet Earth was once entirely molten, more dense materials were able to sink toward the center of the planet while less dense materials were able to rise toward the surface of the planet. Most metals are more dense than most rocks. Therefore, the metals sank toward the center of the planet, forming the core. The rocks rose toward the surface of the planet, forming the mantle and the crust.

The process by which any planet separates materials according to density is called

differentiation

A planet larger than the Earth would be more

severely differentiated than the Earth

A planet smaller than the Earth would be

less severely differentiated than the Earth

Since Mars is less severely differentiated as compared with the Earth, we find even more

iron on the surface of Mars as compared with the amount of iron on the surface of the Earth.

why Mars is red?

The abundance of iron on the surface of Mars has rusted. Rust is iron oxide, which has a reddish color

Old theory about how earths magnetic field is created

Earth's magnetic field is created by the Earth's solid (inner) core. This theory may seem reasonable, since the solid (inner) core is composed of ferromagnetic metals such as iron and nickel.

Modern theory about how earths magnetic field is created

Earth's magnetic field is created by its molten (outer) core. the rotation of the Earth causes circulating currents of molten metal in the outer core. These circulating currents of molten metal in turn create the Earth's magnetic field.

two equally-important variables that create a terrestrial planet's magnetic field is

a metallic core that is at least partially molten and reasonably rapid rotation

Venus probably has a partially molten magnetic core, but it has very slow rotation. Hence

Venus has a very weak magnetic field

Mars has reasonably rapid rotation, but it has a metallic core that is no longer partially molten. Hence

Mars also has a very weak magnetic field

the only difference between the Earth's magnetic field and a bar magnet's magnetic field is

strength

bar magnet's magnetic field is thousands of times stronger than the Earth's magnetic field True or false?

True

Earth's magnetic field reverses itself once every

roughly one hundred thousand years

uppermost layer of rock has its iron magnetized in the same direction of the Earth's magnetic field; this is called

normal polarity

a deeper layer of rock has its iron magnetized in the opposite direction of the Earth's magnetic field; this is called

reversed polarity

Earth's magnetic field begins at the north pole and ends at the south pole True or False?

false

Magnetic field lines must form

closed loops. magnetic field lines of planet Earth go straight through the planet, coming out one end, circulating around to go into the opposite end, going straight through the planet, and coming out again.

t/f magnetic poles are different from the terrestrial (geographical) poles

T

Do the Earth's magnetic field lines come out from and go into the magnetic poles or terrestrial poles?

magnetic poles

t/f A magnetic compass points toward terrestrial north

False, magnetic poles

t/f the solid (inner) core is actually detached from the rest of the planet

true bc its molten and floating

t/f other planets have magnetic poles that are completely different from their geographic poles

T

a stream of charged particles from the Sun composed primarily of protons and electrons

solar wind