section 1 Flashcards
geocentric model
everything orbit earth in sphere patterns
proposed by aristotle
heliocentric model
what was it missing?
everything orbits sun in sphere patterns
proposed by copernicus
Kepler: orbit of planets isnt in spheres but elipses
solstice
longest/shortest day of the year
dec 21 (winter) and june 21 (summer)
equinox
2 days with equal amounts of night/day time
march 21 (spring) and sept 21 (autumn)
tools used before telescopes?
can probably skip
quadrant: measures star height above horizon
astrolabe: makes charts of star positions
cross staff: meausre angle between moon and any star
Astronomical Units
(AUs)
used for distances inside our solar system
distance: centre of the earth to centre of the sun
light years
used for distances beyond our solar system
distance: that light travels in one year (9.5 trillion km)
what are stars
what defines their colour?
hot, glowing ball of gas (hydrogen) giving off tons of light energy
hot = blue
cool = red
sun-like and massive star life cycle
birth of a star
cloud nebula - collapses n mass/temp increase when more material is drawn in
protostar - when core gets hot enough to glow
sun-like and massive star life cycle
main sequence of a star
protostar is hot enough for nuclear fusion
sun-like star life cycle
old age of a star
massive AND sunlike
star funs out of hydrogen (is dying)
stabilizes with gravity
leads to it expanding into red giant
MASSIVE; becomes red SUPERgiant
sun-like star life cycle
death and remnants of sun-like stars
core temp is too cool so it collapses on itself
shrinks untill it becomes white dwarf
fades slowly into black dwarf
nuclear fusion
hydrogen → helium
massive star life cycle
death and remnants of massive star
fusion stops and star suddenly collapses on itself (SUPERNOVA)
if it survives explosion it can be a BLACK HOLE or NEUTRON STAR
neutron star: rapidly spinning ball of neutrons
black hole: dense remnants of star with strong gravity
constellations
unoffical recognized star groups
groupings of stars seen as patterns in the night sky
asterisms
differences and similarities between ursa minor and little dipper?
can probably skip
what are two common star groups?
little dipper is an asterism
ursa minor is a constellation
ursa minor and major
galaxies
3 types?
groupings of millions/billions of stars gas and dust
elliptical, spiral, irregular
the sun
nuclear fusion happens (hydrogen collides to form helium)
order of planets
acronym?
mercury, venus, earth, mars, jupiter, saturn, uranus, neptune
my very easy method just showed you nothing
inner/terrestrial planets
small and rocky in compostion, closer to sun
earth like planets
mercury
venus
mercury: like the moon, no atmpsphere
venus: like earth (mass,size,gravity), huge greenhouse effect
earth
mars
earth: only planet that supports life, protective atmosphere (UV rays)
mars: iron oxides make it red-orange, thin atmosphere
outer/jovian planets
large + gaseous, far from sun
jovian references jupiter
jupiter
saturn
jupiter: gas giant made of hydrogen+helium, great red spot = big storm
saturn: 1000+ rings made of ice/dust, made of hydrogen + helium
uranus
neptune
uranus: hydrogen+helium gas giant, methane so it blue, big ring system
neptune: hydrogen, helium, methane, small ring system
pluto
frozen ball of methane, smaller than moon, more elliptical orbit than other planets
doesn’t fit the pattern of planets
why isn’t pluto considered a planet?
what are the three criteria
- orbits sun
- enough mass to be nearly round
- cleared the neighbourhood around its orbit
pluto hasnt cleared the neighbourhood around its orbit
comet
why does it have a tail
made of dust + ice, travels through space
when near the sun, its material is heated and releases a gas, making the tail and glow
asteroid
small, rocky, metallic bodies traveling through space
meteoroid
small pieces of rock flying through space
meteor
when meteoroid is pulled into earths atmosphere
friction causes it to shine
meteorite
if the meteor hits earths surface
solar eclipse
moon passes between earth and sun
lunar eclipse
earth passes between sun and moon
azimuth - what to know
N = 0º
E = 90º
S = 180º
W = 270º
used to find direction
altitude - what to know
0º at the horizon
90º at the zenith (straight overhead)
finds height
cannot pass 90º
