Transcript Our Solar System

Astronomy
Notes
Notes Created by Harris Middle
School with graphics cited.
Part 1
Image From: http://www.astronomy-pictures.net/spiral_galaxy.jpg;
Scale
model
! !
Scale
model
Size of the planets
compared to the Sun
Scale model !
The Inner Planets and our moon
(The Terrestrial Planets)
Scale model !
The Outer Planets
compared to the Inner Planets
(The Gas Giants)
Click: http://www.youtube.com/watch?v=HEheh1BH34Q
1. Universe- contains everything that may or may
not exist in space
2. Galaxy- system of stars held together by gravity.
3 types: Spiral, Elliptical, and Irregular. Ex: Milky
Way
3. Nebula= interstellar cloud of gas
4. Star- self luminous sphere of gas. Ex: sun
5. Planet- celestial object moving in orbit around
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Stars
• An object made of gas that gives off energy
– mainly hydrogen
– helium
The Sun
•
•
•
•
medium in size & life span compared to other stars
primary energy source for all processes on Earth
much closer to Earth than any other star!
about 4 ½ billion years old
Black Dwarf
Nebula
1. Large
cloud of
gas & dust
where
stars form.
2. Gravity pulls
4. Outer layers
5. Collapses
material into a
come off
sphere that
to just its
3. Expands
becomes
core
dense, hot
Explodes!
& ignites.
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Hertzsprung-Russell Diagram
• Chart to classify luminosity & temperature of stars
• Luminosity- how BRIGHT or DIM star is. (y-axis)
• Temperature- higher (hotter) temperatures on
left, and lower (cooler) temperatures are on
right. (x-axis)
Temperature and Color
H-R Diagram
H-R Diagram: Shows the relationship between
color, temperature, magnitude & size of stars.
• Color = temperature
• Luminosity = how bright
• Our Sun is a main sequence star.
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H-R Diagram
H-R Diagram
copy and label in journal as (HOT,COOL) (BRIGHT, DIM)
Luminosity
______, _______
______, _______
SUN
______, _______
temperature
______, _______
H-R Diagram ANSWERS
copy and label in journal as (HOT,COOL) (BRIGHT, DIM)
Luminosity
BRIGHT HOT
______, _______
SUN
______, _______
temperature
______, _______
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Galaxy
• A large grouping of stars, dust/gas in space
• 3 types
1. Spiral – bulge in center & distinctive spiral arms
•
•
2.
3.
1
Example: Our galaxy, The Milky Way
Our solar system is located within an arm
Elliptical – spherical or elongated
Irregular
2
3
Our Solar System
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Terrestrial Planet: a rocky, INNER planet
Mercury
• closest to the sun
• no atmosphere
• full of craters
• very hot during day; freezing cold at night
Venus
• Similar in size to Earth
• Hot, thick & poisonous atmosphere
Earth – home!
Mars
• known as the “red planet” because of its ironrich soil
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Gas Giant: large, OUTER planet that is
made mostly of gases
Jupiter
• largest planet
• known for its storm, “The Great Red Spot”
Saturn
• known for its ring system
Uranus
• known for blue-green atmosphere
Neptune
• blue-green atmosphere like Uranus
• Also has a storm, “The Great Dark Spot”
Other Rocky Bodies...
Asteroids
• asteroid belt between Mars & Jupiter
• small, rocky body that revolves around the Sun
Meteoroids – in space (like asteroids), but usually smaller
Meteors – (meteor shower); a bright streak of light caused by the
rock burning as it streaks through the atmosphere
Meteorites – piece of rock that has landed on Earth without
completely burning up, possibly making a crater
Comet – a body of ice, rock and dust that
forms a tail as it gets close to the Sun
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Light Year
A measure of how long it takes light to
travel through space in one year.
Image From: http://uniqhorns.com/images/milkyway.gif;
Definition: www.thefreedictionary.com
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Electromagnetic Spectrum
The range of all the waves that can travel
through matter as well as empty space.
R
O
Y
G
B
I
V
Scientists use different
portions of the spectrum to
learn about the universe.
Ex: light waves can tell us
what elements stars are
made & if they are moving
away or towards other
objects.
Image From: http://www.lcse.umn.edu/specs/labs/images/spectrum.gif
Definition: www.thefreedictionary.com
Theories on the Origin of the Universe
1. Steady State – has always been the same
2. Oscillating Model - began by expanding, has
slowed down & is now contracting
3. Big Bang - *the dominant theory
• 12 to 15 billion years ago
• Universe began as a dense point that exploded
• It rapidly expanded & began to cool down,
forming stars, etc.
• Evidence
 discovery of cosmic background radiation
 red shift in EM spectrum suggest it is still expanding
Click for Big Bang BrainPOP: http://www.brainpop.com/science/space/bigbang/
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