Download ch16 b - Manasquan Public Schools

The Universe
and Galaxies
16.1
 most important image
Planet Eating
Star!
Universe
The sum of all matter and
energy that exists, that has ever
existed, and that will ever exist.
We will focus on the belief that
there is only one universe
Universe
Occupants
Star-a huge ball of hot gas
that emits light
Galaxy- a collection of
millions or billions of star
bound together by gravity.
Measuring
Distances
Distances in the universe are
beyond comprehension.
We use a unit called a light
year. (9.5 x 1015 m)
It measures on how far light
travels in one year.
Pg 526-527 compare distances
Distances
Light travels at 3.0 x
8
10
m/s or
186,000 mi/sec
By car, it would take you
10
million yrs to travel one light
year.
Distance
When you look at objects in
space, you are looking back in
time.
The greater the distance, the
further back in time you are
looking.
Distance
Our sun is only 1.5 x1011 m
away, which less than one light
year.
The next closest star is Alpha
Centauri is 4.3 light years
away.
Galaxies
It is estimated that there are
100 billion galaxies.
Our galaxy is the Milky Way.
But the nearest galaxy is
2 million Lt.Yrs away. It is
named Andromeda
The Milky Way
Andromeda
Milky Way Facts
Chocolate covered caramel
and nougat.
Only 120 calories
Made by Mars candy
Milky Way Facts
It is made up of stars, clouds and dust
known as interstellar matter.
Every star you see in our sky is part
of the milky way
Spiral shape
Galaxy Types
There are three types:
1. Spiral
2. Elliptical
3. Irregular
Spiral
Have spiral arms that branch
out from a cluster of stars
near the center.
Milky way and Andromeda
Younger galaxies
Bluish color
Elliptical
Oval or egg shaped
Older galaxies
Reddish in color
Irregular
These galaxies have no
defined shape.
Some contain very little
clouds or dust (older)
Galaxy Clusters
Clusters are groups of galaxies
held together by gravity.
Some clusters contain thousands
of galaxies and are referred to as
superclusters.
.
Universe is
Expanding
In 1929 Edwin Hubble
concluded that the universe
was expanding.
He studied the spectral lines
of stars in distant galaxies.
Universe is
Expanding
He found that distant galaxies
shifted to the Red end of the
spectrum.
This indicated that waves were
stretching out and thus moving
away from us.
(wavelengths were getting bigger)
Daily Journal
 If Hubble had observed that the spectral
lines in light from every galaxy were
shifted toward the blue end of the
spectrum, what might he have concluded
about the universe?
 Unscramble:


BAGNBIG
OENLTLTISNCOA
Universe is
Expanding
He concluded that galaxies are
moving away from each other.
This means that the universe is
expanding.
Hubble Telescope
How the Universe was
Created?
How the Universe was Created?
Big Bang Theory
It is generally believed that the
universe is 15 billion yrs old.
This theory begins with the
premise that nothing but an “atom”
existed before the Big Bang.
Big Bang Theory
From this “super atom” came a
large explosion that produced
everything we see today.
(mass, space, time, and
energy)
Evidence of Big Bang
 Scientist working NJ detected cosmic
background radiation in the form of
microwaves.
 This radiation was predicted by the theory.
 The radiation has shown a cooling trend which
has allowed scientist to measure the overall
temperature of the universe. (2.7 K)
 Also the amount hydrogen (most common
element)
Future of the Universe
 Three options exist:
1. It will expand forever
2. It will expand then stabilize
at a given size
3. It will stop expanding and
fall back on itself.
Future of the Universe
 The amount of matter in the
universe will determine
which option will be
followed.
Galaxies Collide
Stars and the
Sun
16.2
Stars
Huge balls of gas that emit a
tremendous amount of light
and heat.
6000 stars can be seen with
the unaided eye from Earth.
No, they don’t look like this!!!
Stars
Constellations-a group of
stars appearing in a pattern as
seen from Earth
Greeks thought they were
characters from Mythology
Our Sun
110 times bigger than the
Earth.
Is a typical star.
It is average in size and
temperature compared to other
stars
Star Properties
1. Brightness
Brightness depends on star’s
temperature (intensity), size, or
distance from the Earth.
Sirius the brightest star besides the sun, in our sky.
2. Color
Color of a star is related to its
temperature.
Lower the wavelength, the
higher the frequency, the hotter
the star.
Stars emitting a blue color are
the hottest-most energy.
3.
Composition/Make-up
Scientist use spectral lines to
reveal the composition of stars.
Each element has its own
unique spectral line.
