Download 3.4, 3.5, 3.6 Notes

3.4, 3.5, 3.6
Terrestrial &
Gas Giant
Planets
Ms. Grant
Remember the lesson goals!
1. What is known about the terrestrial
planets?
2. What is known about the gas giant planets?
3.4 TERRESTRIAL PLANETS
Unit 3 Lesson 4 The Terrestrial Planets
Extreme to the Core
What are the terrestrial planets?
• The terrestrial planets are the four small,
dense, rocky planets that orbit closest to the sun.
 In order by distance from the sun, these planets
are Mercury, Venus, Earth, and Mars.
The terrestrial planets have similar compositions
and consist of an outer crust, a central core, and a
mantle that lies between the crust and core.
Unit 3 Lesson 4 The Terrestrial Planets
 On Mars there is a greater range of temperatures
as compared to Earth. This is because of the thin
atmosphere on Mars.
• One astronomical unit is the average distance
between the sun and Earth, or approximately
150 million km.
 Earth and Venus have diameters that are nearly
equal in size.
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Unit 3 Lesson 4 The Terrestrial Planets
• Earth has prograde rotation, which means that it
rotates counterclockwise about its axis as seen
from above its north pole.
• Venus has retrograde rotation, which means that
it rotates clockwise about its axis as seen from
above its north pole.
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Unit 3 Lesson 4 The Terrestrial Planets
• It takes more time for Venus to rotate once about
its axis than it takes for the planet to revolve once
around the sun.
• The surface of Venus is covered with thousands of
volcanoes.
• Venus’s surface also has craters.
 On Venus a day is longer than a year! It also has
the densest atmospheres of the terrestrial
planets.
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Unit 3 Lesson 4 The Terrestrial Planets
• Earth is the only planet that can support life.
• Earth has liquid water, an energy source, an
atmosphere that contains oxygen, and a number
of ecosystems for different organisms to inhabit.
Matter is continuously cycled between the
environment and living things.
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Unit 3 Lesson 4 The Terrestrial Planets
• Earth is the only terrestrial planet whose surface
is divided into tectonic plates.
• Movement of these plates causes the continents
to change positions over long periods of time.
• Tectonic plate motion, together with weathering
and erosion, has erased most surface features
older than 500 million years.
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Unit 3 Lesson 4 The Terrestrial Planets
The moon rotates about its axis in the same time
it orbits Earth. Therefore, it keeps the same side
facing Earth.
• The lunar day is a little more than 27 Earth days.
• The moon’s surface temperature can reach 127 °C
in the daytime, and it can fall to –173 °C at night.
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3.5 GAS GIANTS
Unit 3 Lesson 5 The Gas Giant Planets
A Giant Among Giants!
What is a gas giant planet?
 Jupiter, Saturn, Uranus, and Neptune are the gas
giant planets.
 Gas giants have deep, massive gas
atmospheres, which are made up mostly of
hydrogen and helium. They have no surface to
stand on.
The gas giant planets are large and cold.
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Unit 3 Lesson 5 The Gas Giant Planets
Jupiter is the largest planet in the solar system.
• Jupiter’s mass is twice that of the other seven
planets combined. It has the highest surface
gravity in the solar system.
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 The center of Jupiter is extremely hot.
• Although all of the gas giant planets rotate
rapidly, Jupiter rotates fastest of all. Its period
of rotation is just under 10 hours.
 Jupiter has a much greater atmospheric
pressure than Earth does. Due to this reason
spacecrafts have not been sent with Jupiter to
explore.
Unit 3 Lesson 5 The Gas Giant Planets
• Saturn is the second-largest gas giant planet and
is made mostly of hydrogen and helium.
• Saturn’s average density is less than that of water.
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Unit 3 Lesson 5 The Gas Giant Planets
• Saturn’s most spectacular feature is a planetary
ring system that circles the planet’s equator.
• A planetary ring system is a disk of material
that circles a planet and consists of orbiting
particles.
Saturn’s ring system has many individual rings
that form complex bands. Between bands are
gaps that may be occupied by moons.
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Unit 3 Lesson 5 The Gas Giant Planets
• The atmosphere of Uranus is composed mostly of
hydrogen and helium. It also contains methane.
• The methane absorbs red light, which gives the
planet a blue-green color.
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Unit 3 Lesson 5 The Gas Giant Planets
How is Uranus unique?
• For 21 years, the north pole faces the sun and the
south pole is in darkness.
• After another 21 years, the poles are reversed.
The south pole faces the sun and the north pole is
in darkness for 21 years.
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Unit 3 Lesson 5 The Gas Giant Planets
How is Uranus unique?
• Every place on Uranus has winter periods of
constant darkness and summer periods of
constant daylight.
• During spring and fall, Uranus has periods of both
daytime and nighttime, just like on Earth.
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Unit 3 Lesson 5 The Gas Giant Planets
Neptune is the most distant planet from the sun.
• Sunlight on Neptune is 900 times fainter than
sunlight on Earth.
