Astronomy Exam 3

Radiative ZOne

.2 to .7 energy is transported in photons instead of gases because the sun is just so hot that the bulk motion of gas wouldn't work. photons are can only go a short distance before they are absorbed by another particle or scattered. THis is why it takes so long for a photon to radiate out from the sun, because it has to fight its way through all the stuff and get out.

Convective zone

.7 to 1 of the sun. this is where photons are too bulky to move anymore because they have absorbed so much that they just cycle up and down now. plasma is not dense enough or hot enough that transfer of energy by raidation will work. THe sun is boiling through convection currents and the granules appear

Period of variation of sunspots

11 years, and the magnetic field changes every 11 years as well.

asteroid beltm

2 AU to 3.5 AU between the orbits of mars and jupiter

sun rotation period at equator

24.5 days

Magnitude +2

2nd group to be visible after the sun sets. Note: the greater the apparent magnitude the dimmer the star

sun rotation period at poles

35 days

venus and volcanoes

80% of venus is made of flat plains that are volcanic in orgins. volcanoes are spread evenly throughout venus. no plate tectonics but young surface. it is to flaky to have plate tectonics, it has an active molten interior that causes little convection cells and makes the crust flake. the surface is so hot the lithosphere flakes. sulfur on venus either due to real volcanoes or outgassing or lightning we can't really tell with the thick atmosphere

90% and 10%

90% Particles of Hydrogen and 10% particles of Helium is the breakdown of the universe

greenhouse gases

CO2, H2O, and CH4. They absorb light in the infrared area of the spectrum and then reemit it. the balance between earth and sunlight is perfect. We emit what we take in and keep a little bit more just because we are making some infrared in the atmosphere.

2 Step in Creation of our galaxy

Disk develops (proplyd) and a Protosun forms. THe gas before hand was moving but as it collapses it moves faster (class demo) and causes the gas to spin faster and faster around the axis of rotation. Disk forms perpendicular

75% and 25%

Hydrogen is 75 and Helium is 25. This is what the universe is made out of. 2% is metals

.Why did Jupiter hit first

Jupiter was the first planet to form because it was right outside the frost line where it could accrete ice but there was also more ice and rock here than farther out. It could form the core it needed faster than the other planets so it captured the most gas to form the seed. Neptune and Uranus were just lucky enough to develop and form before they were taken out.

Prominences

Magnetic fields push upward from Sun's interior compressing and heating a portion of the choromosphere that appears as bright arching columns of gas

Kepler and Newton

Newton improved some of kepler's law. He added mass to kepler's third law. the less massive an object the faster it moves around the sun

Newton explains the secret of our heliocentric solar system

The third law says that two objects exert an equal and opposite force on each other. Though the sun and the planets have the same force on each other the sun is just way more massive than the planets so the planets experience the greater acceleration and not the sun.

Venus and the runaway greenhouse effect

Venus once had oceans like earth. It was full of water and this water evaporated and formed greenhouse gases in the atmosphere but not at an alarming rate. Volcanoes were also giving off carbon and sulfur. Soon though as the sun increased in its energy output venus's water evaporation grew and grew and grew. It all evaporated becoming greenhouse gases that trap all the light from the sun in. However, there is no water on venus because the h2o molecules are split apart in the atmosphere and hydrogen escapes but not the oxygen, so you are left with oxygen and carbon from the volcanoes and sulfur from the volcanoes to make a really inense atmosphere.

runaway icehouse effect

a decrease in temperature would have caused a further decrease in temperature. mars is a good example. The only real carbon it had came from volcanoes, but as mars cooled the hot spots on mars died because the interior was no longer molten. This caused the volcanoes to stop emitting carbon, and without carbon a greenhouse atmosphere couldn't have formed trapping heat, so the planet just got colder and colder because the inside wasn't hot anymore. the atmosphere on mars does exist but it is super thin. MOst of the atmosphere is made from carbon dioxide and nitrogen, so co2 does create a greenhouse effect, but it is a very weak one.

