Transcript The Solar System

The Solar System
Models of the Solar System
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People have noticed the
stars and objects in the
sky for 1000’s of years.
There are two models of
how the universe was
thought to be structured
Geocentric Model
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Geocentric Model- Earth
is stationary while
objects in the sky move
around it.
Began with ancient
Greeks.
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Updated by Egyptian
Ptolemy (accepted for
almost 1500 years).
Heliocentric Model
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Heliocentric ModelEarth and other planets
revolve around the sun.
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Developed by Greek
astronomer Aristarchus
(not accepted at the time).
Became accepted model
in 1500’s when it was
supported by Nicolaus
Copernicus and Galileo
Galilei.
Components of the Solar System
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The planets orbit in an
elliptical pattern
(stretched oval), not a
circle.
Gravity and inertia
combine to keep the
planets in orbit around
the sun.
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Astronomical Unit(AU) equals the distance
from the Earth to the
sun(150,000,000 km)
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Pluto is 40 AU from the
sun.
The Oort Cloud is
50,000+ AU from the sun
(furthest points of the
solar system)
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1 AU=150,000,000 km
25.2 Earth & Moon System
Earth’s Moon
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Average
distance=384,000km
The moon has no
atmosphere, which
explains the great
variation in temperatures.
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Low=-180 Celsius/-310 F
High=130 Celsius/265 F
No atmosphere means
water cannot exist on the
moon (evaporation).
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The moon is a natural
satellite.
One of 96 moons in our
solar system.
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Earth has 1
1/6 the gravity on Earth
Formation of the Moon
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“Born” 4-5 billion years
ago (4.6 billion).
Formed from impact of
Mars-sized
“planetesimal” on Earth.
Debris from both objects
melted together to form
the Moon.
Surface Features
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Lunar Highlands cover
most of the moons
surface.
Mountains up to 7500
meters (25,000 ft) tall.
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Rilles- trench like valleys
Surface Features
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Maria-low flat plains
formed by ancient
lunar lava flows.
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They cover 15% of the
moons surface.
Galileo thought the
dark spots resembed
seas, hence Maria.
Dark spots on moon
Surface Features
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Craters-round depressions
in the surface caused by the
impact of high-speed
meteroids.
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Chunks of rock that move
through the solar system.
Some formed by volcanic
action inside the moon.
Up to 2500km (1,553 miles)
across.
These craters are evidence
that the moon is geologically
dead.
Phases of the Moon
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The moon does not produce
its own light.
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You see the reflected light
from the sun.
Phases-different shapes of
the moon visible from Earth.
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These are caused due to the
position of moon, sun, and
Earth.
Lunar Month-the time it
takes the moon complete a
full cycle of phases.
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29.5 days
The same side of the moon
always faces the Earth.
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Due to making one full
rotation (axis) while making
one full revolution around
Earth.
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Far side of moon has
different features-more
craters, few maria, and thick
crust.
Phases
Eclipses
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Eclipses occur when the
shadow of one body in
space, such as a planet
or moon, falls on
another.
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Only happen once in a
while due to varying
ecliptic planes.
2 types:
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Solar
Lunar
Tides
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Tides are the regular rise and
fall of the oceans water.
Tides are mainly caused by
gravitational pull
(differences) between the
moon and Earth.
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Depends on distance
High and low tides
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Typically 2 of each a day per
coast.
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Spring tide is when the
change in high/low tide is
the greatest.
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Due to the moon, sun, and
Earth being in a straight line.
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New or full moons
Neap tide is when the change
in tides is smallest.
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Moon and sun at right angles.
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1st or 3rd quarter moon.
The Inner Solar System
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The four inner planets are all relatively small and
dense, and have rocky surfaces.
The terrestrial planets are planets similar in
structure to Earth.
Mercury, Venus, Earth, and Mars are called the
terrestrial planets.
Mercury
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Mercury is the smallest of
the terrestrial planets and the
closest planet to the sun.
Mercury is a dense planet
with a very large iron core.
Mercury is geologically dead.
There is no mantle
convection within the planet
and little erosion on its
surface.
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Temperature can fluctuate
from 430 to -170 Celsius.
Venus
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Venus’s thick atmosphere
is composed mostly of
carbon dioxide, which
traps heat and raises the
planet’s temperature.
Venus’s atmosphere
contains droplets of
sulfuric acid.
Average surface
temperature 460 degrees.
Mars
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Mars is the most Earthlike of
all of the planets. The
weathering of iron rock on
its surface gives the planet a
reddish color. This is why
Mars is called the “Red
Planet.”
Olympus Mons is the largest
volcano in the solar system.
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3 times larger than Mt. everest.
Cleveland to D.C wide at its
base.
Asteroids
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Beyond Mars is a region
of small, rocky bodies
called asteroids that orbit
the sun.
This region is referred as
the asteroid belt
Scientist now hypothesize
that asteroids are
remnants of the early
solar system that never
came together to form a
planet
Outer Planets
The outer planets consist of the four gas giants. Pluto,
formerly considered a planet, was reclassified as a
dwarf planet in 2006.
 Gas giants have many moons, most of which revolve in
the same direction that the planets rotate.
 Each of the gas giants is surrounded by rings. A ring is
a disk made of many small particles of rock and ice in
orbit around a planet.
 Rings are so close to the planet that gravitational forces
are very large, which may have prevented the ring
particles from clumping together to form moons.
Jupiter
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Jupiter is the largest and most massive planet in
our solar system.
Sometimes storms occur at the boundaries
between these brown and white bands.
The Great Red Spot is a huge storm that rotates
around its own center like a hurricane. It is
caught between two bands of winds blowing in
opposite directions.
Jupiter has 63 moons.
Giants
Saturn
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Saturn, the second largest planet in the solar
system, is best known for its rings.
The rings are made of particles of ice and ice-coated
rock.
 These particles are generally between a few
micrometers and 10 meters across, with most
particles being snowball-sized.
 The rings are about 274,000 kilometers in diameter,
yet are only tens of meters thick.
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Uranus
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A Tilted Planet
The most unusual
characteristic of Uranus is
that it lies nearly on its side.
Uranus rotates in a direction
opposite to the direction of
its revolution around the sun.
Uranus’s rings and moons
revolve about the same tilted
axis.
Neptune
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Neptune is so far from
the sun that it takes a
very long time—165
Earth years—for it to
make one revolution.
Neptune has about the
same composition and is
about the same size as
Uranus.
Dwarf Planets
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In 2006, astronomers established a new
classification for certain objects in the solar
system that share some, but not all, of the
characteristics of a planet.
Pluto, which for many years had been
considered the ninth and most distant planet in
the solar system, was reclassified as a dwarf
planet.