Galileo Galilei (1564-1642)

Someone who cared!

In 1610, Galileo used a telescopethat he madeto observe the heavens.

What he observed helped to prove thatthe new “heliocentric” model was

correct.

The first thing that Galileo looked at

through his telescope was

the moon.

When he turned his telescope towards Jupiter,he was surprised by what he saw…

On the next night, the arrangement of the objects had changed.

As he continued to make observations, he as amazed at the waythe pattern of objects would change.

Galileo decided to try to figure out what was going on.

You are going to repeat Galileo’s discovery…

…by watching & plotting how Jupiter’s escorts change position

from night to night.

Each one of you will be assigned 1 colored star—red, yellow, white, or blue

to watch & plot

for each night.

The four colors to choose from are:red , yellow, white , and blue.

Choose a color and write it on the worksheet.

Plot the locationof your object

by making an X on the number line

showing where it is for that night.

Night 1

J-2 -1 1 2

numbers = millions of miles to the left or right of Jupiter

Night 1

J-2 -1 1 2

Night 2

J-2 -1 1 2

Night 3

J-2 -1 1 2

Night 4

J-2 -1 1 2

Predict the locationof your object on night 5

by making a DOT on the number line showing

where you think it will be.

Night 5

J-2 -1 1 2

Mark the actual location with an X. Was your prediction close?

Predict the locationof your object on night 6

by making a dot on the number line

showing where you think it will be.

Night 6

J-2 -1 1 2

Mark the actual location with an X. Was your prediction close?

Predict the locationof your object on night 7

by making a dot on the number line

showing where you think it will be.

Night 7

J-2 -1 1 2

Mark the actual location with an X. Was your prediction close?

Predict the locationof your object on night 8

by making a dot on the number line

showing where you think it will be.

Night 8

J-2 -1 1 2

Mark the actual location with an X. Was your prediction close?

Predict the locationof your object on night 9

by making a dot on the number line

showing where you think it will be.

Night 9

J-2 -1 1 2

Mark the actual location with an X. Was your prediction close?

Now, play “X-to-X”, connecting all of the Xs

in order from night 1 to night 9.

Here is what your pattern should look

like if you are the red colored object.

J

-2 -1 1 21

2

3

4

5

6

7

8

9

J

J

J

J

J

J

J

J

Here is what your pattern should look

like if you are the yellow colored star.

J

-2 -1 1 21

2

3

4

5

6

7

8

9

J

J

J

J

J

J

J

J

Here is what your pattern should look

like if you are the blue colored star.

J

-2 -1 1 21

2

3

4

5

6

7

8

9

J

J

J

J

J

J

J

J

Here is what your pattern should look

like if you are the white colored star.

J

-2 -1 1 21

2

3

4

5

6

7

8

9

J

J

J

J

J

J

J

J

Answer questions 1, 2, and 3. Be sure to use complete sentences.

(Make sure you use NUMBERS in your answer for question #2.)

Think about question #4 and answer it using a complete sentence.

HINT: What objects do you know about that orbit planets?

So…what are the objects and what are they doing?

They are moons that areorbiting around Jupiter.

How long does it take your object

to make one revolution around Jupiter?

J

-2 -1 1 21

2

3

4

5

6

7

8

9

J

J

J

J

J

J

J

J

To find how long it takes

to orbit Jupiter,

count how long it takes

for your object to go

from the starting

position and return to the

same location.

An example is shown for

the red moon.

Start

Two

nights

One Night

Just FYI, here is some information about the objects that

we were tracking.

Earth’sMoon, Luna

Io(red)

Europa(yellow)

Ganymede(blue)

Callisto(white)

Here are what the 4 “Galilean” moons look like...

GanymedeLargest

moon in thesolar system.

It is larger than Mercury

and Pluto.

(Blue)

Callisto

Most heavilycratered object

in the solar system

It is a deadworld…

there has beenno new surface

created for4 billion years.

(white)

Jupiter with Io and Europa

EuropaAstronomers

think thatEuropa’s icy

crust is covering an

ocean ofliquid water.

It’s surfaceshows stress

from the pull of gravity from

Jupiter andother

nearby moons.(yellow)

Io

(red)

Io has thesolar system’s

most activevolcanoes,

which spewsulfur lava.

The sulfur givesIo its unusual

colors.

Jupiter with Io, Earth & the Moon

Ganymede= BlueCallista = White

Europa = Yellow

Io = Red

Homework:Finish the

“Following in Galileo’s Footsteps”worksheet.

Be sure to use complete sentencesand to put detail into your answers.