TEK Objective
8.8 Earth and space.
The student knows
characteristics of the
universe.
Mr. McDonald
8th Grade Science
8.8 Vocabulary
Universe
Star
Nuclear fusion
Nebulae
Galaxy
Spiral galaxy
Elliptical galaxy
Irregular galaxy
Mr. McDonald
Hertzsprung-Russell
Diagram
Light year
Apparent magnitude
Absolute magnitude
8th Grade Science
The student is expected to:
A. Describe components of the universe,
including stars, nebulae, and galaxies, and
use models such as the Hertzsprung-Russell
diagram for classification
B. Recognize that the Sun is a medium sized
star near the edge of a disc-shaped galaxy of
stars and that the Sun is many thousands of
times closer to Earth than any other star.
Mr. McDonald
8th Grade Science
C. Research how different wavelengths of
the electromagnetic spectrum such as
light and radio waves are used to gain
information about the distances and
properties of components in the universe.
D. Model and describe how light years are
used to measure distances and sizes in
the universe.
E. Research how scientific data are used as
evidence to develop scientific theories to
describe the origin of the universe.
Mr. McDonald
8th Grade Science
Light Years
-distance covered by a ray of light traveling
in a year
-a measure of distance similar to meter or
kilometer, NOT TIME!!
-used to measure the distance between
stars and galaxies
-One light year is a measurement equal to
9.5 (about 10 trillion kilometers) or the
distance light travels in one year
Examples
• The nearest star to the Earth, outside our solar
system, is 39,900,000,000,000 km or 4.2 light years.
How many years would it take for light from this star
to reach Earth?
• The Milky Way Galaxy is about
1,000,000,000,000,000,000 km or 100,000 light
years. How long would it take light from the Earth to
Reach the edge of the Milky Way Galaxy
• Alpha Centauri is 5.2 light years away from Earth.
How many kilometers away is Alpha Centauri from
Earth?
Universe
-The totality of everything that exists,
including all physical matter and energy,
the planets, stars, galaxies, and the
contents of intergalactic space.
-everything you could possibly imagine
The Big Bang Theory
States 12-15 billion years ago, the universe
began with a huge fiery explosion.
States of the Universe
Expanding- Edwin Hubble states universe
has been and continues to expand
Steady State
Oscillatory
Evidence to Support Big Bang Theory
• No stars have been found to be older
than the estimated age of the
universe.
• The greater the distance of the
galaxy, the greater the red shift.
• The cosmic background radiation is
radiation left over from early development
of the universe, and is a landmark proof of
the Big Bang theory.
Components of the Universe
Watch This!!
8th Grade Science
Nebulae
--Can be formed from the remains of dead
stars/exploding stars
cloud of gas and dust in space, in which
stars form.
-The American Idol of Space
-“Where Stars are born!”
Crab Nebula
Mr. McDonald
8th Grade Science
The Pillars of Creation
8th Grade Science
Horse Head Nebula
8th Grade Science
How exactly do stars form?
Dust and gas in these clouds begins to
contract, or squash together. When things
such as clouds contract they get hotter. The
denser the cloud gets the hotter it
gets. Eventually it gets dense enough and
hot enough to ignite its hydrogen fuel,
beginning its new life as a star.
Watch This!
Stars
-a huge object in space made up of gas
(Hydrogen and Helium) that gives off light
and heat.
-Star gets so hot H turns into He and causes
heat and light= Nuclear Fusion
-closest star to the Earth is the Sun.
(about 93 million miles away)
-the second nearest star besides the Sun is
Proxima Centauri (4.2 light years away)
Life Cycles of Stars
Low Mass Star (small)
Nebula  main sequence  Red Giant 
White Dwarf
High Mass Star (Large)
Nebula  main sequence  Red Giant 
Supernova  Neutron star or Blackhole
Mr. McDonald
8th Grade Science
Stellar Evolution
8th Grade Science
Life Cycle of the Sun
8th Grade Science
Life Cycle in Action
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In this stunning picture of the giant galactic nebula NGC
3603, the crisp resolution of NASA's Hubble Space
Telescope captures various stages of the life cycle of stars
in one single view.
