1. Unit 3: To Infinity and Beyond! (Space Exploration)

2. Space Alphabet
In small groups, brainstorm words about space for each letter

3. Topic 1: Our Human understanding of space

4. Built to mark the summer & winter solstices
2300 BC
Neolithic
(Stonehenge)
Built to mark the summer & winter solstices
Sun (as seen from Earth) reaches its:
-Southern (strongest) extreme = longest day
-June 21
-Northern (weakest) extreme = shortest day
-December 21

5. 2000 BC
Aristotle
Geocentric (__________-centered) model
Earth
Stars were attached to outermost sphere
Model could forecast phases of the moon
Model could not predict planetary motion

6. AD
Maya
Chichen Itza
Built to mark the spring and fall Equinox
Length of day & night are equal
March 21 = spring equinox
September 22 = fall equinox

7. 1530 AD
Copernicus
Heliocentric (_________-centered) model
Sun
Able to explain planetary motion

8. 1600 AD Galileo Galilei New technology - telescope
Observations – mountains on moon, “bumps” on Saturn, spots on Sun
Provided evidence to support Copernicus’ theory
Still could not accurately predict planetary motion

9. Orbits of planets were not circular – they were ellipses
1620 AD
Kepler
Orbits of planets were not circular – they were ellipses
Explained planetary motion in Copernicus’ theory

10. Stars A hot, glowing ball of hydrogen gas Gives off light energy
Vary greatly in their characteristics
Mass, density, diameter, and color
Color of a star depends on surface temperature
Hot = blue
Cooler = red

11. Hertzsprung-Russell Diagram
Graph that compares the surface temperature and brightness of stars
Stars fall into distinct groupings

12. Life Stages of a Star How the Universe Works - Disk 1
Episode: Extreme Stars (~26.5min)
0:55-16:48 – nebulae, prostar, main sequence
23:40-29:05 – death of sun-like stars
29:06-34:14 – death of massive stars

13. 1) Nebula
Stars are born in regions of space where there are huge accumulations of gas and dust
Caused by gravitational attraction between atoms of gas and dust
75% hydrogen, 23% helium, 2% oxygen / nitrogen / carbon / silicon dust

14. 2) Prostar
More material is collected
Higher mass
Temperature increases
Starts to glow

15. 3) Main sequence
Fusion
Hydrogen changes to helium
Interior of star gets hotter
Core reaches °C
Releases great quantities of energy and radiation
Stars can be classified as SUN-LIKE or MASSIVE based on their mass

17. 4) Fuel starts to run out
Helium starts to fuse with carbon and other elements
Outer layers starts to expand and star becomes very bright
Turns into:
RED GIANT (sun-like)
RED SUPER-GIANT (massive)

18. 6.2 billion years from now the Sun will have become a red giant star

19. 5) Fusion reaction stops
Core temperature is no longer hot enough to keep reaction going
Sun-like star:
Star becomes WHITE DWARF
Star eventually fades until it is a cold, dark BLACK DWARF

20. Gravity causes core to collapse on itself
Massive star:
Gravity causes core to collapse on itself
Supernova – explosion that marks the death of a massive star
Neutron star – core that is left over; also called black hole
supernova that was first observed around 1050 AD

21. Sun-like star Black Dwarf Nebulae White Dwarf Red Giant Prostar
Supernova
Red Super Giant
Main Sequence
Massive star
Black hole
(neutron star)

23. Star groupings
1. Constellations
Groupings of stars that form patterns
88 official constellations
Ursa Major, Ursa Minor
2. Asterisms
Distinctive star grouping that is not an official constellation
Big Dipper

24. 3. Galaxies
Groupings of millions or billions of stars, gas and dust held together by gravity
Milky Way
Spiral, Elliptical & Irregular galaxies

25. Our Solar Neighborhood
Sun
Sun-like star

26. Solar wind Sun releases charged particles in every direction
Earth is protected by its magnetic field
Results in the Northern lights

