Transcript Our Galaxy and Solar System

Our Galaxy and Solar System
Our Galaxy – huge cluster of stars and
other matter
Milky Way -
Spiral Galaxy
Where is our solar system located?
In an arm on the outer edge of the Milky Way
Our Solar System
a. Formation of the sun
i.
ii.
iii.
iv.
v.
4-5 billion years ago a solar nebula
formed.
Heat from collisions and pressure
from the force of gravity caused the
center of the nebula to become
hotter and denser.
Hydrogen fusion began and our sun
was born.
99% of the matter in the solar nebula
became part of the sun
Took 10 million years to form
b. Formation of the Planets
i. Occurred at the same time the sun
was forming
ii. Small bodies of matter
(planetesimals) in the outer edges of
the solar nebula joined together to
for larger bodies called protoplanets.
iii. Protoplanets condensed into the
smaller bodies (planets) we have
today.
A. Terrestrial Planets
Inner, small, dense, rocky
Mercury, Venus, Earth, Mars
Mercury
Venus
Atmosphere of 98%
Carbon Dioxide
Causes intense
greenhouse effect
which makes the
surface to be
over 900oF
Earth
Only planet that
has water in all
3 phases
MARS
Olympus Mons – volcano the size of Nebraska on Mars
Largest in the solar system
B. Jovian Planets
Outer, large, gaseous
Jupiter, Saturn, Uranus, Neptune
Jupiter and Io, one of its moons
Io is the most volcanically active body in our solar system
Jupiter and its Great Red Spot –
continental size storm system
Saturn
Saturn in UV light
Neptune
Uranus
c. Formation of Earth
As the matter from the nebula
came together, gravity
caused the more dense
materials to flow to the
center of the planet.
» giving the
planet 3
distinct layers:
Core, Mantle,
Crust
Other objects in our Solar
System
• They all revolve around the
___________
SUN
Other objects in our Solar System
• Asteroids - Bit of rock that orbits around
the sun, range in size from hundreds of km
to mm
• It can be thought of as what was "left over"
after the Sun and all the planets were
formed
• Asteroid Belt – located between Mars and
Jupiter
• May have caused the extinction of
dinosaurs and global climate change
Comets – cosmic icebergs
• Haley’s Comet – orbits the sun every 76
years
• Next time we should see it, early 2062
Hale-Bopp Comet
• 1996/1997
• Next time – year 4530
Meteors
• Small particles pulled into our atmosphere
by gravity
• Meteors will burn up when they hit our
atmosphere due to friction.
• If they reach the Earth’s surface, they are
called meteorites
Meteorite Evidence on Earth
Most metorite
evidence on
Earth
is eroded by
weathering
Perseid and Leonid meteor
showers
• Perseid – mid August
• Orionids – October 20 and 21 Leonids –
November 17-18
• Geminids – Dec 13-14
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