To the upper right of center is the evolved blue supergiant
called Sher 25. The star has a unique circumstellar ring of
glowing gas that is a galactic twin to the famous ring
around the supernova 1987A. The grayish-bluish color of
the ring and the bipolar outflows (blobs to the upper right
and lower left of the star) indicates the presence of
processed (chemically enriched) material.
Near the center of the view is a so-called starburst cluster
dominated by young, hot Wolf-Rayet stars and early O-type
stars. A torrent of ionizing radiation and fast stellar winds
from these massive stars has blown a large cavity around
the cluster.
The most spectacular evidence for the interaction of
ionizing radiation with cold molecular-hydrogen cloud
material are the giant gaseous pillars to the right and lower
left of the cluster. These pillars are sculptured by the same
physical processes as the famous pillars Hubble
photographed in the M16 Eagle Nebula.
Dark clouds at the upper right are so-called Bok globules,
which are probably in an earlier stage of star formation.
To the lower left of the cluster are two compact, tadpoleshaped emission nebulae. Similar structures were found by
Hubble in Orion, and have been interpreted as gas and
dust evaporation from possibly protoplanetary disks
(proplyds). The "proplyds" in NGC 3603 are 5 to 10 times
larger in size and correspondingly also more massive.
This single view nicely illustrates the entire stellar life cycle
of stars, starting with the Bok globules and giant gaseous
pillars, followed by circumstellar disks, and progressing to
evolved massive stars in the young starburst cluster. The
blue supergiant with its ring and bipolar outflow marks the
end of the life cycle.
The color difference between the supergiant's bipolar
outflow and the diffuse interstellar medium in the giant
nebula dramatically visualizes the enrichment in heavy
elements due to synthesis of heavier elements within stars.
Lifespan
Related to their starting masses.
Smallest-live about 100 billion years
Medium-live about 10 billion years
(Sun)
Largest -live about few billion years
Mr. McDonald
8th Grade Science
Watch This!
• Size of STARS
The Sun
-medium sized,
middle aged star
-main sequence star
-center of our solar
system
-93 million miles
away
8th Grade Science
Galaxies
Galaxy large group of stars, dust, and gas held
together by gravity.
-can contain up to a trillion stars
-up to 170 billion galaxies in the visible universe
3 types:
1. Spiral
2. Elliptical
3. Irregular
8th Grade Science
Spiral Galaxy
-disk-shaped with a large mass in the middle
and arms that spiral out from the mass.
-the arms revolve around the center
-Ex. Milky Way (Our galaxy)
8th Grade Science
Spiral Galaxy
8th Grade Science
Elliptical Galaxy
-shaped like a flattened or partially deflated
football.
8th Grade Science
Irregular Galaxy
-does not have a distinct shape
-least common of the 3
-nearest galaxies to the Milky Way galaxy
are irregular.
8th Grade Science
Irregular Galaxy
8th Grade Science
Other Components in Universe
• Planets
Our Solar System – 8
1. A planet must orbit a
sun (a star)
2. be large enough so
that its own gravity
molds it into a
spherical shape,
3. it must have an orbit
free of other small
objects (Sorry Pluto)
4. My Very Elegant
Mother Just Served
Us Nachos
Exoplanet- a planet
that orbits a star outside
the solar system
8th Grade Science
Galilean Moons
Galileo Galilei discovered Jupiter's 4 largest moons using a
homemade telescope
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Io- covered with giant volcanoes which erupt of sulfuric acid
Europa – a cold, smooth, ice covered world
Ganymede -has a liquid water ocean underneath its icy exterior
Callisto -almost the same size as the planet Mercury
Comets
small body in
space consists
of dust, gas, and
ice. Tail is the
ice vaporizing as
it approaches
star.
Asteroids
small solar system
bodies that orbit
the Sun. Made of
rock and metal,
they can also
contain organic
compounds.
