Download The Universe

Our Universe
Billions of galaxies made up of billions of stars
Our Own Solar System
The Sun and the Planets that orbit it
The Sun – Our Star
The closest star to Earth
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Medium size
Yellow
Main Sequence Star
150,000,000 Km (93
Million miles) away.
• 4.5 - 5 billion years old
• Will last about another
5 billion years
• Located near the edge
of our disc shaped
galaxy – The Milky Way
The Suns Planets
Celestial bodies that orbit a star
Our Milky Way Galaxy
Comets
Rocky material made of gas dust and ice that orbit the sun
Meteors
Space Rocks known as shooting stars when they
enter the Earth’s atmosphere.
Become meteorites when they hit the Earth’s surface
Asteroids
Small rocky bodies known as minor planets
Orbit the sun mainly between Mars and Jupiter (asteroid belt)
Stars
Huge bright balls of gas
What are Stars?
• Gigantic spheres of gases held together
by gravity
• Generate huge amounts of energy
because of nuclear reactions of
hydrogen and other elements.
• Radiate electromagnetic radiation.
– Light, heat and other forms of energy
• There are 100 billion stars in our own
galaxy!
Stars
• The Sun is the closest star
to Earth – 150,000,000 km
away
• The next closest star is
Proxima Centauri –
39,900,000,000,000 km away
– 4.2 light years
• The Sun
• Stars are extremely far
away!!!
• The Sun is thousands of
times closer to Earth than
other stars
• Proxima Centauri
Light Years
Unit of measurement for distances in Space
• The distance that light travels in one year.
• Light travels at about 300,000 km/sec.
– 186,000 miles/sec
• One light year is equal to 9.46 trillion km
(9,461,000,000,000).
– 5.87 trillion miles (5,870,000,000,000)
• Light travels faster than anything else known
to man.
Classifying Stars
Class
Color
Surface Temp.
(degrees Celsius)
Elements
detected
Examples of
stars
O
B
Blue
Above 30,000
Helium
10 Lacertae
Blue-white
10,000 - 30,000
Helium and
Hydrogen
Rigel, Spica
A
F
Blue-white
7,500 - 10,000
Hydrogen
Vega, Sirius
Yellowwhite
6,000 - 7,500
Hydrogen and
heavier
elements
Canopus,
Procyon
G
Yellow
5,000 - 6,000
Calcium and
other metals
The sun,
Capella
K
Orange
3,500 - 5,000
Calcium and
Molecules
Arcturus,
Aldebaran
M
Red
Less than 5,000
Molecules
Betelgeuse,
Antares
Hertzprung–Russel (H-R) Diagram
- a graph that shows the relationship between a star’s surface
temperature and it’s absolute magnitude.
H-R Diagram
Analyze the graph!
Analyzing the H-R Diagram
Brightest Stars
Y-Axis
Brightness
Dimmest Stars
Hottest Stars
X-Axis
Temperature
Coolest Stars
Stages of a Stars Life Cycle
Nebulas – Stellar Nurseries
• Giant clouds of gas
and dust in space
• Where new stars are
formed
GALAXIES
Large group of stars in space held
together by Gravity
Classified by Shape - Sprial/Disc, Elliptical, Irregular Shaped
Spiral/Disc Shaped Galaxy
• Andromeda Galaxy
– Large center with
spiral arms
traveling around it
– Ex. Andromeda
Galaxy and our
Milky Way Galaxy
– Our Sun is located
near the edge of
the Milky Way
Galaxy
Our Milky Way
• Sprial/Disc
Shaped Galaxy
• 100,000 Light
Years Across
• Black Hole at the
center
• The Sun is near
the edge of our
galaxy in one of
the spiral arms.
Elliptical Galaxy
• M 87 Galaxy
– Massive blobs of
stars that have
very bright
centers
– Very little gas and
dust
– Contain mostly old
stars.
Irregular Galaxy
• Large Megellanic Cloud
– Don’t fit into
any other class.
– Have irregular
shapes
– Contain mostly
young stars and
lots of gas
Supernova
Death of a star by explosion
Black Holes
Gravity is so strong not even light can escape
Believed to be the center of most galaxies
Theories on the Origin of the Universe
How did we get here?
• The Big Bang Theory – states that the
universe began with a big explosion.
• Steady State Theory - the universe
has always been here and always will.
• There are many more theories
The Big Bang Theory
• Most dominant
theory
• States that the
universe was created
from a cosmic
explosion that
hurled matter in all
directions
• Occurred about 1314 billion years ago
Evidence that supports
the big bang
• Cosmic background radiation
– radiation coming from all directions in
space, believed to be left over from the big
bang.
• The observable expansion of the
universe (Red Shift).
– Galaxies are moving away from each other
Spectroscopes/Spectrometers
• Used to gain information about
properties of components in
the Universe
• Shows differences in the
elements that make up a star.
Electromagnetic Waves
• Light Waves that Astronomers can use
to gain information about distances and
properties of components of the
universe.
Electromagnetic Waves
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Radio waves
Microwaves
Infrared waves
Visible Light
Ultraviolet waves
X-Rays
Gamma Rays
Cosmic Rays
From lowest to highest
frequency (energy)
Electromagnetic Waves Research
1. Look up Electromagnetic Waves using
your netbook.
2. Define electromagnetic waves
3. List all the electromagnetic waves in
the electromagnetic spectrum
4. Describe what each type of wave is
used for by humans.