Sunspot max

a period of a lot of sunspots

sunspot min

a period of not so many sunspots

planet's surface gravity

acceleration

how bright a star appears is not

always a good indicator of its distance

Newton's First Law

an object remains at rest, or moves in a straight line at a constant speed, unless acted upon by a net outside force. this is important to the planets because if the planets had no net outside force acting on them they would just move a constant speed in a straight line out into space, but we know that they orbit the sun. This means they must have some net outside force acting on them to make them change.

everything on the periodic table beside H and HE

are called metals

Oceanic crusts

are younger than continental crusts because they are more dense and therefore they always subduct and get destroyed creating new crust. new crust forms at ocean rigids and dies at plate boundaries. continents are only destroyed through erosion

hydrostatic equilibrium

balanced equlibrium of a star. density as you go down keeps it from collapsing on itself or getting hotter or cooler

why are craters round

because of impact waves that make it round on the moon

Convection Zone

beyond .71 R. radiative diffusion doesn't work here so convection kicks in with cold air lowering and hot air rising.

why hydrogen and helium?

big bang, that is all that survived. Everything else came from a dying star

granule

blotches on the photosphere. each is about the size of texas and oklahoma put together.

asteroids

called minor planets because there is no dividing line between them and planets. only the largest asteroids are round because they have enough mass for gravity to pull it into a round shape. These are the leftover remains of the formation of the solar syste

S waves

cannot travel through liquids proves that earth has a molten core. Only p waves can travel through liquid and that is what scientists on the other side of the world feel when there is an earthquake

Differential rotation and sun spots

causes the magnetic field in the photosphere to become wrapped around the sun. Convection creates kinks in the field nad they erupt through the solar surface causing sun spots

1st step in creation of our galaxy

collapse a clump of gas and dust within a cloud. High density means more gravity and material falls towards the center of mass. Converts into kinetic energy as it falls faster and faster. Kinetic energy is transfered into thermal energy as gas and dust collide. the temperature gets hot, fast, and becomes like the sun

Giant planets composition

core of metal, rocks, and ice. Atmosphere of helium and hydrogen, mantles of ice and water, methane, and ammonia. metallic hydrogen shell

Mars and water

could have life because it used to have lots of water on it. RIvers and water deposits show that. we have also found ice on mars. We haven't found any life though. Mars is too cold now to have water in a liquid form. It can either exist as a solid (ice caps at poles or under the surface), or as a gas (clouds) but it is not warm enough or have enough pressure to make it liquid.

coronal holes

dark areas of sun where winds are escaping

Difference in planet size and composition is

due to the temperature in the disk

what drives plate tectonics

earth's escaping heat

the brightest stars

emit more energy

before newton results were

empirical or based on observations. No one knew why the planets did what they did. THey just know that they did stuff. Newton came along and changed this. he developed laws that were theoretical and that could be applied to all space objects. they were proven

Jovian planet characteristics

enormous, gas, very low density, rings, many moons, far from the sun, seperated by large distances from each other

Magnitude +1

first group of stars visible as the sun sets below the horizon

Radiative zone

from the center of the sun out to about .71 R energy is transported by radiative diffusion. this is where photons travel but it is extremely dense to it takes the photons a long time to travel. so the energy we are getting from the sun is hundreds of thousands of years old

carbon molecules

give life to places. They are found in meteorites and comets which brought carbon to planets when they crashed into the planets. it could also be made through early atmosphere in early solar system. It can come through a mix of hydrogen and ammonia, and methane, and water vapor.

Metiallic Hydrogen

high pressures squeeze hydrogen atoms so close together that electrons can move freely from atom to atom. The magnetic fields on jupiter and saturn come from these electrons moving freely.

