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54 Cards in this Set
- Front
- Back
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how old is the universe |
10-17 billion years oldq |
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how did the universe begin |
scientists believe it began with a big bang |
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steps of the big bang theroey |
1. super hot and dense tiny mass expanded quickly and later slowed 2. 300,000 yrs went by ... universe began to cool and the atoms clumped into clouds of gases forming galaxies 3. 1st stars formed (mostly H. and some He. ) and eventually our sun and 8 planets from this interstellar matter: gas and dust |
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evidence for the big bang event |
Radiation (long-wavelength radiation)
*in the form of microwaves *found in all parts of the universe *produced by the big bang explosion
A red shift in the doppler effect
*caused by light energy from the stars *indicates that the universe is expanding in all directions * the farther away a galaxy is from earth, the greater the red shift - this indicates that the rate of expansion is increasing |
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what is the red shift |
the EM spectrum (electromagnetic spectrum) shows wavelengths of energy Different energy has different wavelengths which are represented by different colors esrt pg 14 |
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scientists infer which elements are present in celestial objects based on what |
the wavelength emitted and they compare wavelengths emitted from earth with other objects |
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if celestial objects are coming together there would be a what |
blue shift contracting universe |
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if celestial objects are moving apart there would be a what |
red shift expanding universe |
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structure of the universe |
*scientists infer the universe's structure through the use of the Hubble space telescope *the basic unit of matter in the universe is the universe *there are approx. 100+ billion galaxies |
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the galaxy |
consists of approx. 100 billion stars
there are 3 galaxy types |
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what are the three galaxy types |
elliptical
irregular
spiral |
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stars |
*large balls of gas *held together by gravity *produces huge amounts of energy |
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how does the galaxy produce huge amounts of energy |
nuclear fusion
2 H -----> 1 HE
nuclear fusion ----> energy ----> EM energy radiated into space |
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it takes energy to do what |
to shine |
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stars shine |
*we observe the apparent brightness (luminosity of a star *color is very important in classifying stars
star temp cooler ----> Hotter
star color red ---> yellow ---> white---> blue
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types of stars |
main sequence stars super giants white dwarfs black dwarfs |
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main sequence stars |
*average size stars *as their surface temp increases their luminosity increases *90% of stars are main sequence stars *stars spend most of their life as main sequence stars *the smallest / coolest / most common type of main seq. star= red dwarfs *our sun is a main sequence star its yellow |
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giant stars |
d*10x's the size & luminosity reds, oranges, and yellow * great size & luminosity: reds, oranges, and yellows * the sm/med. main sequence stars ---> increases in size (expand) ---> become low temp. giant stars |
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super giants |
*100-1,000x's the size of the sun's diameter
ex. blue super giant = highest temp / luminosity *super giants ---> explode ---> become a super nova |
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white dwarfs |
*not all are white *about the size of earth *hi temps... lo luminosities *they aare the last shining stage : ( |
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black dwarfs |
*very common *they are cooled white dwarfs that emit no EM energy |
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evolution of a star |
*gas and dust molecules were produced from the big bang and / or star explosions; gravity causes the molecules to clump, contract, & the temp increases ... nuclear fusion occurs!! *nuclear fusion continues ---> shining occurs ( radiates EM energy) *most of their life is at this stage billions of years *main sequence stars grow into super giants *the mass is similar to the sun ---> 5b ---> 6c ... billions of yrs. - longer time. The mass is greater than 1.5x's the sun 5a 6a / 6b ... 100 thous. years - shorter time.
6a and 6b are very dense |
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Parts of the solar system |
sun planets asteroids moons comets meteoroids meteorite
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sun |
*medium sized star *5 billion years old *makes up 99% of the solar systems mass
** there are many satellites in the solar system |
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satellites |
objects that orbit / revolve around another objec. + (sun)
ex. satellites of the sun are: planets, asteroids, meteoroids, and comets. *satellites of planets would be a moon
Q: how many satellites does earth have A: one natural satellites and 2,500 artificial satellites |
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planets
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-usually spherical in shape
-there are 9 planets in our solar system ( counting Pluto) -there are approx 100+ planets revolving around other stars not the sun that's our sun. |
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planets in order |
Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune |
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asteroids |
*rock like masses; revolve around the sun *irregular in shape ... larger ones are spherical *smaller than planets *over 1,000 asteroids exist and most occur in a belt between mars and jupiter |
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moon |
esrt pg. 15 *over 100+ moons exist they vary in size *satellite of the Earth |
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comets |
*large balls of icey water and methane with rocky / metallic solids *1-100km in diameter |
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meteoroids |
*small solid fragments *most are the size of a dime / grain of sand *meteoroids ---> pass through our atmosphere ---> meteors steak *meteoroids - if they don't burn up ...are called a meteorite ...they hit the earth and create an impact crater |
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evolution of the solar system |
*a shock wave ( from an exploding star) started a gravitational contraction of a gas / dust cloud *matter was pulled to the center ...and the sun was formed ... WOW, nuclear fusion begins: clumping of additional matter around the sun continues *the clumping continues to form Large Masses such as moons, asteroids, + planets ** comets, asteroids, and meteoroids collided with planets forming craters ...this "smash" is known as an impact event. |
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impact event |
linked to global climate changes and mass extinctions **newly formed planets and moons melted as a result of contraction, radioactive decay, and frictional heat (from the impacts) ** this melting causes the planets to form into layered bodies based on the density of the material ...for instance, the more dense material sinks to the center of the planet |
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planet characteristics |
the suns radiated energy and Hi temp and pressure caused the less dense elements to be driven farther away deeper into the solar system |
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terrestrial characteristics |
*close to sun *mostly solid *small diameters *high densities *few / no moons *rocky surface / craters *includes 4 planets |
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Jovian characteristics |
*far from the sun *mostly gaseous *large diameters *low densities *many moons *no craters *some rings *includes 4 planets |
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it takes how many years to make one trip around the world |
225 million |
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planets rotate on their what |
axis |
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planets revolve around the sun in a(n) what |
orbit (path) |
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day and night |
rotation 7 out of 8 planets rotate in the same direction |
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one year |
revolution - the orbits are eccentric |
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the shape of an orbit is known as a(n) |
ellipse |
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scientists measure the what |
eccentricity |
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eccentricity |
the degree of roundness of orbits |
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eccentricity ranges from what to what |
0 to 1 |
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as E increases ...the orbit becomes more what |
flat |
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do most orbits have and oval or a circular shaped orbid |
circular esrt pg 15 |
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the closer to zero the eccentricity gets the more _____________ the shape of the orbit gets. |
circular |
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perihelion |
Jan 3 increased orbital speed |
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aphelion |
july 4 decreased orbital speed |
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as mass of an object increases |
gravity increases |
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as the distance between the 2 objects decreases |
gravity increases |
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the orbit of a planet around the sun is maintained by dynamic equilibrium
what is dynamic equilibrium |
a balance (that includes motion) btw. Inertia & gravitation |
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as the distance to the sun increases |
orbital size increases period of revolution increases speed of revolution decreases orbital speed decreases |
