[earth science] u1 test

came into existence w/ the big bang

time matter and space

antimatter

opposite electric charge, opposite magnetic moment, same mass and lifetime (of matter)

formed when the universe began to cool down from protons and nuetrons

nuclei of hydrogen and helium

hubbles law

galaxies are moving away from earth at speeds proportional to their distance, the further the galaxies are, the faster they move away

cosmic microwave background radiation

faint remnant glow of the big bang

big bang nucleosynthesis

formation of light and atomic nuclei within the first few minutes after the big bang when nuclear fusion occured

doppler effect

apparent change in frequency of a wave caused by relative motion and source of the wave and observer
farther away a galaxy is, greater redshift, signifying a faster recession and speed from us

redshift

hydrogens spectral lines, when a light source is moving away, its spectral lines are shifted toward the red end of the spectrum

definition of a star

balls of gas made mostly of hydrogen, produce energy through nuclear fusion, classified by physical characteristics

ways astronomers classify stars

color, temperature, size, chemical composition, luminosity, brightness

what color and temperature reveal about a star

coolest stars appear red, hottest apear blue

chemical composition

most stars made up of 73% hydrogen, 25% helium, and 2% other elements

luminosity

total light energy output per second of an object that produces its own light, hotter stars produce more light

brightness

related to how much light reaches a point per second

hertzsprung-russel diagram

classify stars and how they change over time, 90% of stars are in the main sequence (including the sun)

life of a star

determined by its mass

all stars begin as a

nebula (large cloud of gas and dust that gravity pulls together to create a protostar)

small mass stars

burn slowly, live longer

when a star runs out of fuel it becomes a

redgiant or supergiant

supernova

when a supergiant runs out of fuel and explodes suddenly

nuetron stars

material left over from a supergiant explosion, very small, 3x the mass of the sun

lifecycle of a low-mass star

nebula → main sequence → red giant → planetary nebula → white dwarf

lifecycle of a high-mass star

nebula → main sequence → red supergiant → supernova ->[nuetron star (high) or black hole (very high)]

stellar nucleosynthesis

stars produce elements through this, lighter elements fuse into heavier

age of the sun

4.6 billion years old

how much hydrogen has the sun burned through

about half with 5 billion years left

how far away the sun is from earth

1 AU

how much is 1 AU

93 million miles or 150 million kilometers

how long it takes for light to reach earth

8 minutes 20 seconds

the sun’s classification

g-type yellow dwarf main sequence star

sun’s surface temperature

9,932 F

revolution

orbiting around the milky way

how long 1 revolution takes

230 million years

sun’s radius

696,340 kilometers

movement of the equator

25 days for one rotation

movement of the poles

35 days for a full rotation

layers of the sun

core → radiative zone → convection zone → photosphere → chromosphere → corona

what happens in the core

where fusion occurs by combining hydrogen and helium

what happens in the radiative zone

energy moves very slowly away from the core as photons (100,000 years to pass through)

what happens in the convection zone

plasma heats up and rises, then it cools and sinks to transport heat towards the surface

photosphere

visible surface of the sun, sunspots occur here

chromosphere

thin reddish layer where temperatures start increasing, magnetic spicules happen here

corona

outer atmosphere of the sun (over 1 million C), solar winds and coronal mass ejection occur here

fusion

joining two or more things to create a single entity

nuclear fusion

small nuclei join together to make larger nuclei, lots of energy released

energy released as

heat and light

location of heavier/denser elements

core because gravity pulls them in

fusion only happens when

theres a high enough pressure and temperature