Apparent Magnitude

how bright an object appears to an earth-based observor

Dip width

how long the transit takes wider dip=longer orbital period

Dip Depth

how much light is being blocked. Deeper dip=larger planet

helioseismology

how we understand the inside of the sun. We detect shakes and waves in the sun to find what it is like inside of it

Kepler's third law

if two planets are orbiting the sun then the one that is farther away is going to take longer to orbit because its orbit will be bigger

Newton's Second Law

in order to give an object an acceleration (that is to change its velocity) a net outside force must act on the object F=ma

pangaea

in the past all the continents where smushed together to create one giant land mass. the trapped heat under continent would start convection going and that would cause plate boundaries to move apart. at the boundaries of these plates that is where you find earthquakes, mountains, volcanoes, uplifts, and trenches.

Speed

is a meausre of how fast an object is moving

weight

is the force of gravity that acts on a object

Radioactive Decay

it drives earth's plate tectonics because it is the cause of primary heat. It is the breakdown of elements

Earth's early atmosphere

it first started out as hydrogen and helium when it was in the solar system formation. then the solar wind blew these gases away and we were left with an atmosphere of co2 from our own volcanic activity. now we are mostly made up of oxygen and nitrogen due to life

Newton's third law helps us discover extrasolar planets

it helps us because if a massive planet is close to the sun then the distance between them is smaller and therefore the amount of gravity the planet is going to exert on the sun is going to be greater causing the sun to wobble in the sky. Stars only wobble if there is a planet close by and that is how we find planets. It's the idea of putting jupiter where earth is and because it is so much more massive it is going to wobble the sun because the gravity between the two is going to be greater due to mass and distance.

sunspot

it is an irregularly shaped dark region in the photosphere. It is where temperature is relatively low in the photosphere. magnetic fields get really concentrated in one spot and then push the plasma away creating a little hole in the photosphere

The corona

it is only seen during eclipses, because you have to be able to block the photosphere to see it. Air itself isn't very hot because it doesn't have a lot of atoms because it is a vacuum. But these atoms are moving very fast and that is what causes heat. it is super duper hot like over a million kelvins hot

Mars' core

it's too small to have a liquid core and there have been no geological activities on it so it is solid

life changes

its environment

Europa

jupiters moon with an ocean underneath its surface.

thermal equillibrium

keeping the sun's interior from cooling down by equalizing how the energy from the interior gets to the surface and is radiated out into space.

needed for life on a planet

liquid water

Mercury's core

makes up 70% of its mass. it's solid iron

microwaves

mapped venus's surface since the atmosphere is so dense we can't see through it.

mars and volcanoes

mars has no plate tectonics but it did once have an active, molten interior that caused volcanoes to form due to hot spots. the magma would rise up to the surface because they were on top of hot spots and that built up volcanoes. today mars has cooled because it is not large enough to hold onto that heat so it is geologically dead. but huge rift valley and canyons have formed because stresses on its surface caused it to crack. its the size of the usa. it has craters but some of them probably got wiped out when there were volcanoes.

Godlilocks Effect

mars is too cold to have liquid water, venus is too hot to have liquid water (it can only be a gas), and earth is just right. We can have water in liquid, gas, and solid form which is essential to life.

density: what is it?

mass/volume. what determines density the types of atoms in the material. how the atoms are arranged on a atomic level too

mass

measure of the total amount of material in the object

parallax

measures stellar distances. The apparent displacement of an object because of a change in the observers' point of view.

Kepler telescope

measures the transits of planets across stars

Coronal mass ejection

more than 10 to the 12 kg of high temperatures. coronal gras is blasted into space at high speeds. comes from large scale alterations in sun's magnetic fields

characteristics of planets

needs to be in orbit around our sun, needs to have enough mass to have gravity turn it into a sphere, needs to have cleared the neighborhood around its orbit

characteristics of dwarf planets

needs to be round, orbit the sun, has not cleared its orbit, and is not a satellite.

most common elements come from

nuclear fusion and that is what makes up most of the universe

solar wind

outflow of escaped gas from the sun. the sun can mostly hold on to its gas due to its gravity but sometimes things escape because it is so energetic.

Radiative diffusion

photons emitted from the thermonuclear inferno at the star's center spread outward toward the star's surface. These photons are absorbed by electrons and atoms inside the star. The overall result is an outward migration from the hot core.