~90% H, 9.9% He, .1% others
Spectral Lines from Different elements
4. Power
Powered by nuclear fusion
Hydrogen atoms combine to form
helium nuclei and releases energy
Energy moves slowly through the
layers of the sun by radiation and
convection
Major Layers of Stars
Most inner- Core 15,000,000 K
Radiative Zone
Convective Zone
Energy transferred
In these layers
Most outer layer - Corona
2,000,000 K
Life of a Star
st
Birth and the 1 30 million years
Stars are born in a cloud of
dust and gas called Nebulas
In these clouds protons start
moving very rapidly and move
very close to each other,
allowing fusion to take place.
Mid-Life and the Next 5 billion Years
Fusion reactions maintain a
equilibrium balance with in the
star.
Our sun and 90% of other stars
are in this stage.
The Death of a Typical Star
Fusion slows causing the core to
increase in temperature
This cause the outer layers
expand out.
The star becomes a red giant
A large reddish star late in its life
cycle that fuses helium into carbon
and oxygen.
The Death of a Star
Fusion with in the star stops and
the star expands out as a nebula
of gas
The remaining core becomes a
white dwarf
A small (size of Earth), very dense
star that remains after fusion has
stopped.
Death of Larger Stars
Larger star expand into Supergiants.
 An
extremely large star that creates
elements as heavy as iron
When fusion stops, they have a more
dramatic death, a supernova.
A
powerful explosion that occurs
when a massive star dies.
Supergiant Star
Supernova
After a Supernova
 Two results:
1.
2.
Neutron StarA dense dead star with surrounded by
nebular gases
Black hole-
An object so massive and dense that
not even light can escape its gravity
Black Hole
The Solar
System
16.3
View from the
Earth
Five planets can be seen
from the Earth with the
unaided eye:
Mercury, Jupiter, Venus,
Mars, and Saturn
View from the
Earth
It was once thought that the
Earth was the center and not
the sun.
Copernicus was the first to
say the planets orbit the sun
View from the
Earth
Astronomer Kepler showed that
planets orbit are ellipses not
perfect circles.
Galileo invented the telescope
which helped prove Kepler and
Copernicus correct.
Planets
Any massive body of matter orbiting a
star.
planets do not give off their own light,
they only reflect and absorb star light.
This is why it is difficult for
astronomers to discover planets.
Planet Song
Inner Planets
Mercury, Venus, Earth, and
Mars.
Relatively small, have solid,
rocky surfaces, and more
dense.
Mercury
Has extreme temperatures on the
surface because it spins very slowly
on its axis.
Has a cold side and hot side
Almost no atmosphere and no water.
Zero moons
Venus
Hottest planet due to its very thick
atmosphere of CO2 and sulfuric acid
(Extreme green house effect)
Because of its atmosphere, it also reflects
the most light.
Sometimes called the “Morning/Evening
Star”
No moons
Venus the “evening Star”
Morning Star
Earth
Large amounts of water, rich
stable atmosphere, and
moderate stable temperatures
give Earth perfect conditions to
support life as we know it.
Insignificant Earth
Mars
Small amounts of water found at
the poles.
There may be underground water
sources
thin Atmosphere containing CO2
2 moons
Asteroid Belt
Divides the inner planets from the
outer planets
Asteroid- A small rocky object that
orbits the sun.
Could one of these hit our planet?
Odds are small but possible
Outer Planets
Jupiter, Saturn, Uranus, Neptune
Sorry Pluto
Larger, thick gaseous
atmospheres.
Called Gas giants
No solid surface, very little density
Jupiter
Big enough to hold 1300 Earths
Famous for the great red spot
(hurricane-like storm)
Atmosphere made up of H2, He,
methane, and ammonia.
Has a thin ring
16 moons
Saturn
Famous for its amazing rings
Rings are dust rock and ice
Atmosphere made up of H2, He,
methane, and ammonia.
Has 18 moons
Uranus and Neptune
Called the sister planets
Both are blue in color due to their
thick methane filled atmosphere
Uranus 20 moons and a thin ring
Neptune 8 moons and a thin ring
Neptune
Pluto
Thin nitrogen atmosphere
Icy rocky, solid surface
Its orbit is at a different angle
than the other planets.
Now considered dwarf planet
due to its smaller size
Neptune
Formation of the Solar
System
Our solar system is 4.6 billion years old
Nebular Model Theory-
-a model that describes the sun forming
together out of a cloud of dust and gas
--Inner planets formed from rocks and dust,
and the gas giants formed from gases
farther out
Moons
Moons orbit planets
The moon are also called
natural satellite
The Moon Phases
Full
Cresent – less than half
Quarter- you see a half moon
Gibbous- you see more than half
New- moon not visible
Eclipse
An event that occurs when one
object passes into the shadow
of another object
Two types: solar and lunar
Lunar
Eclipse
Neptune
Solar Eclipse
http://dingo.care-mail.com/cards/flash/5409/galaxy.swf
 universe song
 fun