Download Chapter 29 Our Solar System

Chapter 29 – Our Solar System
"The earth is the cradle of
humankind, but one cannot
live in the cradle forever."
-- Konstantin Tsiolkovsky, 1895
29.1 Overview of our
solar system
OBJECTIVES
Describe early models of our solar
system.
Examine the modern heliocentric model
of our solar system.
Relate gravity to the motions of
celestial bodies.
Early Ideas
Geocentric ,meaning “Earth Centered”
In the early 1500s, Nicholas Copernicus formulated the
heliocentric model of the solar system.
Copernicus
Nicolaus Copernicus found that
in a heliocentric model of the
solar system,
• the inner planets move faster
in their orbits than the outer
planets,
• giving the appearance from
Earth that some planets move
in a retrograde motion.
(http://imagine.gsfc.nasa.gov/Images/people/Copernicus.gif )
Retrograde Motion
Retrograde motion is the movement of a planet in an
opposing direction across the sky.
Galileo
Galileo’s discovery of Jupiter’s
moons proved that not all
celestial bodies orbit Earth;
therefore, Earth is not
necessarily the center of the
solar system.
Kepler’s First Law
Kepler’s first law demonstrates that each
planet has an elliptical orbit of unique size
and shape with the Sun at one focus.
AU
Earth’s average distance from the
Sun: 1.496 x 108 km
or 1 astronomical unit.
Planets’ Orbits
All of the planets (& former planets) and their satellites
orbit the Sun in the same direction, and all their orbits,
except Pluto's lie near the same plane.
Eccentricity
When a planet is closest to the sun in its
perihelion
orbit, it is at ____________
and when it is
aphelion
farthest from the sun, it is at _________.
Ellipses
Terms to be familiar with.
•Major axis
•Foci
•Semi-major axis
•Perihelion
•Sun
•Aphelion
Eccentricity
e=
Distance between foci
Major axis length
Kepler’s Second Law
Closer  Faster
Farther  slower
Kepler’s second law is an imaginary line between the
Sun and a planet that sweeps out equal amounts of
area in equal amounts of time.
Center of Mass
Isaac Newton determined that each planet does not orbit the Sun
but instead orbits a center of mass between it and the Sun.
29.1
Overview of our Solar System Quiz
29.2 The Terrestrial Planets
OBJECTIVES
Describe the
properties of
the
terrestrial
planets.
Compare Earth
with the other
terrestrial
planets.
Precession
The wobble of the Earth’s rotational axis is
called precession.
The Moon’s gravitational force on Earth causes
the sideways push that is responsible for
precession.
Mercury
has the largest daynight temperature
difference of all the
planets in the solar
system.
Mariner 10 image of Mercury
Venus
is the planet most
similar to Earth in
physical properties,
such as diameter,
mass, and density.
Venus - Computer Simulated
Global View Centered at 180
Degrees East Longitude
Venus
(more)
The high concentration of carbon dioxide (CO2)
in the atmosphere of Venus inhibits infrared
radiation from escaping and keeps the
surface extremely hot.
Earth
is the only known planet
in our solar system
where H2O is present
in three states, solid,
liquid & gas.
Image by Reto Stöckli (land
surface, shallow water,
clouds).
Terrestrial planets are close to the size
of Earth and have solid and rocky surfaces,
while the gas giant planets are larger, more
gaseous, and lack solid surface.
29.2 The Terrestrial Planets
Planet
Mercury
Rotation
Period &
Size
Atmosphere
&
Temperature
1407.6
Hrs,
1/3 Earthsize
Atmosphere
almost nonexistent.
Mostly O2 and
Na, Day 429◦C
to -173◦C at
night
Venus
243 days,
95% of
Earthssize
Primarily CO2
& N2,clouds
of sulfuric
acid, Average
temperature
is 464◦C
Earth
24 hrs,
Exactly
Earthsized
(wink!)
78% - N2
21% - O2
Average
temperature
is 15◦C
24 hrs 37
minutes,
½ of
Earth’s
size
Thin and
consistent wind,
composition
similar Venus’s.
Average
temperature is 60◦C
R
Mars
Surface
Features
Interior &
Magnetic
Field
Additional
Features
Craters and
plains
High-density
extensive
nickel-iron
core, molten
zone presentmagnetic field
detectable.
No moons
Smoothed by
lava flows few
impact-craters
Theorized
that it is
similar to
earth, no
data to back
this up.
No moons,
highest albedo
of any planet,
spin is
retrograde,
extreme
greenhouse
effect
Effects of
impacts erased
by erosion
Crust,mantle,
inner and
outer core,
presence of
magnetic
field.
presence of
liquid
water, mild
Plains &
volcanoes
Theorized
core of Fe &
Ni, no
magnetic
field.
2 moons, red
color due to
high Fe in
soil
1 moon,
greenhouse
effect
Atmospheric conditions of the
four terrestrial planets
Mercury
•
almost nonexistent
• mostly
oxygen and
sodium
Mercury
Venus
• thick clouds
• primarily of
carbon
dioxide and
nitrogen
• Include
sulfuric acid
Venus
Earth
Mars
• moderately
dense
• composed of
78% nitrogen
and 21%
oxygen
• thin and there
is consistent
wind.
