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51 Cards in this Set

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What was Ptolemy's Theory?
called geocentric
His theory: earth is center of the solar system
includes earth, moon, sun, 5 planets (Mercury, Venus, Mars, Jupiter and Saturn, and a sphere of stars) all revolve around the earth
geo . . .
How many years later did Copernicus make his theory?
2000 years later
What was Copernicus's theory?
and did he prove Ptolemy wrong?
Heliocentric- sun is the center of the solar system
-Moon revolves around the earth
-earth and moon revolve around the sun
-daily movement of teh sun and stars caused by rotation of the earth
How many planets are in our solar system?
there are 9 planets in our solar system
Name the planets in order from closest to the sun, to farthest from the sun.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
What are the 5 steps that formed our solar system?
-starts as a big ball of gas called a nebula
-gravity contracts the mass
-under so much pressure starts to burn
-once it starts to burn it pushes other materials away
-material cools and forms planets
What are the two forces that keep motion around the sun?
What were Kepler's 3 laws of planetary motion?
-Eliptical orbits (not circular)
-Sun is not centered in the orbit
-Closer planets travel faster around the sun than farther planets
Name the Inner Planets
Name the outer planets
Uranus,Pluto, Jupiter, Saturn, Neptune
What are so characteristics of the Inner Planets?
-Dont have rings
-Few Moons
What are some characteristics of the Outer Planets?
All of them (except for Pluto) have/are
-Many moons
Where do meteoroids come from?
They come from melting comets
What is a meteor?
Meteors are rocks in the atmosphere
What is a Meteorite?
A Meteorite is a rock that hits a planet
What is a meteoroid?
A Meteoroids is a mass of rock in space
What is a comet?
A Comet is a mass of rock and dust mixed with frozen water and gasses. also known as a “Dirty Snowball”
What is the structure of a comet?
-Nucleus- solid center of comet (frozen hasn’t thawed yet)
-Coma- gas cloud surrounding comet

trail of gasses behind comet
1. What is the tail formed from?
2. Is there always a tail?
3. Which direction does it point and why?
1. The tail is formed by solar wind
2. No there isnt always a tail, it is only present when it's close to the sun
3. It always points away from the sun, because the solar wind pushes the tail away from the sun.
What are meteor showers caused by?
Meteor showers are caused by pieces of comet
What is the distance from the sun to Earth?
150 million km
What happens to the planets as they get further away from the sun?
As they get further, the distance between planets gets longer.
What is the order of planets from largest to smallest?
Jupiter Saturn Uranus Neptune Earth Venus Mars Mercury Pluto
Which planets have rings?
Jupiter, Saturn, Uranus, Neptune
Which planets have no moons?
Mercury and Venus
Which planets have 1 moon?
Earth and Pluto
Which planets have 2 or more moons?
Mars, Jupiter, Saturn, Uranus, Neptune
Why is venus the hottest planet?
even thought it is 2nd closest to the sun, it is the hottest planet because its atmosphere acts as a blanket and keeps the heat in
Name 3 reasons why Mercury has a lot of craters
-no atmosphere (atmosphere burns up meteors)
-no water to make them erode
-mercury is close to sun
Why is Mercury's Sky Black?
Because there is no atmosphere and light cannot scatter
What is different about venus's rotation?
Venus rotates clockwise instead of counterclockwise
What causes the bands on Jupiter?
High Winds
What are the Spots on Planets?
Which was the only planet discovered by mathematic equations?
What was the only planet discovered by a telescope?
Where is Pluto located?
The Kuiper Belt
Where do comets come from?
They come from the Oort Cloud and the Kuiper Belt.
What is an asteroid?
A piece of rock similar to but smaller than a planet orbiting the sun.
Where are most asteroids found?
In the Asteroid belt between Mars and Jupiter
What are the two main differences between asteroids and meteoroids?
-Asteroids are larger than meteoroids
-Asteroids orbit the sun (Meteoroids do not)
What is the common misconseption in movies about asteroids?
That they are close together and they really aren't
Where do comets come from?
They come from the Oort Cloud and the Kuiper Belt.
What happens to the length of a planets year the farther they get from the sun? What two factors cause this?
The further they are away from the sun the longer their year is, the two things that affect this is gravity and they have a longer orbit.
In general, how does the size of the planet affect the length of its day?
Biggest Planets= shortest days
What is commonly known as a Shooting Star?
A meteor is commonly known as a shooting star.
What is the geocentric model of the universe? Who first proposed this model?
The geocentric model of the universe is where the earth is the center of the solar system, it includes the earth, moon, sun, and 5 planets (mercury, Venus, Mars, Jupiter, and Saturn). They all revolve around the earth. Ptolemy proposed this model.
Explain the view of the solar system that Copernicus developed? What is this model called?
The model of the solar system that Copernicus developed was where the sun is the center of the solar system. The moon revolves around the earth, and the earth and moon revolve around the sun, and the daily movement of the sun and stars is caused by the rotation of the earth. This is called the Heliocentric method
3. How did Copernicus explain, in his theory, why the sun, moon and stars “appear” to be going around the earth?
He explained this by saying that the daily movement of the sun and stars is caused by the rotation of the earth.
Explain how the balance between the solar wind and the pull of gravity affected where the planets are located.
When the sun burns- doesn’t pull anything in- because solar wind is pushing out and counteracts the gravity pulling in. When they counteract, they move the planets.
What are 4 discoveries that Kepler made about planetary motion?
-closer planets travel faster around the sun than farther planets
- Further away- less gravity- slower
-Aphelion- a point of orbit farthest from the sun
-Perihelion- a point of orbit closest to the sun
What is unique about pluto and neptunes orbits?
pluto is sometimes closer to the sun then neptune, instead of being the ninth planet all the time it swithces with neptune and is the eight for a period of time