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41 Cards in this Set
- Front
- Back
Jovian planets composition |
Jupiter and Saturn: made almost entirely of hydrogen and helium Uranus and Neptune: made mostly of hydrogen compounds mixed with metal and rock |
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Jovian planets interior structures |
Core 10x as dense as Earth, consisting of hydrogen compounds, metals, and rock |
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Jovian planets atmospheres |
Multiple cloud layers |
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Jovian planet moons |
Medium and large moons formed in the disks of gas surrounding the Jovian planets, small moons often captured asteroids or comets |
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Io |
Volcanically active, interior kept hot by tidal heating |
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Europa |
Deep, liquid water ocean under thick ice crust; interior kept hot by tidal heating |
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Titan |
Thick atmosphere made of methane and ammonia gas |
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Triton |
Orbits Neptune "backward", has the same composition as Pluto |
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Why are the Jovian planet moons geologically active? |
Tidal heating |
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What are Saturn's rings made of? |
Individual particles orbiting Saturn independently like a tiny moon |
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How were Saturn's rings formed? |
Tiny impacts on the surfaces of nearby moons and impacts that shatter the moons altogether |
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What are asteroids like? |
Small, rocky leftovers from planetary formation |
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Why is there an asteroid belt? |
Orbital resonance pushed these asteroids together |
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What are meteorites? |
Pieces of asteroids |
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What is the structure of comets and how do they get their tails? |
Comets are icy leftovers from planetary formation. When it gets close to the sun, its nucleus heats up and forms two tails |
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Where do comets come from? |
Leftovers from planetary formation |
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What are Pluto and other large objects of the Kuiper Belt like? |
Icy planetesimals |
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How great is the impact risk? |
It is unlikely that there will be a major impact within our lifetimes |
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How do jovian planets affect impact rates and life on earth? |
Impacts are almost always linked to the gravitational influences of the jovian planets |
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How do we detect extrasolar planets? |
We can look for a planet's gravitational effect on its star using the astrometric method or the Doppler method |
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What properties of extrasolar planets can we measure? |
We can determine a planet's orbital period and distance from its star |
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How do extrasolar planets compare with planets in our own solar system? |
Many orbit closer to their star, and some have properties indicating planetary types that are not terrestrial or jovian (like water worlds) |
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Do we need to modify our theory of solar system formation? How? |
It's unlikely that we will have to change to the nebular theory |
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Why does the sun shine? |
Gravitational equilibrium and energy balance |
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What is the sun's structure? |
From the inside out: Core, Radiation Zone, Convection Zone, Photosphere, Chromsphere, Corona |
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How does nuclear fusion occur in the sun? |
A proton-proton chain |
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How does energy from fusion get out of the sun? |
It comes from the deepest layers and convection carries it to the photosphere, where it is radiated into space as sunlight |
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How do we know what is happening inside of the sun? |
We do studies of solar vibrations and solar neutrinos, and observe the sun's size, energy output, and surface temperature |
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How do we measure stellar luminosities? |
We calculate luminosity from apparent brightness and distance |
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How do we measure stellar temperatures? |
By looking at a star's color spectrum (Red is cool, Blue is hot) |
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How do we measure stellar masses? |
By using Newton's version of Kepler's third law |
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What is a Hertzsprung-Russell diagram (H-R diagram)? |
Plots stars based on their surface temperatures and luminosities |
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What is the significance of the main sequence? |
It determines a star's position based on its mass (Stars with higher masses live shorter lives) |
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How does a star's mass influence its life? |
Stars with higher masses live shorter lives than stars with lower masses |
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What are giants, supergiants, and white dwarfs? |
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 |
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What are two types of star clusters? |
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 |
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How do we measure the age of a star cluster? |
We find the main sequence turn-off point on an H-R diagram of its stars |
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How do stars form? |
They form in cold, dense molecular clouds and then become a protostar |
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How massive are newborn stars? |
Can vary between 150Msun and 0.08Msun |
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What are life stages of a low-mass star? |
When the core begins to shrink, it becomes a red giant with a hydrogen shell fusion happening |
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How does a low-mass star die? |
It expels its outer layers into space and leaves its core behind as a white dwarf |