 Write down your objectives and homework in your notebook.  Why is gravity really important to the formation of new planets?  Write down your response in your notebook.  You will have 10 minutes to complete the do now.  Next share your answers with the class.

Gravity is responsible for the formation and shape of planets… and stars. Gravity is the force that keeps moons in orbit around a planet (“revolution”).

 Sort the galaxy pictures into 3 groups based on the characteristics you observe.  The galaxy sorting activity is found in brown envelopes on the teachers desk next to the pink, blue, green, file folders. The teacher will pass this out to each table.  Each group consisting of two students will choose one set of galaxy to sort.  Please sort the galaxies based on size, form, shape, color or anything you can think of and justify your answer to the class.

How can galaxies be classified?

 Galaxies are clusters of billions of stars that may have different shapes.  Galaxies can be classified by their shape type.

 The universe is a HUGE place that contains billions of galaxies, including our Milky Way galaxy.  Scientists believe that there is a black hole at the center of each galaxy. facts-formation-discovery-sdcmp.html

 Spiral galaxies are disk shaped with a bulge in the center and arms that spiral out from the bulge.  The shape is caused by rotation (spinning).

 Barred spiral galaxies are created during angular momentum they begin to spin next they flatten out with a central mass in the middle creating the bar

 Elliptical galaxies are shaped like a deflated football.  Can have a round or elliptical (oval) shape.  They rotate slowly or not at all.

 Irregular galaxies do not have a distinct shape.  This is the most uncommon type of galaxy.

Spiral GalaxyElliptiical GalaxyIrregular Galaxy · Central bulge: Old stars · Spiraling arms: New Stars, gas, dust, planets · Sun is one of the billions of stars. · Milky way is a spiral galaxy A barred spiral is an type of a spiral galaxy. · Made of many stars and looks like a snowball · Largest galaxies · 5 trillion stars · Stopped making new stars 10 billion years ago · No clear shape · Formed galaxies collide · Few as 10 million stars · Smallest galaxies

 Based off the information you have just learned please sort the galaxies now in the correct classification.  Write down if you were correct the first time, if so how did you know how to classify them?  If you were incorrect sorting them, what have you learned about classification?

 Create a Venn Diagram to show the similarities and differences between the two galaxies below.

Go to Ms. Ryan’s Weebly account under the Daily Agenda page click on the cotton ball activity. The brown constructions paper is in cubby hole which is located on top of the black filing cabinet near the teachers desk. The cotton balls are located inside the teacher’s desk in the bottom right hand corner. The teacher will give these supplies to students to pass out.