• composition
is similar to
Venus’s
Earth
Mars
29.3 The Gas Giant Planets
OBJECTIVES
Describe the properties of the gas giant
planet.
Identify the unique nature of the object
“formerly-known-as-the-Planet-Pluto”.
29.3 The Gas Giant Planets
Planet
Jupiter
Rotation
Period &
Size
9.925 hrs,
11 X
Earth’s
size
Saturn
10 hrs 39
minutes,
almost 10
X Earth’s
size
Uranus
17.24R
hrs,
3.95 X
Earth’s
size
Neptune
16 hrs 11
minutes,
3.87 X
Earth’s
size
Atmosphere
90% - H2
10% - He,
Liquid
metallic
hydrogen
present
75% - H2
25% - He,
Liquid
metallic
hydrogen
present
Surface
Features
Interior &
Magnetic
Field
Belts are low,
Earth-sized solid
warm, darkcore of heavier
colored clouds
material, magnetic
that sink. Zones field generated by
are high, cool , electric currents
in liquid metallic
light-colored
hydrogen.
clouds that rise.
Structure similar
to Jupiter.
Earth-sized solid
core of heavier
material, magnetic
field 1000 times
stronger than
earth’s.
83% - H2
No distinct zones
15% - He
Very small solid
or belts.
2% - Methane, Structure similar
core, Strong
this gives it
the bluegreen color
to Jupiter and
Saturn.
Similar to
Uranus
Distinct zones &
belts present.
Structure similar
to Jupiter and
Saturn.
magnetic field.
Similar to
Uranus.
Additional
Features
63 moons,
accounts for 70%
of mass of our
solar system’s
planets
Prominent
feature is the
rings, 61 named
moons, second
largest in our
solar system,
least dense ,
less than that
of water
Rings present,
at least 27
moons, axis is
tipped to almost
90 degrees
(rolls around
the sun?)
Rings present,
13 moons,
blue-green
color
29.3
the object “formerly-known-as-the-
Planet-Pluto”.
Planet
Rotation
Period
Atmosphere
Pluto
6.38R
days, 17 %
of Earth’s
size
98% N2,
Methane and
traces of
CO
Surface
Features
More similar to a
moon of the gas
giants.
Interior
50% to 75%
rock mixed
with ices
Additional
Features
Largest
difference
between
Aphelion (50 AU)
and perihelion
(30 AU)
Composition
The gas giants are composed primarily of
lightweight elements, such as hydrogen,
helium & methane.
Jupiter
Saturn
Uranus
Neptune
Rapid Rotation
The rapid rotation of the largest gas giant
Jupiter, causes its clouds to flow in
alternating cloud types called belts and
zones.
Jupiter
Belts are low, warm, darkcolored clouds that sink.
Zones are high, cool ,
light-colored clouds that
rise.
Blue Color
Neptune and Uranus , the two gas giants
appear blue because of the methane in
their atmosphere.
Uranus
Neptune
Neptune
Neptune has clouds and atmospheric belts
and zones similar to those of Saturn and
Jupiter.
Neptune
Pluto’s Eccentricity
Pluto’s orbit is so eccentric that while at
perihelion, Pluto is closer to the Sun than
Neptune is.
Pluto's orbit seen from the plane of the
ecliptic, showing its high inclination
compared to the other planets
The eccentric orbit of Pluto is 50 AU from the
Sun at aphelion and almost 30 AU from the
Sun at perihelion.
Terrestrial and the Gas giant planets
Both are categories of the planets of our solar system
Terrestrial planets
• four planets close to the
Sun
• Mercury, Venus, Earth,
and Mars
• solid, rocky surfaces
• smaller
Gas giant planets
• farther from the Sun
• Jupiter, Saturn, Uranus,
and Neptune
• more gaseous
• lack a solid surface
• larger
29.2 & 29.3 Quiz (8pts)
Riddle me this .
29.4 Formation of Our
Solar System
OBJECTIVES
Describe how the
planets formed
from a disk
surrounding the
young sun.
Explore remnants of
solar system
formation.
Interstellar Cloud
Interstellar cloud, a
cloud of gas and dust
from which stars and
planets are formed.
Interstellar cloud
can condense and
become
concentrated
enough to form a
star and possibly
planets.
The dense
concentration of
gas at the center
of the solar
nebula eventually
became the Sun.
Solar Nebula Theory
Planetismals are
tiny grains of
condensed
material that
accumulate and
merge together to
form these large
bodies possibly
growing until
they reach
hundreds of
kilometers in
diameter.
Planetismals
Asteroids
Bodies of
interplanetary
debris that
orbit the Sun
with most in
the area
between Mars
and Jupiter are
called
asteroids.
Comets are small,
icy body made of
ice and rock that
has a highly
eccentric orbit
around the Sun.
The Oort cloud and
the Kuiper belt
are two cluster
of comets.
Comets
Haley 's comet seen here
in 1986. It will appear
again in 2062.
Meteor
The result when Earth
intersects a cometary orbit
is a meteor shower.
Meteor
Meteor is interplanetary
material that burns up
and becomes a bright,
glowing streak of light
in Earth’s atmosphere.
Two examples are the
Perseids (August) &
Leonid (November).
Meteorite
Is interplanetary material that enter’s Earth’s
atmosphere and collides with the ground rather
than burning up.
29.4 Quiz