1. Space exploration

2. early views about the cosmos

3. Special cosmological events
Humans have always looked up to the night sky in wonder- looking at planets and stars and the moon- and wondering how it all worked together
Early civilizations such as the Mayans and Egyptians built monuments to honour the seasonal position of stars

4. Other Cultural Events with Space
Myths, folklore and legends were used to explain what ancient people observed in the night sky.
• Ancient African cultures set large rock pillars into patterns to predict the timing of the solstices as well.
• First Nations people of the Pacific Northwest - believed the night sky was a pattern on a great blanket overhead, which was held up by a spinning 'world pole' resting on the chest of a woman named Stone Ribs.
• The Mayans of Central America built an enormous cylinder shaped tower, at Chichen. Itza, to celebrate the two equinoxes.
• The Ancient Egyptians built many pyramids and other monuments to align with the seasonal position of certain stars.
• Inuit in the high Arctic - used a mitt to determine when seal pups would be born, by holding the mitt at arm's length at the horizon.
• Aboriginal Peoples of Southwestern Alberta used key rocks, which aligned with certain stars, in their medicine circles.Ancient cultures tried to explain the motions of the stars and planets.
• The Ancient Celts set up megaliths, in concentric circles, at Stonehenge to mark the winter and summer solstices.

5. 2 special annual events are called solstices
1) Summer Solstice- the longest day of the year
June 21
2) Winter Solstice- the shortest day of the year
December 21
Why might people have been interested in tracking these things?

6. Another special phenomenon is called the equinox which occurs in spring and fall
The equinox is when the length of the day and night are the same

7. Models of planetary Motion
1) Geocentric Model
Aristotle, 2000 years ago, created the Earth-centered model where he believed everything revolved around the Earth.
How many things actually revolve around the earth?
There were many things the model could not explain

8. Geocentric Model Issue
How could it be true that Mars, Jupiter and Saturn orbited around the Earth when sometimes they looped in the sky?

9. 2) Heliocentric Model
In 1530 Nicholas Copernicus proposed the heliocentric model which stated that the Earth and other planets revolved around the Sun
This model explained many of the issues that there were with the geocentric model

10. Let’s Compare them Both

11. Think about it
Why would previous views of space matter to what we know of today?

12. Definitions Orbit- a celestial body’s path Ellipse- oval shape
What does the Earth orbit around?
What does the moon orbit around?
What does the sun orbit around?
Ellipse- oval shape

13. Think about it
When planets move in ellipses their speed does not remain constant- the closer they are to the “narrow part” of the ellipses the faster they move
Their temperature varies also as they move closer and further from the sun
Do you expect the earths orbit to be more elliptical or circular?
Why?

14. The Distribution of Matter in Space

15. I Can…
Describe the different forms of matter in space (e.g., stars, star systems, galaxies, Nebulae)

16. What is a Star?
Stars are glowing balls of gas that are made mostly of hydrogen
They can vary in the colour that they give off, their size and their density
Hotter stars look blue and cooler stars look red

17. Ejnar Hertzsprung and Henry Norris Russell compared stars surface temperature to their brightness (luminosity)
They discovered that there is a link between temperatures and brightness of stars
This is called the Hertzsprung-Russell Diagram

18. Let’s Draw!! Copy out the pictures on page 385 into your notes
Be sure to include the axis and stars names
Supergiants
Giants
Sun
White Dwarf
Main Sequence

19. The Birth of a Star
Stars form in a region of spaced called a nebula (made of hydrogen, helium, oxygen, nitrogen and carbon)
This matter is called interstellar matter and came from exploded stars

20. Example: Crab Nebula
Notice how much matter there is in the nebula

21. Steps of a Star’s Birth
1) Some of the material in the nebula can collapse into a rotating cloud of dust and gas
2) The temperature climbs
3) If it gets hot enough it will glow
4) The is called a protostar- first stage in a star’s formation

22. The Life and Death of a Star
The new star may become Sun-like or massive
These stars convert hydrogen to helium in their core (nuclear reactors)
These stars can remain stable for millions of years (or so they think)

