1. Show what you know! When an astronaut performs a space walk, she
A. Has a mass of zero
B. Is weightless
C. Has the same mass as on Earth
D. Has the same weight as on Earth
As the distance between two objects increases, the gravitational attraction between them
A. Decreases C. Stays the same
B. Increases D. Doubles

2. Which pie chart accurately shows the ratio of gases in the Earth’s atmosphere?
Nitrogen 21%
Oxygen 78%

4. Mass vs. Weight

5. Shout it out!!!
Which objects would have the greatest gravitational attraction: A or B?

6. Shout it out!!!
Which objects would have the greatest gravitational attraction: A or B? A A B

7. Shout it out!!!
Which objects would have the greatest gravitational attraction: A or B? A B B

8. Shout it out!!!
Which objects would have the greatest gravitational attraction: A or B? A B B

9. Shout it out!!!
Which objects would have the greatest gravitational attraction: A or B? A B B

10. Shout it out!!!
Which objects would have the greatest gravitational attraction: A or B? A A B

11. Shout it out!!!
Which objects would have the greatest gravitational attraction: A or B? A B B

12. Gravity on the moon is _______ the gravity on Earth.
What we know…
Gravity on the moon is _______ the gravity on Earth.
Greater than
Lesser than
Equal to
The same as

13. Which of the following has the greatest gravitational attraction?
What we know…
Which of the following has the greatest gravitational attraction? A B C

14. Magnets! All magnets have two poles.
Magnets exert forces on each other.
Magnets are surrounded by a magnetic field.

15. The attraction is strongest at the poles.

17. Magnetic Field Lines

18. Magnetic Field Lines

19. Magnetic Field Lines

20. The Earth’s Magnetic Field

21. The Earth’s Magnetic Field

22. Earth’s Magnetic Field Lines

23. Earth’s Magnetic Field Lines

24. Northern Lights

25. Guided Imagery Assignment
Step 1: Fold your paper like a brochure…not in half! Step 2: You need six total squares. Step 3: Listen as the teacher reads different passages. Step 4: Sketch a picture in the box as it appears in your head as you hear the passage being read. Step 5: Repeat this for all six boxes.

26. Box #1
Earth’s magnetic field acts like a giant invisible bubble that shields the planet from the dangerous cosmic radiation spewing from the sun in the form of solar winds.

27. Box #2
The field exists because Earth has a giant ball of iron at its core surrounded by an outer layer of molten metal. Changes in the core’s temperature and Earth’s rotation boil and swirl the liquid metal around in the outer core, creating magnetic field lines.

28. Box #3
The earth’s magnetic field lines look a lot like the magnetic field lines of a simple bar magnet. The earth has its own giant magnet running through its center. Its magnetic south pole is actually up at the earth’s geological north pole.

29. Box #4
Earth’s magnetic field has been weakening since the beginning of The biggest weak spots in the magnetic field have sprung up over the Western Hemisphere. Scientists are unsure why the magnetic field is weakening, but one likely reason is that Earth’s magnetic poles are getting ready to flip.

30. Box #5
Scientists already know that magnetic north shifts. Once every few hundred thousand years the magnetic poles flip so that a compass would point south instead of north. While changes in magnetic field strength are part of this normal flipping cycle, the field is starting to weaken ten times faster than in the past.

31. Box #6
There is no evidence that a weakened magnetic field would result in a doomsday for Earth. During past polarity flips there was no mass extinctions or evidence of radiation damage. Researchers think power grids and communication systems would be most at risk.

32. Back to Bell Work! Look at your KLW chart. Know Learned Want to Know
Fill in the “LEARNED” part about MAGNETS.
What would you like to know?