astronomy review Flashcards
nutation
wobble of earth’s TILT
precession
wobble of earth’s AXIS
kepler’s first law
planets orbit in an ellipse
kepler’s second law
planets move fastest when they’re closer to the sun
kepler’s third law
as a planet gets farther away from the sun, it’s revolution increases
aphelion (APART)
when earth is further away from the sun
perihelion
when earth is closer to the sun
why do we only see one side of the moon?
because the lunar day and the lunar moon is the same amount of time
waxing
getting bigger
waning
getting smaller
what would happen if the earth wasn’t tilted on an axis?
more constant climate, no seasons
what would happen if earth didn’t rotate?
no day / night
barycenter
center of gravity, center of mass between two unalike objects
spring tides (SUPER)
-when the sun, moon, and earth are in alignment
-highest high tides, lowest low tides
-new moon, full moon
neap tides
-when the moon, earth, and sun are at a right angle
-most mild tides (both high and low)
-first and third quarter
where is the magnetic force strongest?
near the poles
what is the purpose of earth’s magnetic field?
to protect earth from the sun’s harmful radiation
what are auroras?
interactions between charged particles from the sun and earth’s magnetic field
what is electromagnetic energy arranged according to?
wavelength
radio waves
longest wave length, lowest frequency, radio stations
microwaves
cell phones, microwave ovens
infrared waves
heat waves given off by warm bodies / objects
visible light
white light is a mix of light waves ith different wave lengths
ultraviolet waves
energy from the sun, sunburns
x-rays
can pass through human skin and tissue
gamma rays
shortest wave length, highest frequency. very dangerous - produced by radioactive materials and nuclear reactions
what are electromagnetic waves caused by?
fusion in the earth’s core
what are the two most common elements?
hydrogen and helium
what is fusion?
the combining of two nuclei to form another
what are galaxies classified by?
their shape
spiral galaxies
-large central bulge in the middle surrounded by stars and solar systems
-lots of dust and gas
-new stars form on the outer portion
-middle aged stars with new ones forming
elliptical galaxies
-oldest
-ovular
-largest galaxies known
-no new stars forming
irregular galaxies
-no specific shape
-can’t track the movement of stars in the type of galaxy because there is no certain shape
steady state theory
the universe is the same as it’s always been and it will always be this way
big band theory
the universe came to be when it exploded (scientists believe this theory more because they know that change is a constant in nature)
what direction does earth rotate?
counter clockwise
where does the moon rise?
moon rises in the EAST, sets in the WEST
how do lines of LATITUDE run? what do they measure?
EAST TO WEST and measure NORTH TO SOUTH
how do lines of LONGITUDE run? what do they measure?
NORTH TO SOUTH and measure EAST TO WEST
longitude affects….
timezones
latitude affects….
climates
important lines of longitude
-equator
-tropic of cancer
-tropic of capricorn
important lines of latitude
-prime meridian
-international date line