23. When the hydrogen runs out the star’s gravity pulls in the other matter and can turn into a red giant (if it is a sun-like star) or a supergiant (if it is a massive star)
Eventually the reaction in the red giant star quits, the star shrinks becoming a white dwarf and then a cool dark black dwarf

24. The massive star explodes when it runs out of fuel and goes through a supernova
From there is can turn into a neutron star or a black hole
A black hole is a very dense remnant of a star with gravity so strong that light can’t escape from it

25. Black Holes Black holes are invisible to telescopes
Black holes were discovered because of how materials react near them

26. Draw Again!
Copy the diagram on page 386 into your notes to help you keep track of the life of a star

27. Star Groups AKA Constellations
Constellations are groupings of stars that we see in the sky
Early civilizations drew pictures in the stars and named them constellations

28. Galaxies
A galaxy is a grouping of millions of stars, gas and dust which is held together by gravity
Our galaxy is called the Milky Way– it is a spiral galaxy which looks like a CD with a marble in the middle
Other galaxy shapes are elliptical and irregular

29. Elliptical Galaxy

30. Irregular Galaxy- No Specific Shape

31. Our Solar Neighbourhood

32. I Can…
Identify evidence for, and describe characteristics of the planets and compare these to Earth

33. The Sun The Sun is the center of our solar system
The Sun is almost a million times bigger than earth
Its surface temperature is 5500 degrees and the core is degrees
The sun gives off charged particles- it is called solar wind and travels 400km/s
We are protected by our magnetic field

35. The Planets The planets are very different from one another
They are divided into two groups
Terrestrial: earth-like and rocky nearer to the sun
Jovian (gaseous)- large and made of gases, further from the Sun

36. Terrestrial Planets
Mercury, Venus, Earth, and Mars

37. Jovian Planets
Jupiter, Saturn, Uranus, and Neptune

38. Just For Fun

39. Other Bodies in the Solar System
Asteroids- small rocky or metallic bodies that travel in space
Can be a few meters to several hundred km across
Can we stop an asteroid?

40. Comets- described as “dirty snowballs” made up of dust and ice that travel through space.
They tails can be seen when they get closer to the Sun

41. Meteoroids – a rock in space, no particular gravitational path
Meteors – rock from space pulled into earth’s gravitational pull
Meteorites – space rock falling towards earth’s surface
Are small pieces of rocks flying through space from as small as a grain of sand to as large as a car
When it gives off light it is called a meteor or a shooting star

42. Describing the Position of Objects in Space

43. I can…
Describe and apply techniques for determining the position and motion of objects in space (relative position - altitude and azimuth), (elliptical orbits - string on 2 pivot points), (distances - triangulation).

44. Tracking Objects in the Solar System
Eclipses occur when one celestial body moves in front of another one
Because we understand orbits we can predict eclipses

45. Locating Objects in Space
There are 2 different measurements that we need in order to pinpoint an object in the sky and communicate where it is to other people
Think of the sky like a bowl, how could you tell someone where a dot was on the inside of the bowl?

46. Azimuth
The first measurement we use is called the azimuth, it tells us what direction to face.
The direction for azimuths are similar to the directions on a compass
Note: on a compass there is a north/south line dividing the compass
What is the north/south line in Lethbridge?
System one- North, East, South, West
System two- degree 0-North, 90-East, 180-South, 270-West

47. ALTITUDE
The other measurement is called altitude and it tells you how high up to look from the horizon
If it was exactly on the horizon it would be 0 degrees
If you were looking straight up then it would be 90 degrees
What numbers can be used for altitude?

48. Zenith
The highest point in the sky is called the zenith.

49. Let’s check it out!

50. Clinometer Use
Practice: Make and use a clinometer to measure the angle of height for objects in the room

51. Think about it! Observation Point
Why would it matter where the observer is when they are given azimuth- altitude measurements to find a specific planet?

52. Video

53. Determining the Motion of Objects in Space
Stars appear to stay in one place in the sky because they are so far away from us
Planets move in relation to the stars fairly quickly (we can see changes in days or weeks)
The path in with the Sun moves in the sky is called the ecliptic
Check out the diagram on page 404 to see the “celestial sphere”