Download The Planets

Prentice Hall
EARTH SCIENCE
Tarbuck

Lutgens
STARTER
1. Earth’s atmosphere is mostly made of
a. Water vapor
b. carbon dioxide
c. nitrogen
2. It takes Earth about _______ to rotate once.
a. 1 year
b. 24 hours
c. 30 days
3. Convection currents can occur in
a. solids only
c. gases only
b. liquids only
d. liquids, gases, and solids
4. True or False: In a convection current, the warmer,
less dense fluid rises.
5. Convection currents in Earth’s atmosphere are
caused by
a. solar energy
c. gravity
b. heat from the Earths interior
d. plate movements
• Key Concepts
• How do the terrestrial planets differ from
Jovian planets?
• How did the solar system form?
• Vocabulary
• Terrestrial Planet, Jovian Planet, nebula,
planetesimal
23.1 The Solar System
The Planets: An Overview
 The terrestrial planets are planets that are
small and rocky—Mercury, Venus, Earth,
and Mars.
 The Jovian planets are the huge gas
giants—Jupiter, Saturn, Uranus, and
Neptune.
 Pluto does not fit into either the Jovian or
the terrestrial category.
Orbits of the Planets
23.1 The Solar System
The Planets: An Overview
 Size is the most obvious difference
between the terrestrial and Jovian planets.
 Density, chemical makeup, and rate of
rotation are other ways in which the two
groups of planets differ.
 Size is the most obvious difference between the terrestrial and the
Jovian planets.
 The diameter of the largest terrestrial planet, Earth, is only onequarter the diameter of the smallest Jovian planet, Neptune.
 The Jovian planets are often called giants. (also called the
outer planets).
 The terrestrial planets are closer to the sun and are called the
inner planets.
 Density, chemical makeup, and rate of rotation are other ways in
which the two groups of planets differ.
 The densities of the terrestrial planets average about five times
the density of water.
 The Jovian planets, however, have densities that average only
1.5 times the density of water.
 Saturn would float if placed in a large enough water tank.
 The different chemical compositions of the planets are largely
responsible for these density differences.
Planetary Data
23.1 The Solar System
The Planets: An Overview
 The Interiors of the Planets
• The substances that make up the planets are
divided into three groups: gases, rocks, and ices.
 The Atmosphere of the Planets
• The Jovian planets have very thick atmospheres
of hydrogen, helium, methane, and ammonia.
• By contrast, the terrestrial planets, including
Earth, have meager atmospheres at best.
 The Interior of the Planets
 The planets are shown to scale in Figure 2.
 The substances that make up the planets are
divided into three groups: gases, rocks, and ices.
 The gases—hydrogen and helium—are those with melting
points near absolute zero (−273°C or 0 kelvin).
 The rocks are mainly silicate minerals and metallic iron,
which have melting points above 700°C.
 The ices include ammonia (NH3), methane (CH4), carbon
dioxide (CO2), and water (H2O). They have intermediate
melting points. For example, H2O has a melting point of
0°C.
 The Atmospheres of the Planets
 The Jovian planets have very thick atmospheres of hydrogen,
helium, methane, and ammonia.
 The terrestrial planets, including Earth, have meager
atmospheres at best.
 A planet’s ability to retain an atmosphere depends on its mass
and temperature.
 Simply stated, a gas molecule can escape from a planet if it
reaches a speed known as the escape velocity.
 A comparatively warm body with a small surface gravity, such
as our moon, cannot hold even heavy gases.
 In contrast, the Jovian planets have much greater surface
gravities so, it is more difficult for gases to escape from their
gravitational pulls.
 The molecular motion of a gas depends upon temperature, at
low temperatures even the lightest gases are unlikely to
acquire the speed needed to escape.
Scale of the Planets
Figure 2 The
planets are drawn
to scale.
Interpreting
Diagrams How do
the sizes of the
terrestrial planets
compare with the
sizes of the Jovian
planets?
NOTEBOOK ASSIGNMENT
• Using Figure 1 & 2 on page 644 & 646 answer
the following questions:
– Which planet is closest to the sun?
– The asteroid belt is found between which two
planets?
– Which planet is the smallest? Largest?
– How does the size of the largest planet compare to
the size of the sun?
23.1 The Solar System
Formation of the Solar System
 Nebular Theory
• A nebula is a cloud of gas and/or dust in space.
• According to the nebular theory, the sun and
planets formed from a rotating disk of dust and
gases.
NOTEBOOK ASSIGNMENT
• Complete the Reading Strategy.
23.1 The Solar System
Formation of the Solar System
 Planetesimals
• Planetesimals are small, irregularly shaped
bodies formed by colliding matter.
Formation of the Universe
Figure 3 Formation of the Universe A According to the nebular theory,
the solar system formed from a rotating cloud of dust and gas. B The
sun formed at the center of the rotating disk. C Planetesimals collided,
eventually gaining enough mass to be planets.
