Review Book Ch. 3 Earth In Universe
Terms
undefined, object
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- celestial object
- any object outside or above Earth's atmosphere
- universe
- everything that exists in any place-all the space, matter, and energy in existence
- how old is the universe?
- between 10 billion and 17 billion years old
- Big Bang Theory
- states that all matter and energy started out concentrated in a small area and, after a gigantic explosion, matter began to organize into subatomic particles and atoms. within a billion years, atoms became organized into celestial bodies and then most starts became parts of gravitational groupings.
- Big Bang Steps
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a) approximately 10 to 17 billion years ago, all mass and energy was concnetrated in a small area that started expanding with a big explosion called the big bang
b) the expanding, cooling universe first formed subatomic particles and finally small atoms of hydrogen and helium
c) after approximately a billion years matter clummped together forming stars and early galaxies, and the universe kept expanding - does the universe expand or get smaller?
- expand
- evidence for the Big Bang
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1) if the big bang occured, the energy created by the explosion expanded along w/ the matter, thus there should be radiation from the Big Bang in all parts of the universe mixed w/ the energy given off by stars at later times. found evidence of long-wavelength background radiation-microwaves-that appear to be coming from all directions in the universe
2) the spectrium of the radiation emitted by stars-each element emits energy in specific wavelengths-within the electromagnetic spectrum. bc the human eye observes different wavelengths of visible light as different colors, people can distinguish specific portions of the electromagnetic spectrum. - evidence of big bang from notes (easier)
-
1. Doppler effect
a. universe is expanding
b. speed or velocity (how much lines move in time)
c. tells specific elements that are present
2. background radiation that appear to be coming from all directions in the universe - Doppler effect
- the shifting of wavelengths to either the shorter (blue end) or longer (red end) wavelengths
- what kind of doppler effect occurs if earth and another celestial object is coming closer together?
- the electromagnetic waves are bunched together, resulting in a blue shift doppler effect
- if earth and some other celestial object are moving apart, what kind of doppler effect occurs?
- a red shift doppler effect
- what does the fact that almost all galaxies have a red shift indicate?
- it indicates that the universe is expanding in all directions
- the farther away a galaxy is from earth...
- ...the greater the red shift
- what does this indicate?
- that the rate of expansion in the universe is increasing
- wavelength of galaxy not moving towards or away from earth
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the spectral lines of one element are the same as they would be if they were produced on earth
lines are in the middle of blue and red on the chart - wavelength of galaxy moving towards earth
-
light rays bunch up..wavelength is less than on earth
-blue shift
-lines on the blue side of spectrum - wavelength of galaxy moving away from earth
-
-light waves spread out..great than on earth
--red shift
--lines shift to red side of the spectrum - what is the shape of the milky way galaxy
- spiral
- how big is the milky way galaxy
- approx. 100,000 light years at its greatest diameter
- halo region of the milky way
- made up of clusters of stars that are billions of years older than our sun
- galaxy
-
basic structural unit of matter in a universe
-a collection of billions of stars and various amounts of gas and dust held together by gravity - groups of galaxies based on shapes
- elliptical, irregular, and spiral
- star
- usually a large ball of gas held together by gravity that produces tremendous amounts of energy and shines
- sun
- star that is the dominant gravitational force associated w/ earth and the rest of the solar system
- where does most of the tremendous amounts of energy produced by most stars come from?
- nuclear fusion
- nuclear fusion
- the combining of teh nuclei of smaller elements to form the nuclei of larger elements w/ some of the mass being converted into energy
- what elements does the sun convert?
- hydrogen nuclei into helium nuclei
- only under what conditions can nuclear fusion occur>
- extremely high temperatures and high pressure conditions like those found in star interiors
- where does the energy of nuclear fusion in most stars eventually go?
- it is radiated into space as type of electromagnetic energy
- luminosity of a star
- measures how bright the star would be in relation to the sun if all stars were the same distance from an observer
- which stars are smaller than earth?
- nutron stars, black holes, and some dwarfs
- how much bigger are giant stars than the sun?
- 10 to 100 times bigger
- how much bigger are super giant stars tahn the sun?
- 100 to 1000 times the size of the sun
- main sequence star properties
-
-most stars spend majority of their life as main sequence stars
-average size
-as surgace temperatures increase, luminosity increases
-luminosity increase from red to blue-white is mostly related to an increase in star size and the resulting higher temperatures - what is the smallest and coolest of stars in the main sequence
- red dwarfs
- giant star properties
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-red, organge, and yellow
-low temperature
-represent a late stage in the evolution of medium to small-size main sequence stars-when they greatly expand in size - super giant properties
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-highly luminous
-much more massive than the sun
-usually explode in a tremendous event called a supernova - blue super giants
- brightest super giant star and exhibits the highest temperature
- white dwarf properties
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-small (size of earth)
-white
-hot on the surface and low in luminosity
-last shining stage of low to medium mass stars - black dwarfs
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when a white dwarf cools and no longer emits electromagnetic energy, it is a "dead" star- a black dwarf
-when white dwarfs stop nuclear fusion and no longer produce nuclear energy - how are stars made?
