Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
33 Cards in this Set
- Front
- Back
|
solar system
|
the sun and all of the bodies that orbit the sun |
|
|
heliocentric |
earth and the other planets orbit the sun |
|
|
geocentric |
earth was the center of the solar system, with the sun, moon, and the planets circling it |
|
|
parallax |
the apparent shift in the position of an object when viewed from different locations |
|
|
gravity |
the force of attraction between objects that is due to their masses and the distances between them |
|
|
orbit |
the path that a body follows as it travels around another body in space |
|
|
aphelion |
the farthest earth is away from the sun in its orbit; occurs on about july 4 |
|
|
perihelion |
the closest earth is to the sun in its orbit; occurs on about january 3 |
|
|
kepler's first law kepler's second law kepler's third law |
planetary orbits are ellipses with the sun at one focus planets move faster in their orbits when closer to the sun relates the distance of a planet from the sun to the time it takes to complete one orbit |
|
|
law of universal gravitation |
all objects in the universe attract each other through gravitational force; as the distance between two objects increases, the force of gravity decreases |
|
|
centripetal force |
the inward force that causes an object to move in a circular path |
|
|
solar nebula |
a cloud of dust and gas from which the solar system formed |
|
|
protostellar disk |
where the sun formed; from the solar nebula rotating faster and flattening out into a disk |
|
|
planetesimals |
meter sized objects, formed from dust grains colliding and growing in size, that collided to form kilometer sized objects |
|
|
protoplanetary disk |
the disk in which the planets formed |
|
|
terrestrial planets |
rocky, metallic planets that formed in the hot inner protoplanetary disk (Earth, Venus, Mars, and Mercury) |
|
|
gas giant planets |
planets with ricky or metallic cores and deep atmospheres of gas and ice that formed in the cold outer protoplanetary disk; the gravity was so strong that they captured gas and other matter as they grew (Saturn, Jupiter, Uranus, and Neptune) |
|
|
rotation |
the spinning of a planet on its axis earths rotation is counter clockwise (west to east) |
|
|
day |
the time it takes a planet to complete one full rotation; 24 hours |
|
|
revolution |
the motion of a body/planet that travels around another body in space |
|
|
year |
the amount of time it takes earth to complete a full revolution around the sun 365 1/4 days |
|
|
season |
a pattern of temperature and other weather trends; the tilt of earths axis (23.5°) and earths spherical shape play a roll in earths changing seasons |
|
|
equinox |
means "equal night"; sun shines equally in the northern and southern hemispheres fall equinox/spring equinox |
|
|
solstice |
means "sun stops"; the sunlight is at a maximum in one hemisphere and a minimum in the other hemisphere winter solstice/summer solstice |
|
|
precession |
the wobbling motion of earth as it turns on its axis; caused by the gravitational pull exerted on the earth by the moon, sun, and other planets causes earths axis to move slowly in a circle |
|
|
satellite |
a body that orbits a larger body |
|
|
moons |
natural satellites |
|
|
lunar phases |
the portion of sunlight that the moon reflects to earth changes causing the moons appearance to change |
|
|
eclipse |
an event during which one object in space casts a shadow into another |
|
|
lunar eclipse |
when the moon moves through earth's shadow |
|
|
solar eclipse |
when the moon is directly between the sun and Earth, the shadow of the moon falls on a part of the earth; the suns light is completely blocked by the moon |
|
|
umbra |
the darkest part of a shadow |
|
|
penumbra |
spreading cone of lighter shadow |