Planetary Composition, Distance
from the Sun, and Melting Point
Figure 4 The terrestrial planets formed mainly from silicate
minerals and metallic iron that have high melting points. The
Jovian planets formed from large quantities of gases and ices.
Classwork
• Create a chart to compare and contrast the
characteristics of the Terrestrial planets and the
Jovian planets.
• Complete the Section Assessment ( 1 thru 7)
using complete sentences
Characteristics Jovian Planets
Atmosphere
Distance form
one planet to
the next
Density
Composition
Rotation Rate
Diameter
Terrestrial
Planets
STARTER: 23.1 Review
1. What is responsible for the density
differences between the terrestrial and
Jovian planets?
2. What is escape velocity?
3. What is a nebula?
4. What is the theory for the formation of the
solar system?
5. What is a planetesimal?
•23.2 The Terrestrial Planets
• Key Concepts
• What are the distinguishing characteristics of
each terrestrial planet?
• Vocabulary
• none
23.2 The Terrestrial Planets
Mercury: The Innermost Planet
 Mercury is the innermost and second
smallest planet; it is hardly larger than
Earth’s moon.
 Surface Features
• Mercury has cratered highlands, much like the
moon, and vast smooth terrains that resemble
maria.
 Surface Temperatures
• Mercury has the greatest temperature extremes
of any planet.
Mercury’s Surface
23.2 The Terrestrial Planets
Venus: The Veiled Planet
 Surface Temperatures
• The surface temperature of Venus reaches
475oC, and its atmosphere is 97 percent
carbon dioxide.
23.2 The Terrestrial Planets
Venus: The Veiled Planet
 Venus is similar to Earth in size, density,
mass, and location in the solar system.
Thus, it has been referred to as “Earth’s
twin.”
 Surface Features
• Venus is covered in thick clouds that visible light
cannot penetrate.
• About 80 percent of Venus’s surface consists of
plains covered by volcanic flow.
Venus
23.2 The Terrestrial Planets
Mars: The Red Planet
 The Martian Atmosphere
• The Martian atmosphere has only 1 percent of
the density of Earth’s.
• Although the atmosphere of Mars is very thin,
extensive dust storms occur and may cause the
color changes observed from Earth.
 Surface Features
• Most Martian surface features are old by Earth
standards. The highly cratered southern
hemisphere is probably 3.5 billion to 4.5 billion
years old.
Mars
23.2 The Terrestrial Planets
Mars: The Red Planet
 Water on Mars
• Some areas of Mars exhibit drainage patterns
similar to those created by streams on Earth.
• Images from the Mars Global Surveyor indicate
that groundwater has recently migrated to the
surface.
Water on Mars
Classwork
• Compare and contrast Venus and Earth. (You need at
least 5 similarities and at least 5 contrasts for each planet.)
• True/False Questions. If it is false, make it true.
–
–
–
–
Mar’s polar ice caps are made mostly of water
There are active volcanoes on Mars.
Mars often has dust storms with hurricane force winds
Mars have canyons that are much larger than Earth’s Grand
Canyon.
– There is evidence that liquid water once flowed on mars.
– Liquid water currently flows on the Martian surface.
• Complete the Section Assessment (1 thru 6 ) using
complete sentences.
• Turn in the above assignment and begin on the sketches.
• Make a colored sketch of each terrestrial planet. List each
planet’s characteristics next to their sketch.
POP QUIZ!!!
1. The most obvious difference between the terrestrial and Jovian
Plant is_______.
a. Orbital Velocity
b. Color
c. Length of day
d. size
2. What is the smallest Planet?
a. Earth
b. Mars
c. Jupiter
d. Pluto
3.Which planet shows evidence of water erosion?
4.Name the terrestrial planets
5.____ is the planet that cannot be classified as neither terrestrial or
a Jovian Planet.
23.2 Mini-Quiz
1. How does Mercury’s period of rotation compare
with Earth’s?
2. What did we learn about Venus from the
Magellan spacecraft?
3. Describe the composition of Venus’s
atmosphere?
4. What did we learn about Mars from the rovers
Spirit and Opportunity?
5. What did we learn from Mars Global Surveyor?
Starter
• What are your plans for this
weekend? Its Valentines!
23.3 The Outer Planets
• Key Concepts
• What characteristics distinguish each outer
planet?
• Vocabulary
• none
23.3 The Outer Planets
Jupiter: Giant Among Planets
 Jupiter has a mass that is 2 1/2 times
greater than the mass of all the other
planets and moons combined.
 Structure of Jupiter
• Jupiter’s hydrogen-helium atmosphere also
contains small amounts of methane, ammonia,
water, and sulfur compounds.
Jupiter and the Great Red Spot
23.3 The Outer Planets
Jupiter: Giant Among Planets
 Jupiter’s Moons
• Jupiter’s satellite system, including the 28 moons
discovered so far, resembles a miniature solar
system.
 Jupiter’s Rings
• Jupiter’s ring system was one of the most
unexpected discoveries made by Voyager 1.
Jupiter’s Largest Moons
23.3 The Outer Planets
Saturn: The Elegant Planet
 The most prominent feature of Saturn is its
system of rings.