-
-clouds and dust molecules created from masses that evolved from the original big bang and/or from the mass given off my stars that have expanded, exploded, or otherwise given off mass to space
-gravity causes these gas and gust clouds to clump, forming larger and larger balls
-when the mass of these balls becomes slightly larger than Jupiter, the graviational contraction results in high enough temps and pressure to start nuclear fusion
-then the ball begins to shine (radiate electromagnetic energy) and a star is born - the evolutionary stages of stars, after they spend most of their lives as a main sequence star, depends on what?
- upon their original mass
- Describe the model of star origin and evolution
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1. gas and dust clouds-->form stars when they condense
2. main sequence (becomes yellow-sun-in the middle)
3. red giant or super giant
4. MASSIVE STAR: supernova
LOW MASS: white dwarf
5. a. SUPERNOVA VERY HIGH MASS: black hole
b. SUPERNOVA HIGH MASS: neutron star
c. WHITE DWARF: black hole - solar system
- the sun and all the objects that orbit the sun under its gravitational influence
- satellite
- any object that orbits or revolves around another object
- how old is the sun?
- about 5 billion years old
- what is the gravitational center of our solar system?
- the sun
- asteroid
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a solid rocky and/or metallic body that independently orbits the sun
-have irregular shape and no atmosphere - where is a large percentage of the thousands of known asteroids
- in orbits between mars and jupiter
- what are often called minor planets?
- asteroids
- moon
- a body that orbits a planet or an asteroid as those objects oribt the sun
- comet
-
mainly composed of solids that easily change gases when heated
-when comets get near teh sun, their ices turn to gases-some solids are released, forming spectacular tails visible in earths sky - meteroriods
- very small solid gragments that orbit the sun
- meteors
- when meteroids burn up or vaporize, they leave a vrief visual streak as they pass through earth's atmosphere and are called meteors
- meterorite
- it a meteoroid survives its trip through earths atmosphere and lands on earths surface, it is then called a meterorite
- impact crater
- a depression in earths crust created by meterorites with sufficient mass that land on it
- when did our solar system start to form?
- approx. 5 bilion years ago
- how did our solar system form?
- there was a gas dust cloud bigger than the present solar system. it contained remnants of stars that had exploded. gravitiation perhaps aided by a shock wave from an exploding star, causes the cloud to condense into one or mass mass concentrations. most of the matter was pulled to the center to form the sun, which started nuclear fusion. clumping of gas and dust around it occured at the same time. larger clumps formed larger masses--forming planets, moons, and asteroids. elements having a small mass were driven out of in the inner solar system leaving the terrestrial planets w/ only small amounts of light elements.
- impact event
-
the gravitational forces of the planets pulled on the smaller clumps of matter to cause comets, asteroids, and meteoroids to collide w/ the planets in waht was called in impact events
-formed creates and have been linked to global climate changes and mass extinctions - Size (diameters) of planets
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chart pg. 41
goes up, then down, then up, then down - terrestrial planets properties
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-close to the sun
-mostly solid
-small diameters
-high densities
-rocky surfaces w/ impact craters
-few or no moons and no rings - terrestrial planets
- mercury, venus, earth, and mars
- jovian planets properties
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-far from the sun
-largely gaseous
-large diameters
-low densities
-no solid surfaces/no craters
-have many moons and rings - jovian planets
- jupiter, saturn, uranus, and neptune
- what is always one of the foci?
- the sun
- eccentricityformula
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eccentricity= distance between foci
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length of major axis - which two orbits of planets dont look lke circles to the human eye?
- pluto and mercury
- inertia
- the concept that an object at rest will tend to remain at rest, and that an object in motion will mantain the direction and speed of that motion unless an opposing force affects it
- gravitation
- the attractive force that exists between any two attractive force that exists between any two objects in the universe
- how does mass and gravitation affect each other?
- the greater the mass of one of both objects, the more gravitational attraction there is between the objects
- how does distance and mass affect each oother?
- the closer together two objects are, the greater the gravitational attraction between them
- what is the speed of light?
- 3 x 10v8 meters/sec
- properties of red waves?
- long waves w/ low energy
- how to transverse waves move?
- at a right angle
- example of short waves w/ high energy waves
- gamma rays
- constellation
- group of stars not related but form a pattern in the sky
- what stars are the hottest?
- the blue ones-youngest
- hypothesis of how solar system formed
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1. collision hypothesis--
2. nebula hypothesis-cloud of cosmic dust formed sun-particles condenses-sun dust attracted each other and planets formed - mercury propertires
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shortest year (period of revolving)
slow rotation=long day - venus properties
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day longer than its year:
rotation: 243 days revolve: 224.7 days
-rotates clockwise (backwards)
-thick atmosphere of Co2
-hottest planet
has a greenhouse effect (co2 clouds trap short rays w/ high energy) - earth properties
-
75% water
-life
-tilted 23 1/2 degrees - if there was no tilt on earth
- spring and fall all year
- if tilt of earth increased
- greater difference between winter/summer
- mars properties
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2 moons
called red planet
-has iron
-Rills Valley (carved by water) - Jupiter properties
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largest planet
10 hour day--shortest day - saturn properties
- rings
- uranus properties
- rotates on its side
- where is there a large asteroid belt?
- between jupiter and mars orbits