• High noon on Neptune may look like twilight on
Earth.
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Unit 3 Lesson 5 The Gas Giant Planets
• Neptune is almost the same size as Uranus.
• Like Uranus, Neptune has an atmosphere
composed of hydrogen and helium, with some
methane.
• Neptune’s bluish color is caused by the absorption
of red light by methane.
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Gas giants have more moons than Earth
because they are more massive than Earth
and thus have greater gravitational forces,
so they could attract more objects.
Unit 3 Lesson 6 Small Bodies in the Solar System
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Unit 3 Lesson 6 Small Bodies in the Solar System
Bigger Is not better
Where are small bodies in the solar
system?
• Scientists estimate that there are up to a trillion
small bodies in the solar system. They lack
atmospheres and have weak surface gravity.
• The largest of the small bodies, the dwarf
planets, are found in regions known as the
asteroid belt and Kuiper belt.
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Unit 3 Lesson 6 Small Bodies in the Solar System
Where are small bodies in the solar
system?
 The Kuiper belt is located beyond the orbit of
Neptune. It contains Kuiper belt objects and
comets.
• Comets are also located in the Oort cloud, which
is a region that surrounds the solar system and
extends almost halfway to the nearest star.
• Two other types of small bodies, asteroids and
meteoroids, are located mostly between the orbits
of Venus and Neptune.
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Unit 3 Lesson 6 Small Bodies in the Solar System
What are dwarf planets?
• A dwarf planet is a celestial body that orbits the
sun and is round because of its own gravity.
• A dwarf planet does not have the mass to have
cleared other bodies out of its orbit around the
sun.
• Five dwarf planets have been identified: Ceres,
Pluto, Eris, Haumea, and Makemake.
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Unit 3 Lesson 6 Small Bodies in the Solar System
What are Kuiper Belt objects?
 A Kuiper belt object (KBO) is any of the minor
bodies in the Kuiper belt. They are made of
methane ice, ammonia ice, and water ice. Most
Kuiper Belt objects have similar compositions to
comets.
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Unit 3 Lesson 6 Small Bodies in the Solar System
What do we know about comets?
• A comet is a small body of ice, rock, and dust
that follows a highly elliptical orbit around the
sun.
• All comets have a nucleus that is composed of ice
and rock.
• If a comet approaches the sun, solar radiation and
heating cause the comet’s ice to change to gas.
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Unit 3 Lesson 6 Small Bodies in the Solar System
What do we know about comets?
• A coma is a spherical cloud of gas and dust that
comes off the nucleus.
• The ion tail of a comet is gas that has been
ionized by the sun. This ion tail always points
away from the sun.
• A second tail made of dust and gas curves
backward along the comet’s orbit. This dust tail
can be millions kilometers long.
 If a comet is close to the sun, it could travel at a
speed of 445 km/s.
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Unit 3 Lesson 6 Small Bodies in the Solar System
What do we know about comets?
 The Oort cloud is a spherical region that
surrounds the solar system.
• Comets can form in the Oort cloud when two
objects collide, or when the gravity of a nearby
star sends an object into the inner solar system.
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Unit 3 Lesson 6 Small Bodies in the Solar System
On the Rocks
What do we know about asteroids?
 An asteroid is a small, irregularly shaped, rocky
object that orbits the sun.
 Most asteroids are located in the asteroid belt
between the orbits of Mars and Jupiter.
• The asteroid belt contains hundreds of thousands
of asteroids, called main-belt asteroids.
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Unit 3 Lesson 6 Small Bodies in the Solar System
What do we know about asteroids?
 The composition of asteroids varies.
Hydrocarbons are materials that are found in
asteroids.
• Some are rich in carbon.
• Others are rocky, with cores of iron and nickel.
• Some have a rocky core surrounded largely by
ice.
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Unit 3 Lesson 6 Small Bodies in the Solar System
What do we know about asteroids?
• Some asteroids appear to be piles of rock loosely
held together.
• Others contain economic minerals such as gold,
iron, nickel, cobalt, and platinum.
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Unit 3 Lesson 6 Small Bodies in the Solar System
Burned Out
What do we know about meteoroids,
meteors, and meteorites?
 A sand grain- to boulder-sized rocky body that
travels through space is a meteoroid.
 A bright streak of light that results when a
meteoroid burns up in Earth’s atmosphere is
called a meteor.
 A meteorite is a meteoroid that reaches Earth’s
surface without burning up.
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Unit 3 Lesson 6 Small Bodies in the Solar System
What do we know about meteoroids,
meteors, and meteorites?
 Meteoroids that burn up in the atmosphere that
are close enough to see are often referred to as
shooting stars.
• Meteoroids come from the asteroid belt, Mars, the
moon, and comets.
• Most meteoroids that enter Earth’s atmosphere do
not reach Earth’s surface. Many explode in the
upper atmosphere; others skip back into space.
• Large meteoroids that enter Earth’s lower
atmosphere or strike Earth’s surface can be
destructive.
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