Sunspots

places where the sun's plasma is bathed in a concentrated magnetic feild that pushes plasma away and makes it cooler.

4th step in the creation of our galaxy

planetismals grow large in size to become protoplanets (around 1 km) 1 km is when you can use gravity to get more material. Planets start to clear their orbitals

3rd step in creation of our galaxy

planets form through accretion. collision course planets. Gases don't accrete. H and He are everywhere in the solar system

Indirect Detection Technique-Radial Velocity

planets that are big and close to their star in the sky will make the star wobble which we can pick up using the doppler shift. the time it takes for the cycle to repeat itself in the graph shows me the orbital period. The higher the amplitude of the velocity, so how the star is changing, tells me the size of the star.

asthenosphere

plastic flow. where the covection currents churn and churn as they go up and down. is about 10% molten which is super important because that means that there is liquid that can undergo convection and cause the plates to move

earth is the only planet with waht

plate tectonics

primary and secondary sources of earth's heat

priamry-radioactive decay, secondary-formation heat

thermonuclear fusion

process of changing hydrogen into helium in the sun. can only take place in extreme heat because all atomic nuclei have a positive electric charge and so tend to repel one another. But in extreme heat and pressure they are forced to combine with each other

proplyds

proto-planetary-disks

neutrinos

protons that turn into neutrons and let out little particles

5th step in the creation of our galaxy

protoplanets collide, some are destroyed and are the ones surviving who have cleared their orbitals of everything massive are the ones we consider planets

Absolute magnitude

quantity that relfects a star's true energy output. Measure of the star's total light output

most common way to find planets

radial velocity

lithosphere

rigid plates

spicules

rising vertical spikes of gas jets

Inverse square law

says that the closer the object the brighter it will be

inner terrestial planet characteristics

small, high density, made of metals, close to sun, have few moons, no rings, made of rocks,

Model of the Solar Cycle

solar minima-the magnetic fields start parallel to the rotation of the sun. torodial field-but the poles rotate slower than the equator so the magnetic field starts to wrap around the sun. solar maxima- the field is all loopy now due to differential rotation. magnetic fields break through the surface causing sunspots and flares. 11-years the magnetif field lines break and reconnect until they are parallel again. sunspots are observed at the poles first and then move toward the equator

Core of the earth

solid iron and liquid iron outer core

crust

solid rock on top of earth. this is what undergoes plate tectonics

velocity

speed and direction of motion

Chromosphere

sphere of color, not dense at all. Dominated by emission lines. Ha molecules are at the red end of the spectrum and make up the chromosphere giving it a pink haze. Helium was first discovered here. Temperatures increase as you increase the height.

Photosphere

sphere of light appears to us to be the definate surface. This is the line and anything below it is the sun's interior and above it is the atmosphere. It is opaque or we would be able to see thorugh it. It is made of H and He. Temperatures increase as you go down

Zeeman effect

splitting of spectral lines shows us where the magnetic fields are intense and atoms are subjected to the field

sun's rotation

takes about 4 weeks

Core of the Sun

temperature and pressure are high enough to fuse hydrogen into helium. rate of fusion relies heavily on pressure-depends on the mass because gravity is trying to collapse the star. the huge amounts of energy being created in the core is what is keeping the sun from collapsing on itself from gravity. extends from 0 to .2

sunspot cycle

the average number of sunspots varies with a period of about 11 years. sunspots don't move the magnetic field moves creating sunspots first towards the poles and then to the equator. a sunspot dies where it was born.

the sun's energy is made where

the core. this is where nuclear fusion takes place and hydrogen is made into helium

Density of Space stuff

the further in the more material you have in the disk. The outer regions are kind of barren because they don't have a lot. This explains why neptune and uranus are smaller than jupiter and saturn. THe inner planets are small because the temperatures are too great for ice, but they took in all the metal they could around there.

The closer the object you are viewing

the greater the parallax shift.

