Transcript Solar System - MrsAllisonMagee

Solar System
Chapter 27
Solar System
• Solar System: consists of the sun, the
planets, and all of the other bodies
that revolve around the sun.
Planets
• Planets: a celestial body that orbits the sun,
is round because of its own gravity,
and has cleared the neighborhood
around its orbital path.
Nebular Hypothesis
• Solar Nebula: a rotating cloud of gas and
dust from which the sun and
planets formed.
Formation of Planets
• Planetesimal: a small body from which a
planet originated in the early
stages of development of the
solar system.
Formation of the Planets
• Protoplanets: collide with other bodies
and become very large and
eventually condense to form
planets and moons.
• Moons: are smaller bodies that orbit the
planets.
Inner Planets
• Mercury, Venus, Earth, Mars
• Close to the sun, contain heavier
elements, solid surfaces, smaller, rockier,
and denser
Outer Planets
• Jupiter, Saturn, Uranus, Neptune
• Formed in colder regions, far from sun.
• Considered gas giants, have low density.
Terrestrial Planets
• Terrestrial Planet: one of the highly
dense planets nearest to the sun.
(Mercury, Venus, Earth, Mars)
Mercury
• Smallest planet
• Fastest orbit ~88 days
• Iron core
• First explored in 1973
by Mariner 10
• No atmosphere
Mercury's Molten Core
• Mercury’s surface is heavily cratered.
• Temperature varies greatly.
Venus
• 7,520 miles in diameter
• 67.2 million miles from the sun
• 2nd brightest object in the night
sky after the full moon
• Morning/Evening “Star”
• Has sulfur dioxide droplets in its
upper atmosphere, which form a
cloud layer that reflects the
sunlight making it really bright.
Venus
• 225 Earth-days = 1 Venus year
• 243 Earth-days = 1 Venus day
• Atmosphere almost entirely CO2
• Atmospheric pressure 1,320
pounds per square inch (about
90 times Earth’s)
• Surface temperature 465oC
Missions to Venus
• 1970’s Soviet Union: sent probes and
viewed a rocky landscape.
• 1990’s USA: sent a satellite and
discovered mountains, volcanoes, lava
plains, and sand dunes.
Earth
• Orbital Period: 365
days
• One rotation on its axis
every day.
• Earth is unique with
water being in a liquid
state.
• Moderate
Temperatures due to
atmosphere.
• Oxygen in atmosphere
because of plants.
Luna = Our One Large Moon
Mars
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Orbital Period is 687 days.
Rotates on its axis every 24hr and 37 minutes
Almost same axis tilt as Earth, very similar seasons.
Volcanoes, Valleys, No moving tectonic plates
Mars
• Pressure and
Temperature of Mar’s
atmosphere are too low
for water to exist as a
liquid, yet we believe it
did exist at one time.
• Temperatures vary from
20C near poles to -130C
at the equator.
Mar’s Rover - Curiosity
• Video – “7 minutes of Terror”
• Nasa Website
The Outer Planets
• Jupiter, Saturn, Uranus, Neptune
• The outer planets are separated from the
inner planets by a ring of debris called the
asteroid belt.
The Outer Planets
• Jupiter, Saturn, Uranus, Neptune
• Gas Giants: a planet that has a deep
massive atmosphere made mostly of gas.
The Outer Planets
• Their thick atmosphere is mostly made of hydrogen
and helium gases, forming a cloud layer.
• All four gas giants have ring systems that are made
of dust and icy debris that orbit the planets.
Jupiter
• Largest Planet
• Its mass is more than 300
times that of Earth.
• Orbital period – 12 years
• Rotates on axis the fastest
(9 hr 50 min)
• Jupiter has 60 moons
• Thin rings
Jupiter’s Moon Io
Jupiter's moon Europa
Jupiter’s Coloring
• The coloring suggests the
presence of organic
molecules mixed with
ammonia, methane, and
water vapor.
• Jupiter’s rapid rotation
causes these gases to swirl
around to form bands.
• Average Temperature -160C
• Lightening Storms and
Thunderstorms are common.
Great Red Spot
• The Great Red Spot is
an ongoing massive
hurricane storm that is
about twice the diameter
of Earth.
• This storm has been
raging for several
hundred years.
Saturn
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•
•
•
Orbital Period of 29.5 years.
47 Moons
Least Dense Planet
Most complex/Extensive
system of rings
• Rotates on axis 10hr30 min
• Saturn bulges at its equator
and flattens at its poles.
Saturn's moon Enceladus
Uranus
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•
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•
•
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24 Moons
11 Thin Rings
Orbital Period 84 years
Unusual Orientation
Rotates every 17 hr
Blue-Green color suggests
that the atmosphere contains
amounts of methane.
Uranus' moon - Miranda
Neptune
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•
•
•
•
•
Orbital Period is 164 years
Rotates about every 16hr
13 Moons
6 Rings
Roman God of the Sea
White Clouds - frozen
methane.
• Strongest Winds
• The Great Dark Spot
Neptune's moon - Triton
Pluto
• Dwarf Planet
• Orbits in an unusual
elongated and tilted
ellipse.
• Smaller than Earth’s
Moon
• Made of frozen
methane, rock, and ice.
Kuiper Belt
• Kuiper Belt: a region of the solar system
that starts just beyond the orbit of Neptune
and that contains dwarf planets and other
small bodies made mostly of ice.
Other Solar System Bodies
Early Models of the Solar System
• Ptolemy’s Model: Earth is centered and
the planets move around Earth
• Copernicus’s Model: the planets are
moving at different speeds around the sun.
Kepler’s Laws of Planetary Motion
• Eccentricity: the degree of elongation of
an elliptical orbit.
• Orbital Period: the time required for a
body to complete a single orbit.
• Inertia: the tendency of an object to resist
being moved or changed until an outside
force acts on the object.
Formation of Solid Earth
• Differentiation: occurred on Earth when
denser materials sank to its center and
less dense materials were forced to the
outer layers.
• (3 distinct layers: core, mantle, crust)
Formation of Earth’s Atmosphere
• Earth’s early atmosphere
formed as volcanic eruptions
released nitrogen, water
vapor, ammonia, methane,
and carbon dioxide.
• Present Earth’s atmosphere
is 78% nitrogen, 21% oxygen,
and 1% other gases.
Formation of Earth’s Oceans
• Earth’s water came from space as ice
bodies (comets) collided with Earth. As
Earth cooled the water vapor condensed
and formed rain.
• Over millions of years the water cycle
occurred causing our oceans to become
salty.
Group Planet Assignment
Each Group Will:
• Research their assigned planet/objects
– Include
• Size and distance data
• Composition
• Human exploration efforts
• Human colonization possibilities
• Prepare a poster with a drawing and important information
• Prepare a 3 – 5 minute presentation for the class. You
may include web/electronic resources if prepared in
advance.