1. Earth from the Perspective of Space
Earth Science Notes
Earth from the Perspective of Space

2. Objectives
I can…
Describe Earth’s place in the solar system, galaxy, and universe.
Explain the effect that Earth’s tilt and orbital position have.
Describes Earth’s orbital variations.
Differentiate between solstices and equinoxes and explain what causes them.

3. Earth from Space
If you could see the earth illuminated when you were in a place as dark as night, it would look to you more splendid than the moon.
— Galileo Galilei, Dialogue Concerning the Two Chief World Systems, 1632.
How might looking at Earth from the perspective of space change the way we think?  Write a response on the next slide.

4. How might looking at Earth from the perspective of space change the way we think?
Your Response:

5. Astronauts view of the Earth in their own Words
”I didn’t feel like a giant. I felt very, very small.”
- Neil Armstrong on looking back at the Earth from the Moon in July 1969.
When you're finally up at the moon looking back on earth, all those differences and nationalistic traits are pretty well going to blend, and you're going to get a concept that maybe this really is one world and why can't we learn to live together like decent people.
— Frank Borman, Apollo 8
To look out at this kind of creation out here and not believe in God is to me impossible, ...
- John Glen, Mercury and Atlas Astronaut
Oddly enough the overriding sensation I got looking at the earth was, my god that little thing is so fragile out there.
— Mike Collins, Apollo 11 astronaut

6. Where Earth is in the Universe: Solar System

8. Where Earth is in the Universe: Galaxy

9. Where Earth is in the Universe: Universe
The Milky Way Galaxy

10. Where Earth is in the Universe

11. What Earth is doing as it moves through Space
Our Sun (and solar system) revolves around the black hole that is in the center of our galaxy

12. What Earth is doing as it moves through Space
As our sun revolves around the center of our galaxy, the Earth revolves around our sun.

13. What Earth is doing as it moves through Space
The Earth travels around the sun on an oscillating ellipse.

14. What Earth is doing as it moves through Space
Misconception: We experience winter when Earth gets farther from the sun and summer when Earth gets closer to the sun. What does the model below say?

15. What Earth is doing as it moves through Space
As Earth revolves it is tilted on its axis by 23.5°.
This tilt is what is responsible for the seasons.
The axis of rotation points toward the north star Polaris.

16. What Earth is doing as it moves through Space
We can see how Earth is spinning on its axis by examining how the stars in the sky revolve around the north star (Polaris).

17. What Earth is doing as it moves through Space
At different points in its revolution, Earth’s hemispheres point toward or away from the sun. Toward = summer Away = Winter

18. What Earth is doing as it moves through Space
When the NH is tilted toward the sun it receives more direct sunlight, therefore, we experience summer. When the NH is tilted away the sunlight we receive is less intense because the same amount of light is spread over a larger area of the Earth. This doesn’t heat as well.

19. What Earth is doing as it moves through Space
Notice:
The middle latitudes only get intense sunlight for their summer months.
The latitudes near the equator always have some intense sunlight.
What about the Artic and Antarctic?

20. What Earth is doing as it moves through Space
Due to the Earth’s tilt and the position of Earth in its orbit, the sun appears to take different tracks across the sky during the course of a Year.

21. What Earth is doing as it moves through Space
During the Summer Solstice (June 21st) – the day in Earth’s revolution where its axial tilt is most inclined to the sun.
The sun is the furthest north of the equator – directly over the tropic of Cancer.
On this day the sun appears the farthest north in the sky and also appears higher in the sky than at any other day of the year.

22. What Earth is doing as it moves through Space
During the Winter Solstice (December 21st) – the day in Earth’s revolution where its axial tilt is pointed away from the sun (in NH).
The sun is the furthest South of the equator – directly over the tropic of Capricorn.
On this day the sun appears the farthest SOUTH in the sky and also appears LOWER in the sky than at any other day of the year.

23. What Earth is doing as it moves through Space
During the Equinoxes the Sun is directly over the equator.
This means equal amounts of sunlight/daylight for the North and South Hemispheres.

24. What Earth is doing as it moves through Space
Comparison of the Sun’s path in the sky during solstice and equinoxes.

25. Historically, solstices and equinoxes have meant a lot to mankind.
Vikings visited wells and made monetary sacrifices (money) during the summer solstice.
Wyoming’s Bighorn medicine wheel, an arrangement of stones built several hundred years ago by the Plains Indians, aligns with the solstice sunrise and sunset, and was the site of that culture’s annual sun dance.
Druids gathered at Stonehenge for the summer solstice, winter solstice, spring equinox and autumn equinox.

27. Summary
Can I…
Describe Earth’s place in the solar system, galaxy, and universe.
Explain the effect that Earth’s tilt and orbital position have.
Describes Earth’s orbital variations.
Differentiate between solstices and equinoxes and explain what causes them.