Meteoroid, Meteor, Meteorite
• Meteoroid -a small rock or particle of debris in our
solar system
• Meteor -A meteoroid that burns up as it passes
through the Earth’s atmosphere= Shooting STAR!!
• Meteorite -survives falling through the Earth’s
atmosphere and colliding with the Earth’s surface.
Universe Poster
You will create a concept poster that includes all of the Characteristics of
the Universe covered in class. You will design and draw your own
Universe and you must include:
• 3 Types of Galaxies
• Nebulae and a depiction of what happens here ( star being born)
• Types of stars (White Dwarf, Main Sequence, Super Giants) with a caption
stating temperature, size and age (Use text)
• Draw a life cycle of a Low Mass Star and High Mass Star and use captions
to tell the story and explain the sequential events
• Comets, Asteroids, and Meteors with captions describing them and in the
correct location where you would find each one
• Planets and Galilean Moons
• Our Solar System (on the edge of the Milky Way Galaxy) including the Sun
and 8 planets in its Orbit. Add captions to the Sun and add information from
your notes including size, temperature, age,etc.
**This is NOT a One Page Notes assignment. This should look like a
picture of outer space with illustrations of all the concepts listed above.**
EVERYTHING MUST BE COLORED!!
Types of Stars
-stars vary in age, color, composition and
size.
8th Grade Science
Size
Smallest-diameter of 10-30 km (5-20 miles)
Medium-diameter of 1.4 million km
(865,000 miles)
Large-diameter of 640 million km
(398 million miles)
8th Grade Science
Composition
-Younger stars mainly composed of
hydrogen and helium
-Older stars will create other elements such
as carbon and oxygen.
-Stars die when iron is formed.
White Dwarfs
Smallest
25,000 C
or
45,000 C
Main Sequence
medium size
Less hot
Super Giants
largest
3,000 C
or
5,400 C
Least hot
Lifespan
Related to their starting masses.
Smallest-live about 100 billion years
Medium-live about 10 billion years (Sun)
Largest -live about few billion years
Apparent Magnitude
A measure of the amount of light from a star
that is received on Earth.
-the brighter the star appears, the lower
the numerical value of its magnitude
8th Grade Science
Absolute Magnitude
A measure of the amount of light a star
gives off.
-the brightness a star would be as seen
from a distance of 10 parsecs
(1 parsec = 3.2 light years)
10 Parsecs = 191,735,281,000,000 miles
Hertzsprung-Russell Diagram
-diagram that measures luminosity (absolute
magnitude) as well as temperature of a
star.
The luminosity of a star is a measure of its
brightness
Mr. McDonald
8th Grade Science
Hertzsprung-Russell Diagram
Mr. McDonald
8th Grade Science
Electromagnetic Waves (EM)
Waves that can travel through matter or
space and are produced by the motion of
electrically charged particles.
Spectrascope – a device used to split light
into different wavelengths to determine the
chemical composition of objects such as
stars and elements.
Electromagnetic Wave Spectrum
Types of EM waves
Radio
Micro
Visible
Infrared
UV
X-ray
Gamma
Visible Light
-the only EM waves humans can see.
-made up of white light
-includes all the colors of the rainbow
Red
Orange
Yellow
Green
Blue
Indigo
Violet
Red Shift
-shift in the light of a retreating object toward
red wavelengths, caused by the Doppler
effect
RED SHIFT
Mr. McDonald
8th Grade Science
Blue Shift
-a shift in the wave-length of radiation emitted by
an object when it is approaching us
-the light appears with a shorter wavelength, and
hence bluer
BLUE SHIFT
Mr. McDonald
8th Grade Science
Doppler Shift
Watch This
RED SHIFT
BLUE SHIFT
Mr. McDonald
8th Grade Science
Speed of Light
• All types of EM Frequency
Waves travel at the speed of
light!
How can we tell what elements
Stars are made from?
• Each element absorbs different colors
from the color spectrum. The show
up as dark SPECTRAL LINES and
they look like a bar code. Each
element has a different code. When
we receive light from stars, each one
emits a specific code which then tells
us what elements are present in that
star.