the universe and galaxies

The Universe and Galaxies

16.1

most important image

Planet Eating Star!

UniverseUniverseThe 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 Universe OccupantsOccupants

StarStar-a huge ball of hot gas that emits light

GalaxyGalaxy- a collection of millions or billions of star bound together by gravity.

Measuring Measuring DistancesDistances

Distances in the universe are beyond comprehension.

We use a unit called a light light yearyear. (9.5 x 1015 m)

It measures on how far light travels in one year.

Pg 526-527 compare distances

DistancesDistancesLight travels at 3.0 x 108 m/s or

186,000 mi/secBy car, it would take you 10

million yrs to travel one light year.

DistanceDistanceWhen you look at objects in

space, you are looking back in time.

The greater the distance, the further back in time you are looking.

DistanceDistanceOur 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.

GalaxiesGalaxiesIt 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 WayThe Milky Way

AndromedaAndromeda

Milky Way FactsMilky Way FactsChocolate covered caramel

and nougat.Only 120 caloriesMade by Mars candy

Milky Way FactsMilky Way FactsIt is made up of stars, clouds and dust

known as interstellar matter.Every star you see in our sky is part

of the milky waySpiral shape

Galaxy TypesGalaxy TypesThere are three types:

1.Spiral

2.Elliptical

3.Irregular

SpiralSpiralHave spiral arms that branch

out from a cluster of stars near the center.

Milky way and AndromedaYounger galaxiesBluish color

EllipticalEllipticalOval or egg shapedOlder galaxiesReddish in color

IrregularIrregularThese galaxies have no

defined shape.Some contain very little

clouds or dust (older)

Galaxy ClustersGalaxy ClustersClusters are groups of galaxies

held together by gravity. Some clusters contain thousands

of galaxies and are referred to as superclusters.

.

Universe is Universe is ExpandingExpanding

In 1929 Edwin Hubble concluded that the universe was expanding.

He studied the spectral lines of stars in distant galaxies.


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


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 TheoryBig Bang TheoryIt 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 TheoryBig Bang TheoryFrom this “super atom” came a

large explosion that produced everything we see today. (mass, space, time, and energy)

Evidence of Big BangEvidence of Big BangScientist 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 UniverseFuture of the Universe Three options exist:

1. It will expand forever2. It will expand then stabilize

at a given size3. It will stop expanding and

fall back on itself.

Future of the UniverseFuture of the UniverseThe amount of matter in the

universe will determine which option will be followed.

Galaxies Collide

Stars and the Sun

16.2

StarsStarsHuge 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!!!No, they don’t look like this!!!

StarsStarsConstellationsConstellations-a group of

stars appearing in a pattern as seen from Earth

Greeks thought they were characters from Mythology

Our SunOur Sun110 times bigger than the

Earth.Is a typical star.It is average in size and

temperature compared to other stars

Star PropertiesStar Properties1. Brightness1. 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. Color2. ColorColor 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. 3. Composition/Make-upComposition/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. Power4. Power

Powered by nuclear fusionHydrogen atoms combine to form

helium nuclei and releases energyEnergy moves slowly through the

layers of the sun by radiation and convection

Major Layers of StarsMajor Layers of Stars

Most inner- Core 15,000,000 KRadiative ZoneConvective ZoneMost outer layer - Corona

2,000,000 K

Energy transferred In these layers

Life of a StarLife of a StarBirth and the 1Birth and the 1stst 30 million years 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 YearsMid-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 StarThe Death of a Typical StarFusion slows causing the core to

increase in temperatureThis 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 StarThe Death of a StarFusion with in the star stops and

the star expands out as a nebula of gas

The remaining core becomes a white dwarfA small (size of Earth), very dense star that remains after fusion has stopped.

Death of Larger StarsDeath of Larger StarsLarger 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 SupernovaAfter a Supernova Two results:

1. Neutron Star- A dense dead star with surrounded by nebular gases

2. 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 View from the EarthEarth

Five planets can be seen from the Earth with the unaided eye:

Mercury, Jupiter, Venus, Mars, and Saturn


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


Astronomer Kepler showed that planets orbit are ellipses not perfect circles.

Galileo invented the telescope which helped prove Kepler and Copernicus correct.

PlanetsPlanets

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 PlanetsInner Planets

Mercury, Venus, Earth, and Mars.

Relatively small, have solid, rocky surfaces, and more dense.

MercuryMercury

Has extreme temperatures on the surface because it spins very slowly on its axis.

Has a cold side and hot sideAlmost no atmosphere and no water.Zero moons

VenusVenus

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”Venus the “evening Star”

Morning StarMorning Star

EarthEarth

Large amounts of water, rich stable atmosphere, and moderate stable temperatures give Earth perfect conditions to support life as we know it.

Insignificant Earth

MarsMars

Small amounts of water found at the poles.

There may be underground water sources

thin Atmosphere containing CO2

2 moons

Asteroid BeltAsteroid BeltDivides the inner planets from the

outer planetsAsteroid- A small rocky object that

orbits the sun. Could one of these hit our planet?Odds are small but possible

Outer PlanetsOuter PlanetsJupiter, Saturn, Uranus, NeptuneSorry PlutoLarger, thick gaseous

atmospheres.Called Gas giantsNo solid surface, very little density

JupiterJupiterBig enough to hold 1300 EarthsFamous for the great red spot

(hurricane-like storm)Atmosphere made up of H2, He,

methane, and ammonia. Has a thin ring 16 moons

SaturnSaturn Famous for its amazing ringsRings are dust rock and iceAtmosphere made up of H2, He,

methane, and ammonia. Has 18 moons

Uranus and NeptuneUranus and Neptune Called the sister planetsBoth are blue in color due to their

thick methane filled atmosphere Uranus 20 moons and a thin ringNeptune 8 moons and a thin ring

Neptune

PlutoPluto Thin nitrogen atmosphereIcy rocky, solid surfaceIts orbit is at a different angle

than the other planets.Now considered dwarf planet

due to its smaller size

Neptune

Formation of the Solar Formation of the Solar SystemSystem

Our solar system is 4.6 billion years oldNebular 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

MoonsMoonsMoons orbit planetsThe moon are also called

natural satellite

The Moon PhasesThe Moon PhasesFullCresent – less than halfQuarter- you see a half moonGibbous- you see more than halfNew- moon not visible

EclipseEclipseAn event that occurs when one

object passes into the shadow of another object

Two types: solar and lunar

NeptuneLunar Eclipse

Solar Eclipse

http://dingo.care-mail.com/cards/flash/5409/galaxy.swf

universe song

the universe and galaxies

Documents