Oort cloud

the halo around the solar system where a lot of comets hang out

what gases a planet can hold onto depends on what

the mass and the temperature

differential rotation

the polar regions of the sun rotate slower than the equator regions of the sun.

acceleration

the rate at which velocity changes. acceleration can result in a change of speed or direction. can only be caused by unbalanced forces. If the forces cancel out nothing will happen

the amount of energy we receive from the sun

the same amount it pushed back into space. We are always at an equillibrium. when global warming isnt a thign. likewise the amount of energy the earth emits is the amount is absorbs. everything is equal.

the larger the planet's orbit

the slower the planets speed because the gravitational attraction between the sun and planet is less. think of ball on the string idea, having a longer string takes less effort to whirl the ball around than a short one

Plasma

the solar atmosphere is made of this and it is where charged ions and ectrons can move freely causing a magnetic filed

molecular clouds

the star dust that comes from a dying star and starts to build new galaxies

Preceding members

the sunspots that go to the equator and just balance out.

Following members

the sunspots that go to the poles and follow behind the preceding members. these guys change the magnetic field of the sun every 11 years

orbit times

the time it takes from one dip to the other. the time between the dips is longer than the dip itself

Dip sidest

these are sloped

Sun spots polarity

they are charged according to what hemisphere they are in and the poles associated with that hemisphere

what are granules and how are they made?

they are light colored patches that make up the photosphere of the sun. they are made by the convection patterns of the sun where hot air rises and cool air sinks. the hot air are the bright spots

Trans Neptunian Objects

they hang out in the kuiper belt whcih is 30 to 50 AU away from the sun. THe largest of these objects are dwarf planets like pluto. they are much more numerous than asteroids because ice is everywhere in the solar system

how do planets get so close to their star

they spiral into it because the disk loses grip because of friction and then they just get close. Eventually they don't fall into the star because of gravity

How the JOvian planets work and are made of gas

they work because they have cores who were built with ice which is really abudent. they got the ice because they were outside the frost line. Once they had a huge core things just kind of escalated till they collected a bunch of gas.

dip bottom

this is flat

continent and continent collision

this is what builds up mountains because the two don't really subduct under each other. plates just pile up and wrinkle

why study exoplanets

to know more about how the solar system might have formed.

luminosity

total amount of energy a star emits

magnitude scale

used to denote the brightness of stars

Venus and mercury magnetic fields

venus does not have a magnetic field which is surprising because it is roughly the same size as earth. we think it might not have one just because it is so slow to rotate that the field can't churn and work. but mercury which is way smaller has a magnetic field which is pretty crazy, but that is because the iron core is so huge and some of it must still be molten for it to have a field.

Direct Imaging of planets

very difficult because we have to line up just right to be able to tell the star apart from the planet.

solar flares

violent, erruptive spew out radiation and such into space creating a ripple effect like in a pond

Transit method

way of figuring out the orbit of planets by detecting a decrease in brightness of a star. You can tell the size of the planet by how much light decreases, and the orbit of the planet by how frequent the decrease in brightness becomes

earth and magnetic field

we have a magnetic field because we have a solid iron core, but also a molten iron core that creates magnetic field lines. the magnetic field is so important though because it deflects a lot of the harmful substances coming from the sun aimed at us.

Comets

when two objects in the kuiper belt hit each other and a gragment is knocked off into a new and elongated orbit. when it gets close tot he sun the sun vaporizes some of the ice and that produces a long flowing tail of gas and dust

Newton's Third Law of Motion

whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object. Force pairs and two objects. they are just exerting the same amount of force on each other

T tauri

winds that come from the sun that helped to clear the orbitals of planets

if you drop a hammer and a feather on the moon will they hit at the same time

yes, but why? the hammer has more mass than the feather. That's the key because the hammer has more mass than the feather and it is therefore going to resist accelerating more than the feather. On earth they don't fall at the same time because of air resistance but since the moon has no atmosphere it is not going to have that resistance and will fall at the same time as the hammer.

above hot spots

you find volcanic island, chains, or mountain ranges