 Features of Saturn
• Saturn’s atmosphere is very active, with winds
roaring at up to 1500 kilometers per hour.
• Large cyclonic “storms” similar to Jupiter’s Great
Red Spot, although smaller, occur in Saturn’s
atmosphere.
Cassini Approaching Saturn
23.3 The Outer Planets
Saturn: The Elegant Planet
 Saturn’s Rings
• Until the discovery that Jupiter, Uranus, and
Neptune have ring systems, this phenomenon
was thought to be unique to Saturn.
• Most rings fall into one of two categories based
on particle density.
 Saturn’s Moons
• Saturn’s satellite system consists of 31 moons.
• Titan is the largest moon, and it is bigger than
Mercury.
Saturn’s Rings
23.3 The Outer Planets
Uranus: The Sideways Planet
 Instead of being generally perpendicular to
the plane of its orbit like the other planets,
Uranus’s axis of rotation lies nearly parallel
with the plane of its orbit.
Uranus
23.3 The Outer Planets
Neptune: The Windy Planet
 Winds exceeding 1000 kilometers per hour
encircle Neptune, making it one of the
windiest places in the solar system.
Neptune
23.3 The Outer Planets
Pluto: Planet X
 Pluto’s orbit is highly eccentric, causing it
to occasionally travel inside the orbit of
Neptune, where it resided from 1979
through February 1999.
Classwork
• Using Figure 15 on page 656 answer the
following questions:
–
–
–
–
How are rings A and B different from ring C?
What do you think is the cause of this difference?
How are the outer rings different from the inner rings?
How is ring E different from the other rings?
• Make a colored sketch of each outer
planet. List each planet’s characteristics
next to their sketch. Put your sketches in
order (Mercury out to Pluto).
• Complete the Section Assessment ( 1 thru
6) using complete sentences.
23.3 Mini-Quiz
1. What is the largest planet?
2. Name the three volcanic members of the
solar system family.
3. How many moons of Saturn have been
discovered thus far?
4. What is unique about Uranus’s axis of
rotation?
5. How long does it take Charon to orbit
Pluto?
23.4 Minor Members of the
Solar System
• Key Concepts
• Where are most asteroids located?
• What is the structure of a comet?
• What is the origin of most meteoroids?
• Vocabulary
• Asteroid, comet, coma, meteoroid, meteor,
meteorite
Starter
• Complete the vocab for sec. 23.4
23.4 Minor Members of the Solar System
Asteroids: Microplanets
 An asteroid is a small, rocky body whose
diameter can range from a few hundred
kilometers to less than a kilometer.
 Most asteroids lie between the orbits of
Mars and Jupiter. They have orbital periods
of three to six years.
Irregular Orbits of Asteroids
23.4 Minor Members of the Solar System
Comets
 Comets are small bodies made of rocky
and metallic pieces held together by frozen
gases. Comets generally revolve about the
sun in elongated orbits.
23.4 Minor Members of the Solar System
Comets
 Coma
• A coma is the fuzzy, gaseous component of a
comet’s head.
• A small glowing nucleus with a diameter of only
a few kilometers can sometimes be detected
within a coma. As comets approach the sun,
some, but not all, develop a tail that extends for
millions of kilometers.
Comet’s Tail Points Away from the Sun
23.4 Minor Members of the Solar System
Comets
 Kuiper Belt
• Like the asteroids in the inner solar system, most
Kuiper belt comets move in nearly circular orbits
that lie roughly in the same plane as the planets.
 Oort Cloud
• Comets with long orbital periods appear to be
distributed in all directions from the sun, forming
a spherical shell around the solar system called
the Oort cloud.
23.4 Minor Members of the Solar System
Comets
 Halley’s Comet
• The most famous short-period comet is Halley’s
comet. Its orbital period is 76 years.
23.4 Minor Members of the Solar System
Meteoroids
 A meteoroid is a small, solid particle that
travels through space.
 A meteor is the luminous phenomenon
observed when a meteoroid enters Earth’s
atmosphere and burns up, popularly called
a shooting star.
 A meteorite is any portion of a meteoroid
that reaches Earth’s surface.
23.4 Minor Members of the Solar System
Meteoroids
 Most meteoroids originate from any one of
the following three sources: (1)
interplanetary debris that was not
gravitationally swept up by the planets
during the formation of the solar system, (2)
material from the asteroid belt, or (3) the
solid remains of comets that once traveled
near Earth’s orbit.
Major Meteor Showers
Classwork
• Make a concept map using the vocabulary
for the section.
• Using Figure 21 on page 661 answer the
following questions:
– Where are most asteroids found?
– Are most of the asteroids near Earth found in
the asteroid belt?
– What is the shape f all of the asteroid orbits?
• Complete the Section Assessment ( 1 thru
6) using complete sentences.
23.4 review starter
1.
2.
3.
4.
What is an asteroid?
Where are most asteroids located?
What is the structure of a comet?
In which direction does the tail of a comet
point?
5. What is the origin of most meteoroids?