27. Planets 2 distinct groups Inner or Terrestrial Outer or Jovian Smaller
Rocky
Close to the Sun
Mercury, Venus, Earth Mars
Outer or Jovian
Larger
Gas giants
Further from the Sun
Jupiter, Saturn, Uranus, Neptune

28. Discovered in 1930
Considered the 9th planet until 2006
Now classified as a dwarf planet

29. Why?
Too far from the sun to be Terrestrial
Too small/rocky to be Jovian
Additional objects have been discovered that are more massive
Has a unique orbit
Is inclined
Intersects with Neptune’s orbit

30. Characteristics of Planets
Smallest?
Largest?
Earth’s sister?
“Red” planet?
Can sustain life?
Volcanoes?
Rings?
Hottest?
Coldest?
400-yr storm?
Closest to sun?
Furthest from sun?

31. Other Bodies Asteroids Small rocky bodies orbiting the Sun
Found mainly in a narrow belt that separates the Terrestrial and Jovian planets

32. Comets
“Dirty snowballs”
Composed of dust and ice
Bright center and long tail
Tail is only visible when comet gets close to Sun
Materials on comet are heated and gases are released

33. Predictable orbits around the Sun
Halley’s Comet – visible every 76 years
First seen in 240 BC, last seen in 1986
Next schedule return is 2062

34. Meteoroids
Small pieces of rocks flying through space with no particular path
Usually only aware of as they pass through our atmosphere
Meteor (shooting star)
Pulled into our atmosphere by gravity
Atmospheric friction causes it to give off light
Meteorite
Hits Earth’s surface

35. Vastness of Distance & Time in Space
What unit would you use to measure the:
Perimeter of your school?
Width of a dime?
Width of your desk?
Distance from Edmonton to Calgary?
Distance from Earth to Mars?

36. Astronomical Unit (AU)
Used for measuring “local” space distances
Inside our solar system
1 AU = km
Average distance from center of Earth to center of the Sun

37. Light Years
Used to measure distances beyond our solar system
Out to stars and galaxies
Light travels km/s
1 light year = 9.5 trillion km (distance light travels in one year)

38. Light from sun/stars doesn’t instantly reach Earth
You are seeing objects as they was at an earlier time
We see the:
Moon as it was ~1 second before
Sun as it was ~8 minutes before
Pluto as it was ~5 hours before
Stars as they were ~ years ago
Astronomers believe the Hubble Telescope has captured images that date back ~12 million years

39. Tracking Celestial Objects
Sundials
Measure the length of day & time
Track the movement of the sun across the sky using shadows

40. Device was aligned with the North Star
Merkhet
Device was aligned with the North Star
Second one was used to establish a N-S line
Used to:
Predict movement of stars/objects
Tell night
The word “merkhet” means “instrument of knowing,”
May have been used in construction of temples and tombs to align structures in particular ways
A merkhet includes a straight bar attached to a plumb line, a weighted line which can be used to establish a straight vertical line to the ground. To use the merkhet, the device was aligned with the North star, and a second merkhet would be used to establish a North-south meridian. This line could be used to align a structure, or as a reference point to track the movement of stars in the sky.
By making note of when particular stars crossed the meridian, the user could determine the time.

41. Used to measure a star’s height above the horizon
Quadrant
Used to measure a star’s height above the horizon
Top right – England, 1388

42. Astrolabe
Accurate charts of star positions

43. Measure the angle between the Moon and any given star
Cross-staff
Measure the angle between the Moon and any given star
To measure the angle between two stars, an astronomer would place the staff just below one eye (drawing) and slide the cross-piece up and down. The cross-piece would have a pair of open sights sticking out perpendicular to the drawing at symmetric locations such as B and B' (often several pairs of sights, some spaced further apart than others). The astronomer would slide the cross-piece up and down, until sight B covered one of the stars and sight B' the other. For use at night, slits make convenient sights (see below).
After that was achieved, the instrument would be lowered and the distance AC would be measured. Then if A was the angle between the staff and the direction of one star, from the definition of the tangent
tanA = BC/AC    The distance BC between the sight and the stick was already known to the astronomer--so, using a table of tangents, the angle denoted by A could be calculated. Since the instrument was symmetric, the angle between the directions of the stars was 2A.

