6.5 Galaxies

Galaxies

Unit 6: Light
Mr. Jake V.

Here’s what you’ll learn in this lesson:

1.

Describe a galaxy in terms of stellar dust and gas, stars and
planetary systems

2.

Describe asteroids as rocks, smaller than planets, and
describe their formation from rocks left over from the
formation of a planetary system

3.

Describe gravity as a force of attraction between any two
objects and describe how the size of the force is related to the
masses of the objects

4.

Describe a vacuum as a space devoid of matter

LEARNING OBJECTIVES

• I understand what galaxies are.

• I can recall the three shapes of galaxies.

• I can recall that galaxies contain stellar dust and gas, stars and solar systems.

• I can understand that gravity holds all the parts of a galaxy together in space.

• I can describe what is meant by the term asteroid.

• I can recall where most asteroids in the Solar System are found.

• I know that asteroids are formed from rocks left over from the formation of the Solar System.

• I know that some asteroids pass close by Earth and can, from time to time, impact Earth.

Success Criteria

Direction:

NO SKIPPING!

Watch the video in the next slide. DO NOT SKIP to answer the questions after. Pause the video if you need to take down notes about the topic presented in the video.

Some text here about the topic of discussion

If you look at the sky on a clear night, far away from any lights, you can see a milky band across the sky. This milky band is part of the GALAXY where we live, called the MILKY WAY.

Open Ended

In your own words, what is a galaxy?

The reason why our own galaxy looks like a band across the sky is because of the shape of the galaxy. The milky way is a spiral galaxy.

There are other galaxies in the universe besides our own. The word universe is used to describe all of space and everything in it.

These other galaxies have different shapes, and they are classified according to shape. They are called elliptical galaxies or irregular galaxies.

​Shapes of Galaxies

Multiple Select

What are the OTHER SHAPES of the galaxy aside from the spiral ones?

Select two answers

• round

• elliptical

• regular

• irregular

What are galaxies made of?

Galaxies are made from stellar dust, gas, stars and solar system held together by GRAVITY.

Stellar dust is the dust found in space.

The earth is travelling through a cloud of stellar dust.

The gravity holding a galaxy is strong because galaxies have very large mass.

be

How many galaxies are there?

Scientists have counted the galaxies in one part of space. The scientists then multiplied this number up to estimate the number of galaxies in the Universe.



The answer they got was 100 000000000 galaxies!


Estimates such as this may not be accurate.



There could be more or fewer galaxies in the part of space that the scientists counted compared with the rest of the Universe. Also, the scientists may not know the total volume of the Universe accurately

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks

Dropdown

What are the three different shapes of galaxies? ​

Select answer

​ ​

Select answer

​ ​ ​

Select answer

Open Ended

What is galaxy made up of or state its concentration?

Multiple Select

Which of these are found in galaxies?

Choose all that are correct from the choices.

• planet

• star

• universe

• stellar gas

Multiple Select

Which of these are found in galaxies?

• planet

• universe

• star

• stellar gas

Multiple Choice

What do you call to the FORCE that holds all the composition of the galaxy?

• friction

• air resistance

• gravity

• magnet

Rocks in SPACE

Unit 6: Light
Mr. Jake V.

Asteroids

Asteroids are objects made from rock that orbit the sun.

Asteroids range in size up to 975 km across.

Most asteroids are not regular shapes, just as rocks on Earth are not regular shapes.

Asteroids

Most of the asteroids in the solar system orbit the sun between the orbit of Mars and Jupiter. This part of the solar system is called the asteroid belt.

Open Ended

Describe what is meant by the term "asteroid".

Multiple Select

Which statements describe what asteroids?

Select all that are correct.

• all asteroids are larger than planets

• asteroids are made from rock

• asteroids can have irregular shapes

• all asteroids orbit the Earth.

Multiple Choice

Where is the asteroid belt?

Choose one.

• closer to the Sun than Mercury

• between the orbit of Venus and Earth

• between the orbis of Mars and Jupiter

• between the orbits of Uranus and Neptune

Ceres

The largest asteroid is called Ceres and was discovered in the year 1801.

Scientists thought and believed it was a new planet. As Ceres looked much smaller than a planet. Asteroid was introduced.

Ceres

Ceres looks like a small planet. It is round.

Ceres also has a core, a mantle, and a crust like some planets.

Ceres would have become a planet if it had continued to grow during the formation of the Solar System.

Fill in the Blanks

Open Ended

Describe where the rocks came from to form asteroids.

ITOKAWA

Samples from Itokawa has given the scientists more evidence about how solar system formed.

Itokawa appears to be made from lumps of rock. These lumps of rock appear to have come from other small planets or moons which have broken by impacts.

ITOKAWA

The force of gravity holding the lumps of rock together is weak because the asteroid is relatively small object.

When an asteroid passes a large object like a planet, changes its shape of the asteroid.

The force of gravity in these asteroids would be too weak to hold separate pieces of rock together failing to make a planet.

Travel back in time on how planets were formed and how asteroids were formed.

Watch the video in the next slide, and take note some important notes. DO NOT SKIP NOR FORWARD THE VIDEO.

In a sheet of paper, list down all the information that you learned and discovered from watching the documentary video.

Turn them in to your teacher for checking.

Summary