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Human Understanding of both Earth and Space has Changed Over Time

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Presentation on theme: "Human Understanding of both Earth and Space has Changed Over Time"— Presentation transcript:

1 Human Understanding of both Earth and Space has Changed Over Time
Unit E: Topic One

2 1.1 Early Views About the Cosmos

3 Tracking Cosmological Events
Very special annual events in ancient times were solstices and equinoxes.

4 Earth’s Rotation and Seasons
Earth’s rotation and the why seasons happen

5 Solstice Solstice – represents the shortest and longest periods of daylight Winter solstice: shortest period of daylight Dec. 21st in the Northern Hemisphere Summer solstice: longest period of daylight June 21st in the Northern Hemisphere

6 Equinox Equinox – Represents periods of equal day and night
Autumnal equinox: occurs in the fall September 22nd in the Northern Hemisphere Vernal equinox: occurs in the spring March 21st in the Northern Hemisphere

7 Geocentric vs. Heliocentric
These two models of how the planets moved in space evolved over time. The role of observation guided scientific understanding of space.

8 Geocentric Proposed by Aristotle
Assisted by the geometry of Pythagoras and Euclid Planets revolved around Earth The stars stayed stationary as if glued to a ceiling This was agreed upon for about 2000yrs. This model couldn’t explain why some planets seemed to reverse direction (retrograde motion)

9 Heliocentric Proposed by Copernicus
Later on, Galileo and Kepler determined that the revolution around the sun was an elliptical pattern, not circular.

10 Ellipses Complete the QuickLAB on drawing ellipses


12 Bill Nye Outer Space

13 1.2 Discovery Through Technology

14 The Astronomer’s Tools
Quadrant: Measures a star’s height above the horizon Astrolabe: Measures a star’s angle above the horizon and could predict future star positions Cross-staff: Measures the angle between the moon and any given star Telescope: Allowed scientists to get even closer to the night sky

15 The Immensity of Distance and Time in Space
1. Astronomical Unit (AU) is used for measuring distances inside our solar system (aka “local distances”) 1 AU = km (the distance from the center of the Earth to the center of the sun)

16 The Immensity of Distance and Time in Space
2. Light-Year (LY) is used for distances beyond the solar system, out to stars and galaxies. LY = 300,000 km/sec (the distance light travels in one second) Keep in mind that a light year is a distance, not a time. If you wanted to wind a piece of string 1 light-year long, you would have enough string to wrap it around 236 million times.

17 Math Problem After the sun, the next nearest star to Earth, Alpha Centauri, is 4.2 light-years away. How many kilometers is this? Answer: 300,000km x 60 sec x 60 min x 24 hr x 365 days x 4.2 ly sec min hr day year = 3.97 x 10 km 13

18 Take a Walk Through the Solar System
Outside activity

19 1.3 The Distribution of Matter in Space

20 What is a star? Hot, glowing ball of gas that gives off light energy
Stars vary greatly in their characteristics They can be compared by their surface temperature and their brightness (luminosity) Our sun has a mass 300,000 times greater than earth. See next picture

21 Hertzsprung-Russel Diagram
In the 1920s, two scientists, Ejnar Hertzsprung and Henry Norris Russel, began comparing the surface temperature of stars with the stars’ brightness (luminosity). When they plotted their data, they discovered that the distribution of star temperature and brightness is not random. Instead, the “Hertzsprung-Russel diagram” shows the stars fall into several distinct groupings. Part of this pattern has since been accounted for by the current theory of how stars evolve and change over very long periods of time.


23 The Birth of a Star

24 Watch it!

25 Draw the picture in your notes

26 InfoBIT Our sun is a very average star in the middle part of its life. How average is it? Stand 1 m away from the wall. This distance represents the Sun’s diameter. At this scale, the diameter of the largest star now known would be 2300m (2.3 km).

27 What are Black Holes? Black Hole animation Journey to a Black Hole

28 Star Groups Constellations – groupings of stars we see as patterns in the night sky. There are 88 recognized constellations by the International Astronomical Union Unofficially recognized groupings are called asterisms. The most common asterism is the big dipper – it is part of the constellation Ursa Major but it is not a constellation itself.

29 The Universe: The Constellations



32 Galaxies A grouping of millions or billions of stars, gas, and dust.
They are held together by gravity Our galaxy is the Milky Way Can be classified as spiral, elliptical or irregular

33 1.4 Our Solar Neighbourhood
9 minutes The Solar System: A Brief Glance

34 Protoplanet Hypothesis
The theory of how solar systems are formed

35 The Sun Made up of mainly Hydrogen and Helium
110 times wider than Earth Surface temperature = 5500ºC Core temperature = ºC Releases a steady flow of charged particles that flow out in every direction, this is called solar wind.

36 Bill Nye The Sun

37 The Planets Each has its own unique features and characteristics.
Divided into inner planets (terrestrial) and outer planets (Jovian). Inner – tend to be smaller and rockier, close to sun Outer – large and gaseous, far away from sun

38 songs Elatedwhy pluto is no longer a planet

39 Organize significant information on the Planet Information Sheet
Bill Nye The Planets

40 Why Do Planets Move in an Orbit?
Answer: Universal Gravitation Explanation: There is a gravitational force between all objects that pulls them together. When no forces act on an object, it will move in a straight line at a constant speed. Since the sun has gravity to pull the planets inwards, they move in an elliptical orbit.

