Exam 2

The Earth's primitive atmosphere probably consisted of substantial amounts of

hydrogen

Why is the Earth's atmosphere so different from that of the other terrestrial planets?

water dissolved the CO2 and plants made oxygen

Which surface feature is found on all terrestrial planets and the Moon?

craters

Much of the water on Mars

in a layer of permafrost, locked in seasonal ice cap

Tharsis region on mars has so few craters, this suggest that

its the youngest region on the planet

which is not icy in composition

asteroidswh

ice are icy in composition

comet nucleus, Kuiper Belt objects, jovian satellites

What is true about solar system densities?

denser planets lie closer to the sun

the major presence of water detected on the moon is in

floors of deep craters

the scarps on mercury were probably caused by

crust cooling and shrinking

what characteristics of satellites give us clues about their origins?

direction, tilt, and shape of their orbits

On our moons, Mercury, Earth, and Mars, there is a variety of meteor crater sizes. Yes the ones on Venus are over 5km across. Why is this?

smaller meteors burn up in its thick atmosphere

What us the most abundant gas in Mars and Venus atmosphere?

CO2

Why is CO2 more abundant on mars and Venus than Earth?

Oceans dissolve it and life removes it

Surface features on Europa?

cracks in icy surfaceSu

face feature on Titan?

liquid methane rivers

What makes Io stand out in our solar system?

most volcanic, always changing

What drives geologic activity in terrestrial planets and moons?

internal heating- radioactivity core

Why in general do small planets have less geologic activity than larger planets?

interiors cool and solidify faster

What are exceptions to smaller planets having less geologic heating?

Some experience tidal heating

What processes shape the surface of terrestrial planets and moons?

geologic activity- plates and volcanoes, erosion, and impacts

How do we age date surfaces of planets?

number of craters

What do we mean by primordial atmospheres of planets?

original ones they formed with

what are the primordial atmospheres of planetary bodies?

H and He

Why do some planets lose their primordial atmospheres?

lighter elements reach escape velocities because smaller and warmer temperature

How do we think magnetic fields are generated in planets

metallic liquid core and fast rotation

What do we mean by differentiation

denser material in center, less dense more outward

What characteristics do all terrestrial planets have in common

rocky, differentiated structure, dense, few or no moons, cratering

What do all jovian planets have in common

massive, gas giants, low density, rings, lots of moons

how do the ring systems in jovian planets originate

objects get stuck in orbit and Roche limit

How and why did the solar system originate the way it did?

formed as a disk so planets orbit in same plane and direction

Why is the solar system laid out like that (dense inner, massive, less dense outer)?

differentiation

How and why is the solar system composed like that

further from sun, lower temp, affects other aspects

What are ways we detect exoplanets

astrometric, direct imaging, transit, radial velocity

Precisely measuring an exoplanets position in the sky and how changes over time

astrometry

nearly impossible and difficult; done directly with telescopes to find exoplanets

direct imaging

planet outside of the solar system

exoplanet

observing an exoplanet as it crosses its host star; measures depth, duration, and brightness

transit

measures the speed which an exoplanet moves towards or away from the earth

radial velocity

the distance from a star that can have water and host life

habitable zone

structure of the sun (Out to in)

chromosphere, photosphere, convection zone, radiation zone, core

How does the sun generate energy

fusion of light nuclei to make heavier ones

What are sunspots

dark, cooler sports

how do sunspots relate to energy output of the sun

related to magnetic fields

The sun is about _____ times larger than the earth

100 times

the sun's average density is roughly the same as that of

water

the sun spins on its axis roughly once each

month

AS the distance from the center of the sun increases, the density

decreases faster than temperature

appearance of cells on the sun's surface; 1000km across

solar granules

as we move further above the solar photosphere, the temperature

decreases then increases

fragments of icy material that normally orbit far from the sun

comets

spherical halo surrounding solar system; vast reservoir of cometary material

Oort Cloudpiece

s of interplanetary debris that enter earths atmosphere

meteoroids

meteoroid that reaches the ground

meteorite

where in the solar system do comets reside

Kuiper Belt and Oort cloud

parts of a comet

nucleus, coma, hydrogen envelope, tail, ion tail, dust tailco

most main belt asteroids are about the size of

small us city

asteroid groups with the smallest perihelion distances also have orbits that are

most eccentric

Spectroscopic studies reveal most asteroids contain large fractions of

carbon

Trojan asteroids on jupiters orbits are located

before and after jupiter

tails of a comet point

away from the sun

long period comet orbits can come from

all directions

Kuiper Belt objects are not planets because of their

low mass and cant clear objects

no solid surface, rotation rates differ

differential rotation

jupiters atmosphere

hydrogen

a moon placed at a planets Roche limit will

break into smaller pieces

saturns core

icy and rocky