unit 7 earth sun and moon

rotation

The action of spinning an object around an axis

1 rotation equals

1 day or 24 hours

revolution

1 full orbit around the sun

1 revolution equals

1 year

the tilt of the earth

causes seasons

23.5 degrees

why the tilt of the earth causes seasons

1. sunlight hits the earth more directly on the part facing the sun

2. longer days

northern vs southern hemisphere

when it is summer in the northern hemisphere, it is winter in the southern hemisphere

when 1 part of the earth is pointed towards the sun, the other is pointed away

Summer in the northern hemisphere

is winter in the southern hemisphere

spring and fall

in these seasons, the northern and southern hemisphere receive equal amounts of sunlight

change of daylight hours

change of daylight hours throughout the year

is greatest at the poles

least near the equator

aka near the equator the days don’t get as short in winter

which part of the earth is it summer

depends on the part of the earth that is tilted towards the sun

apparent size

size as seen from earth

the moon and sun have similar apparent sizes

phases of the moon

the very predictable pattern of what the moon looks like from the earth

two major features of the moon

highlands and maria

highlands

lighter, raised areas of the moon

has a lot of craters from impacts with asteroids

maria

latin for sea

darker, low areas formed by lava cooling down

Has less craters due to being younger rock

tidal locking

when one side of the moon always faces the earth

time for 1 orbit = time for 1 rotation

near side of the moon

the side of the moon that is always facing us on earth

far side of the moon

the side of the moon that is always facing away from us on earth

not any darker than the near side

has almost no maria

manned missions to the moon

are more expensive and can’t go to all the places that robots can go to

tides per day

each day has 2 high tides and 2 low tides

high tide

when the water level at the coast is higher than normal

low tide

when the water level at the coast is lower than normal

how long tides are separated by

6 hours

tidal force

a difference in gravitation pull from 1 side of a celestial object to another

bulge

the squeezing of the earth and moon as a result of tidal forces

spring tide

when the tidal force from the moon and sun line up and enhance one another.

extra high high tide and low low tide (big change in water level)

neap tide

when the tidal force from the moon and sun don’t line up and cancel each other out.

low high tide and high low tide (little change in water level)

proxigean tide

when a spring tide occurs while the moon is close in it’s elliptical orbit.

MAXIMUM TIDES

solar eclipse

the earth passes into the shadow of the moon, blocking the sun from our view

totality is only visible by a small area on earth

lunar eclipse

the moon passes into the shadow of the earth, blocking light from reaching the moon

visible by everyone on earth

totality

the darkest part of the shadow of an eclipse. For a solar eclipse, it is small and moves across the earth

only time it’s safe to take off your eclipse glasses

how many days is the orbit of the moon

27 days

corona

the layer of the sun that is visible during a total solar eclipse

photosphere

the layer of the sun that is blocked during a total solar eclipse

who can see a lunar eclipse

everyone on earth facing the moon

who can see a total solar eclipse

only people in the path of the moon’s shadow

eye protection

is required during a solar eclipse

don’t stare at the sun

new moon

phase of the moon where the we only see the dark side

occurs during a solar eclipse

waxing

growing or getting larger

waning

means getting smaller

gibbous

means rounded

refers to a shape larger than a crescent

quarter moons

half moons

quarter refers to completing the moon completing a quarter of its rotation/orbit

full moon

phase of the moon where we only see the bright side

occurs during a lunar eclipse

new moon and full moon

phases of the moon that cause spring tides

first quarter and third quarter

the phases of the moon that cause neap tides