Ast Exam 3

Front 1

Jovian planets composition

Back 1

Jupiter and Saturn: made almost entirely of hydrogen and helium

Uranus and Neptune: made mostly of hydrogen compounds mixed with metal and rock

Front 2

Jovian planets interior structures

Back 2

Core 10x as dense as Earth, consisting of hydrogen compounds, metals, and rock

Front 3

Jovian planets atmospheres

Back 3

Multiple cloud layers

Front 4

Jovian planet moons

Back 4

Medium and large moons formed in the disks of gas surrounding the Jovian planets, small moons often captured asteroids or comets

Front 5

Io

Back 5

Volcanically active, interior kept hot by tidal heating

Front 6

Europa

Back 6

Deep, liquid water ocean under thick ice crust; interior kept hot by tidal heating

Front 7

Titan

Back 7

Thick atmosphere made of methane and ammonia gas

Front 8

Triton

Back 8

Orbits Neptune "backward", has the same composition as Pluto

Front 9

Why are the Jovian planet moons geologically active?

Back 9

Tidal heating

Front 10

What are Saturn's rings made of?

Back 10

Individual particles orbiting Saturn independently like a tiny moon

Front 11

How were Saturn's rings formed?

Back 11

Tiny impacts on the surfaces of nearby moons and impacts that shatter the moons altogether

Front 12

What are asteroids like?

Back 12

Small, rocky leftovers from planetary formation

Front 13

Why is there an asteroid belt?

Back 13

Orbital resonance pushed these asteroids together

Front 14

What are meteorites?

Back 14

Pieces of asteroids

Front 15

What is the structure of comets and how do they get their tails?

Back 15

Comets are icy leftovers from planetary formation. When it gets close to the sun, its nucleus heats up and forms two tails

Front 16

Where do comets come from?

Back 16

Leftovers from planetary formation

Front 17

What are Pluto and other large objects of the Kuiper Belt like?

Back 17

Icy planetesimals

Front 18

How great is the impact risk?

Back 18

It is unlikely that there will be a major impact within our lifetimes

Front 19

How do jovian planets affect impact rates and life on earth?

Back 19

Impacts are almost always linked to the gravitational influences of the jovian planets

Front 20

How do we detect extrasolar planets?

Back 20

We can look for a planet's gravitational effect on its star using the astrometric method or the Doppler method

Front 21

What properties of extrasolar planets can we measure?

Back 21

We can determine a planet's orbital period and distance from its star

Front 22

How do extrasolar planets compare with planets in our own solar system?

Back 22

Many orbit closer to their star, and some have properties indicating planetary types that are not terrestrial or jovian (like water worlds)

Front 23

Do we need to modify our theory of solar system formation? How?

Back 23

It's unlikely that we will have to change to the nebular theory

Front 24

Why does the sun shine?

Back 24

Gravitational equilibrium and energy balance

Front 25

What is the sun's structure?

Back 25

From the inside out: Core, Radiation Zone, Convection Zone, Photosphere, Chromsphere, Corona

Front 26

How does nuclear fusion occur in the sun?

Back 26

A proton-proton chain

Front 27

How does energy from fusion get out of the sun?

Back 27

It comes from the deepest layers and convection carries it to the photosphere, where it is radiated into space as sunlight

Front 28

How do we know what is happening inside of the sun?

Back 28

We do studies of solar vibrations and solar neutrinos, and observe the sun's size, energy output, and surface temperature

Front 29

How do we measure stellar luminosities?

Back 29

We calculate luminosity from apparent brightness and distance

Front 30

How do we measure stellar temperatures?

Back 30

By looking at a star's color spectrum (Red is cool, Blue is hot)

Front 31

How do we measure stellar masses?

Back 31

By using Newton's version of Kepler's third law

Front 32

What is a Hertzsprung-Russell diagram (H-R diagram)?

Back 32

Plots stars based on their surface temperatures and luminosities

Front 33

What is the significance of the main sequence?

Back 33

It determines a star's position based on its mass (Stars with higher masses live shorter lives)

Front 34

How does a star's mass influence its life?

Back 34

Stars with higher masses live shorter lives than stars with lower masses

Front 35

What are giants, supergiants, and white dwarfs?

Back 35

Giants and Supergiants: stars that have exhausted their central core supplies of hydrogen for fusion and are going through different forms of fusion near the end of their lives

White Dwarfs: the exposed cores of stars that have already died

Front 36

What are two types of star clusters?

Back 36

Open clusters: contain up to thousands of stars and are found in the disk of the galaxy

Globular clusters: contain hundreds of thousands of stars and are found in the halo of the galaxy

Front 37

How do we measure the age of a star cluster?

Back 37

We find the main sequence turn-off point on an H-R diagram of its stars

Front 38

How do stars form?

Back 38

They form in cold, dense molecular clouds and then become a protostar

Front 39

How massive are newborn stars?

Back 39

Can vary between 150Msun and 0.08Msun

Front 40

What are life stages of a low-mass star?

Back 40

When the core begins to shrink, it becomes a red giant with a hydrogen shell fusion happening

Front 41

How does a low-mass star die?

Back 41

It expels its outer layers into space and leaves its core behind as a white dwarf