Planet Formation and the solar system REVIEW
The raw materials to form planets come most directly from what source?
Interstellar dust and gas clouds from an exploded star. These clouds are called nebula
What are the smallest particles that begin to form planets?
DUST AND GAS
What causes these particles to combine?
GRAVITY
When the dust particles combine, what are they called?
Planetessimals
Planetesimals
What is an example of a very large planetesimal?
A comet
When enough planetesimals collide to have enough gravity to cause the body to become round, what is that body then called?
A Proto-planet
When enough proto-planets collide, what do they become?
A PLANET
What caused the Earth to be a ball of molten (melted) rock when it formed?
Collisions of the proto-planets caused it to totally melt
Where did our atmosphere come from?
Gasses given off by volcanoes
Where did the oceans come from?
Water vapor in the atmosphere condensed when the Earth cooled and it rained, and rained
Where did our oxygen come from?
Plants evolved in the oceans and used the carbon dioxide from the atmosphere to make oxygen.
What is accretion?
The buildup of something like a planet from accumulating many small pieces.
Name the smallest part
Dust and gas Planetessimals Proto-planets Planet
Why did the planets stop growing?
What protects Earth from solar wind?
The Earths Magnetic field or Magnetosphere
What does solar wind produce in our atmosphere?
Aurora Borealis
Why doesn’t Mars have much atmosphere or water?
It lost it’s magnetosphere and the solar wind blew them away
What is the closest planet to the sun?
Mercury
Why is mercury so hot in the daytime and -150 at night?
It has no atmosphere to keep the heat in at night, so the heat radiates out into space.
Why doesn’t Mercury have an atmosphere?
The solar wind blew it away
What is the hottest planet?
VENUS
Why is Venus hotter than Mercury?
It’s thick Carbon Dioxide atmosphere is very good at letting the sun’s heat in but not letting it back out.
Why are the day and night temperatures the same on Venus?
It’s thick Carbon Dioxide atmosphere is very good at letting the sun’s heat in but not letting it back out even at night.
Why are conditions on Earth perfect for life?
In middle of Goldilocks Zone The atmosphere holds just the right amount of the sun’s heat. Earth’s magnetic field protects it from the solar wind
Why is it colder than it should be on Mars?
Mars has such a thin atmosphere that it can’t trap the sun’s heat.
What happened to Mars’ atmosphere?
It lost it’s magnetic field and the solar wind blew the most of the atmosphere away
What 4 planets are terrestrial, or rocky, planets?
MercuryMary VenusVery EarthEarly MarsMade
What 4 planets are Gas Giants?
JupiterJune SaturnSome UranusUnusually NeptuneNice Pies
Why do we only find gas giants far from the sun?
It is so warm close to the sun that hydrogen and helium molecules move faster than the inner planets escape velocity NEXT
It is COLD near the outer planets, so helium and hydrogen molecules move too slowly to escape the outer planets gravity
Why are the outer planets so LARGE?
Hydrogen and helium are the most common elements in the universe, so there was a lot of it there for the giants to sweep up.
What is the largest planet?
Jupiter
What Planet has such low density that it would float in water?
Saturn
Why does Saturn have a yellow color?
It has some sulfur in its atmosphere that gives it a yellow color
Why are Uranus and Neptune blue?
There is methane in their atmospheres that causes the blue color
Why is Neptune the coldest planet?
At 30 times farther from the sun than Earth, it gets very little heat from the sun
Which of the gas giants have rings?
ALL of them have rings, but only Saturn’s rings are visible from Earth.