Transcript Chapter 19 The Solar System

Science 9—What have we been
doing all year?
1. Scientific Ways of Knowing and
Scientific Inquiry
2. Chemistry (physical/chemical change, atoms
(protons, neutrons, and electrons),
compounds/molecules, and chemical reactions
3. Physics (energy, PE, KE, transformations of
energy, velocity (speed + direction), Newton’s
Laws, and forces*
Science 9—Will it ever end?
4th quarter—EARTH SCIENCE
Outer space—our solar system and all of its
contents (stars, planets, and their satellites)
Where did the universe come from?
Layers of the Earth (Plate Tectonics)
The Earth as a System (atmosphere, biosphere,
lithosphere, & hydrosphere)
Innovators of Science*
Chapter 19 The Solar System
Sun, Earth, and Moon
The Inner and Outer Planets
Formation of the Solar System
Imagine you went on a trip to the
moon. What would you take with
you?
Why would you choose each item? *
1. What is a planet?
Any large object that orbits the sun or another
star
There are five planets (besides Earth) that are
visible to the unaided eye
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Mercury
Venus
Mars
Jupiter
Saturn*
2. Facts about our Sun
The sun is a star—closest star to Earth
Sun is average size and intensity star
Diameter of the sun is 1.4 million km (110 times
bigger than the Earth)
Mass of the sun is 300,000 times heavier than
Earth*
3. Day and Night
Day and night occurs because of how the earth
spins on its axis.
When our part of earth is towards the sun we
see daylight
When our part of the earth is pointed AWAY from
the sun we have darkness*
4. Solar System
Includes the sun and all the objects that orbit it
Planets
Meteoroids
Asteroids
Comets
Gas
Dust*
OGT ALERT
The next question is exactly what the
state wants you to know for your OGT.
Study this information carefully! 
5. Gravity holds the solar system
together
The force of gravity between two objects
depends upon their masses and distance
between them.
The greater the masses the larger the
gravitational forces between them.
The closer two objects are to each other, the
stronger the gravitational force between them.
Concept Check
Q1 ) Is there gravity in space?
A1) Yes all objects are acting on each other
Q2) Why do astronauts have a feeling of
weightlessness if there is gravity in space?
A2) They are in free-fall with earth’s gravity
pulling on them, but their forward motion along
their orbit keeps them from getting closer to
earth. *
6. Nine Planets?
Planets can be seen because their surfaces
reflect sunlight.
Orbits of planets are directly related to their
distance from the sun
Mercury orbits the sun in 88 days
Earth orbits in 365.25 days
Pluto 248 years (sometimes crosses in front of
Neptune making it the 8th planet instead of the
9th)
7. Satellites
Object in orbit around a body that has a larger
mass
What is earth’s satellite?
The moon is the earth’s satellite because the
moon has a smaller mass.
Larger planets usually have more satellites
8. What holds satellites in place
Since mass is related to gravitational pull, it
makes sense that larger more massive planets
may have more satellites.
A few satellites have atmospheres, but most do
not.
9. Moon Phases
Appearance of different shapes of the moon.
Does the moon really change shape?
No, but the position of the earth, moon, and sun
cause us to see different shapes of the moon.
The time from one full moon to the next is 29.5
days.
10. Eclipse
Can be predicted and occur when the sun,
moon, and earth are in a straight line
Solar eclipse= moon casts a shadow onto Earth;
within this small shadow area the moon blocks
the sun
Lunar eclipse = the moon passes into the
shadow of the earth; a full moon darkens; this is
rare because of the moon’s orbit being slightly
tilted
11. Tides
Coastal areas have two high and two low tides
everyday.
Tides are mainly due to the gravitational pull of
the moon on the water
The gravitational attraction is strongest between
the side of the earth that is closest to the moon
and weakest on the side farthest from the moon.
12. Asteroids
Minor planets
3-700 km in diameter
Remember that Pluto’s diameter is only about
2300 km
13. UB 313
Confirmed February 1, 2006
14. Nebula
Large cloud of dust or gas in space.
The most accepted model for the creation of the
solar system is by way of a nebula
15. Comets
Probably composed of leftover material from
when the solar system was formed
Dust and ice made of methane, ammonia,
carbon dioxide, and water
Solar winds blow the dust to make a trail behind
the comet
16. Meteors and Meteorites
Meteors are small pieces of rock
Meteoroids are small pieces of rock that enter
earth’s atmosphere
Meteorites are small piece of rock that survive
the atmosphere and hit the ground
Most were once asteroids
Some may have come from the moon or Mars
17. Craters
Meteoroids less than 10 m across usually burn
up in the atmosphere.
Earth has been hit over 100 times by meteorites.
The impact of meteorites cause craters
Could a meteorite that was only 10-15 km wide
have caused the extinction of the dinosaurs?
This could have released as much energy as
10,000,000 hydrogen bombs