Galaxy DGalaxy A Galaxy B Galaxy C1. Name these galaxies according to their shape.

2. Galaxies that travel together through space are called –

A constellationsB solar systemsC Milky WaysD Clusters

3. What do all galaxies have in common?

A They are the same shape.B They are made of stars.C They are the same distance from Earth.D They travel around the Sun.

Bell Ringer 4.6 2/22/11 Bell Ringer 4.6 2/22/11 copy questions 2 and 3 with the answer copy questions 2 and 3 with the answer

choiceschoices

Galaxy DGalaxy A Galaxy B Galaxy C

1. Name these galaxies according to their shape.

2. Galaxies that travel together through space are called –

A constellationsB solar systemsC Milky WaysD Clusters

3. What do all galaxies have in common?

A They are the same shape.B They are made of stars.C They are the same distance from Earth.D They travel around the Sun.

Spiral Elliptical Irregular Spiral

September 24, 2007September 24, 2007

1.1. Bell RingerBell Ringer2.2. Turn in “KWL” / Red Shift ActivityTurn in “KWL” / Red Shift Activity3.3. Complete Galaxy FoldableComplete Galaxy Foldable4.4. Galaxy/Light-year NotesGalaxy/Light-year Notes

Today’s ObjectivesToday’s ObjectivesTo be able to differentiate between the To be able to differentiate between the

three types of galaxies.three types of galaxies.

To understand the use of light-years and To understand the use of light-years and be able to apply the measurement to stars be able to apply the measurement to stars and galaxies.and galaxies.

GalaxiesGalaxiesGalaxies are made up of billions and Galaxies are made up of billions and

billions ofbillions of

GalaxiesGalaxiesGalaxies are made up of billions and Galaxies are made up of billions and

billions of billions of starsstars..

GalaxiesGalaxiesGalaxies are made up of billions and Galaxies are made up of billions and

billions of billions of starsstars..Many galaxies make up Many galaxies make up

GalaxiesGalaxiesGalaxies are made up of billions and Galaxies are made up of billions and

billions of billions of starsstars..Many galaxies make up Many galaxies make up clusters.clusters.

GalaxiesGalaxiesGalaxies are made up of billions and Galaxies are made up of billions and

billions of billions of starsstars..Many galaxies make up Many galaxies make up clusters.clusters.

What is the name of our galaxy???What is the name of our galaxy???

The Milky Way!!!!The Milky Way!!!!

The Milky Way!!!!The Milky Way!!!!The Milky Way is Located the cluster of The Milky Way is Located the cluster of

galaxies called thegalaxies called the

The Milky Way!!!!The Milky Way!!!!The Milky Way is Located the cluster of The Milky Way is Located the cluster of

galaxies called the galaxies called the Local GroupLocal Group..

3 Types of Galaxies3 Types of Galaxies

Galaxy DGalaxy A Galaxy B Galaxy C

3 Types of Galaxies3 Types of Galaxies

Galaxy DGalaxy A Galaxy B Galaxy C

3 Types of Galaxies3 Types of Galaxies

Spiral Elliptical Irregular Spiral

What shape is our galaxy?What shape is our galaxy?

What unit do astronomers use to measure What unit do astronomers use to measure the distances between stars and galaxies?the distances between stars and galaxies?

What unit do astronomers use to measure What unit do astronomers use to measure the distances between stars and galaxies?the distances between stars and galaxies?

Light-YearsLight-Years

What unit do astronomers use to measure What unit do astronomers use to measure the distances between stars and galaxies?the distances between stars and galaxies?

Light-YearsLight-Years

A light-year is the distance that light travels A light-year is the distance that light travels in one year.in one year.

What unit do astronomers use to measure What unit do astronomers use to measure the distances between stars and galaxies?the distances between stars and galaxies?

Light-YearsLight-Years

A light-year is the distance that light travels A light-year is the distance that light travels in one year.in one year.

Light travels at 300,000 kilometers in one second! Think of how far light Light travels at 300,000 kilometers in one second! Think of how far light can travel in one year…can travel in one year…

9.5 trillion kilometers!!9.5 trillion kilometers!!

Light-Years Away???Light-Years Away???Light-year is a measure of distance…not Light-year is a measure of distance…not

time!!time!!

Proxima Centauri is the closest star to Proxima Centauri is the closest star to Earth other than the Sun. This star is 4.3 Earth other than the Sun. This star is 4.3 light years away.light years away.

Therefore, it takes 4.3 years for the light Therefore, it takes 4.3 years for the light from that star to reach Earth.from that star to reach Earth.

So…So… If a star that is located 65 light years away If a star that is located 65 light years away

from Earth burns out at this very moment, from Earth burns out at this very moment, how long will it be before we know it?how long will it be before we know it?

So…So… If a star that is located 65 light years away If a star that is located 65 light years away

from Earth burns out at this very moment, from Earth burns out at this very moment, how long will it be before we know it?how long will it be before we know it?

Yep!!!Yep!!! 65 Years65 Years