44. Telescope
Increased viewing ability by magnifying light
Able to see objects that are distant
Able to see objects that are faint

45. Position of Objects in Space
How can you accurately find and describe the position of an object in space?
1. How high in the sky is it?
Altitude
Horizon = 0 °
90 ° = straight above you
Zenith

46. 2. In which direction do you look?
Azimuth
Compass direction (360° circle)
Due north = 0°
East = 90°
South = 180°
West = 270°

47. Lab Activity 1: A Star’s Position

48. 8 4 2 3 7 5 1 6
Star  ? ?
Azimuth
75°
315°
285°
20°
Altitude 5°
45°
80°

49. Using Technology to Measure & Interpret Space
Suppose you are sending a probe to investigate Jupiter.
How would you determine the distance to Jupiter to ensure that you have enough fuel?
Triangulation and parallax are 2 ways of measuring distances indirectly

50. Triangulation Measurement based on the geometry of a triangle
Can determine the distance to an object by measuring the angles between a baseline and the target

51. How to measure
1. Measure off an accurate baseline
2. Select your object (opposite the baseline)
3. Stand at one endpoint & determine the inside angle between your sight line and the object
4. Repeat step 3 from the other endpoint
5. Make a scaled drawing
6. Mark a line perpendicular between the baseline and the object
7. Measure the scaled length of the perpendicular line & use scale to convert to real distance

52. Examples Back wall = Earth Front wall = Jupiter Measure off baseline
Length =
Target on Jupiter =
Measure angles from each endpoint
From endpoint A to target:
From endpoint B to target:

53. 1 cm = 1 m

54. What is the scale distance of the baseline?
What is the scale distance to the target?
What is the real length of the baseline?
What is the real distance to the target?

55. 1 cm = 10 AU
9 cm
→ 90 AU A B
13 cm
→ 130 AU

56. 1 cm = 5 light years
11.5 cm
57.5 light years
14.5 cm
72.5 light years

57. How do you view an object from Earth from 2 different angles?
Parallax
The apparent shift in position of object when it is viewed from 2 different places
Astronomers use a star’s parallax to determine what angles to use when triangulating its position

58. The longer the baseline, the more accurate the results
Longest baseline we can use from Earth is the diameter of Earth’s orbit

59. Which are the best endpoints to use to determine the distance from Earth to the unknown star?

60. Determining a Star’s Direction of Motion
Stars are not stationary
How do we measure the distance to an object that is moving?

61. Spectrum of Stars
Way to visualize the different colors of light that are coming from a star
Can break up the light coming from a star by passing it through a spectroscope
Measures how much light is coming at each color

62. The spectra often contain dark lines at particular colors
Means there is much less light coming from the star at that color
Can use the information from these "spectral lines" to figure out what a star is made of
Creates a fingerprint for individual stars

63. Position of dark band in spectrum appear to shift as the star moves towards or away from Earth
Assume Earth is standing still

64. Doppler Effect
The apparent change in the frequency of a wave between an observer and a source as the source moves toward or away from the observer

65. The Doppler Effect allows us to determine if stars are moving towards Earth or away from Earth and at what speed

66. Star is moving toward Earth
Dark bands shift towards BLUE end of spectra
Star is moving away from Earth
Dark bands shift towards RED end of spectra
Amount of shift = speed

67. Spectrum Analysis

72. hydrogen, oxygen, and aluminum
B) carbon, aluminum, and helium
C) carbon, hydrogen, and oxygen
D) oxygen and aluminum

73. Blue light has a higher frequency than red light
Blue light has a higher frequency than red light. A Blue shift represents a celestial light source that is _____ Earth.
A) moving away from
B) moving beside
C) rotating around
D) moving towards