Someone who cared! Galileo Galilei (1564-1642)

In 1610, Galileo. used a telescope. that he made. to observe In 1610, Galileo used a telescope that he made to observe the heavens. What he observed helped to prove that the 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 way the 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 The four colors to choose from are: red , yellow, white , and blue. Choose a color and write it on the worksheet.

Plot the location of your object by making an X on the number line showing where it is for that night.

Night 1 -2 -1 1 2 J numbers = millions of miles to the left or right of Jupiter

Night 1 -2 -1 1 2 J

Night 2 -2 -1 1 2 J

Night 3 -2 -1 1 2 J

Night 4 -2 -1 1 2 J

Predict the location of your object on night 5 by making a DOT on the number line showing where you think it will be.

Mark the actual location with an X. Was your prediction close? Night 5 -2 -1 1 2 J Mark the actual location with an X. Was your prediction close?

Predict the location of your object on night 6 by making a dot on the number line showing where you think it will be.

Mark the actual location with an X. Was your prediction close? Night 6 -2 -1 1 2 J Mark the actual location with an X. Was your prediction close?

Predict the location of your object on night 7 by making a dot on the number line showing where you think it will be.

Mark the actual location with an X. Was your prediction close? Night 7 -2 -1 1 2 J Mark the actual location with an X. Was your prediction close?

Predict the location of your object on night 8 by making a dot on the number line showing where you think it will be.

Mark the actual location with an X. Was your prediction close? Night 8 -2 -1 1 2 J Mark the actual location with an X. Was your prediction close?

Predict the location of your object on night 9 by making a dot on the number line showing where you think it will be.

Mark the actual location with an X. Was your prediction close? Night 9 -2 -1 1 2 J 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.

-2 -1 1 2 J 1 J 2 J 3 J 4 J 5 J 6 J 7 J 8 J 9

Here is what your pattern should look like if you are the yellow colored star.

-2 -1 1 2 J 1 J 2 J 3 J 4 J 5 J 6 J 7 J 8 J 9

Here is what your pattern should look like if you are the blue colored star.

-2 -1 1 2 J 1 J 2 J 3 J 4 J 5 J 6 J 7 J 8 J 9

Here is what your pattern should look like if you are the white colored star.

-2 -1 1 2 J 1 J 2 J 3 J 4 J 5 J 6 J 7 J 8 J 9

Answer questions 1, 2, and 3. Be sure to use complete sentences 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 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 are orbiting around Jupiter.

How long does it take your object to make one revolution around Jupiter?

An example is shown for the red moon. 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. -2 -1 1 2 Start J 1 J 2 One Night Two nights J 3 J 4 J 5 J 6 J 7 J 8 J 9

Just FYI, here is some information about the objects that we were tracking.

Earth’s Moon, Luna

Here are what the 4 “Galilean” moons look like... Io (red) Europa (yellow) Ganymede (blue) Callisto (white)

Largest moon in the solar system. It is larger than Mercury and Pluto. Ganymede Largest moon in the solar system. It is larger than Mercury and Pluto. (Blue)

Most heavily cratered object in the solar system Callisto Most heavily cratered object in the solar system It is a dead world… there has been no new surface created for 4 billion years. (white)

Jupiter with Io and Europa

Astronomers think that Europa’s icy crust is covering an ocean of liquid water. It’s surface shows stress from the pull of gravity from Jupiter and other nearby moons. (yellow)

The sulfur gives Io its unusual colors. Io has the solar system’s most active volcanoes, which spew sulfur lava. The sulfur gives Io its unusual colors. (red)

Jupiter with Io, Earth & the Moon

Io = Red Europa = Yellow Callista = White Ganymede= Blue

Homework: Finish the “Following in Galileo’s Footsteps” worksheet. Be sure to use complete sentences and to put detail into your answers.