Astronomy Flashcards
difference between earth’s rotation and revolution
rotation- spins on axis
revolution- yearly orbit around sun
how long is earth’s revolution and rotation
rotation- 24 hours/ 1 day
revolution- 365.25 days/ one year
what causes day and night
earth’s rotation- side of earth facing the sun in daytime, while other side is nighttime
what causes seasons
tilt of earth and earth’s revolution around the sun
what shape is earth’s revolution around the sun?
ellipse (oval)
when is earth closest to the sun
during winter in the northern hemisphere
what is leap year
a year when an extra day is added to the calendar in February
how often does a leap year occur? why?
every 4 years
the earth revolves around the sun every 365 days and 6 hours. our calendar is only 365 days. to make up for the missing 6 hours, we add a day to the calendar every 4 years
whats the difference between an equinox and a solstice
equinox- 2 days a year when there is equal day and night
solstice- the days during the year where there is the longest amount of sunlight and the shortest amount of sunlight
when does the equinox and solstice occur
equinox- 1st day of fall and spring
solstice- 1st day of summer and winter
what is a lunar eclipse
the sun, earth and moon are in a line and earth’s shadow falls on moon
appears to go through moon phases and turn red during totality because the sunlight traveling through earth’s atmosphere bends and reflects on the moon
can only occur during night with full moon
what is a solar eclipse
the sun, moon, and earth are in a line. the moon blocks out the sun
can only occur during day and new moon
what causes tides
the gravitation pull of the sun and moon (mostly moon)
when do tides occur
every 6 hours, 2 high tides and low tides
difference between high tides and low tides
high tide- water level rises
low tide- water level decreases
why does the moon appear to change shape?
the relative position of the sun, moon, and earth changes throughout the lunar cycle
why do we only see one side of the moon
the moon rotates and revolves at the same speed (28 days)
moon phases
new moon, waxing crescent, 1st quarter, waxing gibbous, full moon, waning gibbous, last quarter, waning crescent, new moon
what are constellations
a group of stars that form a pattern in the sky that form a special formation
why do constellations appear to change
as the earth rotates, constellations appear to move
as earth revolves around the sun, you see different constellations
some are visible all year because of their location
what is a galaxy
a large group of stars, dust, and gas held together by gravity
what galaxy do we live in
milky way-spiral
3 types of galaxies
spiral- looks like a pinwheel
elliptical- looks like a flat disc, frisbee
irregular- has no definite shape
comets, asteroids, meteoroids, meteors, and meteorites
comet- space object made of dust and rock particles mixed with frozen water, methane, and ammonia; creates a tail as it approaches the sun
asteroid- a large piece of rock or metal made up of material similar to that which forms planets, mostly found in the asteroid belt
meteoroid- a piece of rock or metal travelling in space
meteor- a meteoroid that burns up in earth’s atmosphere
meteorite- a meteoroid that strikes a moon or planet
what is an asteroid belt? where?
a collection of asteroids located between the orbits of mars and jupiter
mass, gravity, and weight
mass- the amount of matter in an object
gravity- an attractive force between objects that have mass
weight- gravity’s effect on an object’s mass
more mass=more gravity
more gravity=more weight