41 Other Bodies in the Solar System
Asteroids Between the orbits of Mars and Jupiter lies a narrow belt of small, rocky or metallic bodies traveling in space. They range in size from a few meters to hundreds of kilometers Origin of asteroids: scientists are uncertain

42 Other Bodies in the Solar System
Comets Made of dust and ice that travels through space When they get close to the sun, they heat up and gases are released. As the comets move, the streaming gases are visible as a “tail” Comets usually stay in the outer edges of the solar system, but sometimes they’re thrown into the inner solar system and regularly rotate around the sun.

43 Other Bodies in the Solar System
Meteoroids Small pieces of rock flying through space Meteor When a meteoroid is pulled into our atmosphere, atmospheric friction causes it to light up These are shooting stars Meteorite If the meteor lasts long enough to hit earth, it is called a meteorite Two impact craters left by a meteorite in Quebec

44 Bill Nye Comets and Meteors

45 1.5 Describing the Position of Objects in Space
Intro to Solar Orientation [Solar Schoolhouse]

46 Where in the sky is it? In history, how did they measure locations of celestial bodies in the sky? In order for scientists to understand the sky and what was going on, they had to observe, measure and calculate. To document the location of an object, scientists use altitude, azimuth and altitude-azimuth coordinates.

47 Altitude Altitude gives you the “how far above the horizon it is”.
Stars straight up will be at 90º Points on the horizon will be at 0º Stars half way up the sky will be at 45º Zenith refers to the highest point directly overhead

48 Azimuth Azimuth determines which compass direction it can be found at in the sky. Stars in the north will have an azimuth of 0º East = 90º South = 180º West = 270º

49 Estimating Positions in Space

50 Determining the Motion of Objects in Space
Planet means “wanderer” in ancient Greek Read page 404 in Science In Action 9 Celestial equator is directly above the Earth’s Equator

51 Using the Information Because astronomers understand the nature and geometry of elliptical orbits, as well as of celestial motion, they now understand the paths of planets and their moons. This allows the timing of solar and lunar eclipses to be predicted. Some enthusiasts make it a hobby to plan trips wherever they can around the world to witness eclipses

52 Solar Eclipse When the moon passes between the Sun and the earth.
A shadow is cast on the earth.

53 Lunar Eclipse When the earth passes between the moon and the sun.
A shadow is cast on the moon.

54 PAT Style Questions Use the following information to answer the next question. Any was given a list of notes on early theories of celestial bodies (sun, moon, and planets) Earth centered Sun centered Proposed in the 1500s Proposed 2000 years ago Proposed by Aristotle Proposed by Copernicus The notes above related to the “heliocentric” model of planetary motion are labeled A C F B C F A D E B C E

55 PAT Style Questions Throughout time, people have created stories and proposed theories about space. The aboriginal people are knon for their legends that dealt with Descriptions of planets The formation of star constellations Predictions about comets Explanations of star travel

56 PAT Style Questions Use the following information to answer the next question. Four scientists and their contribution to the study of space are listed below. Kepler proposed that the planets revolve around the sun in an elliptical orbit. Aristotle proposed that Earth is in the center and all the planets revolve around the Earth. Galileo used the telescope to confirm the sun-centered model of planetary motion. Copernicus proposed the “heliocentric” model of planetary motion Numerical Response Listed from the earliest contribution to the most recent contribution, the order is ______, _______, _______, and _______

57 PAT Style Questions Use the following information to answer the next question. Four characteristics of a certain type of star are given below. Contain extremely high-density materials Has a strong gravitational pull Light cannot escape from its pull of gravity Difficult to detect The type of star that these characteristics describe is a White dwarf Nebula Black hole Supernova

58 PAT Style Questions Use the following information to answer the next question. I The formation of stars is called constellation II Stars start out as an accumulation of dust and gases called a nebula III The Milky Way is another name for an exploding star IV Galaxies can be classified as spiral, elliptical, or irregular Numerical Response Place the number 1 in the blank if the statement is true and the number 2 if it is false. _______ _______ _______ _______ I II III IV

59 PAT Style Questions Use the following information to answer the next question. A star is a burning ball of gases that has different stages in its life cycle. Four of these stages are given below. Neutron Star Nebulae Supernova Red Giant Listed in order from the earliest stage in a star’s life to the last stage, the stages are ______, ______, ______, ______

60 PAT Style Questions The second largest planet with rings in our solar system is Uranus Jupiter Saturn Neptune

61 PAT Style Questions Use the following information to answer the next question. Calvin is setting up a model of the solar system. He positions a cardboard sun at one end of a school hallway and Pluto at the other end, 20m away. Calvin knows that Pluto is 39.5 AU (astronomical units) from the sun and Jupiter is 5.27 AU from the sun. Numerical Response In order to make this model to scale, how many meters from the cardboard sun should Calvin place Jupiter? (Record your answer to two decimal places) __________________

62 PAT Style Questions A total solar eclipse was observed across the Antarctic on November 23, This meant that the sun, Earth, and moon were in what alignment? The sun was between Earth and the moon. The moon was between the sun and Earth. Earth was between the moon and the sun Earth was between the moon and the sun, but the moon was lower and the sun was higher.

63 PAT Style Questions Jen read in an astronomy book that every 33 years, Earth passes through the Leonid stream resulting in a shower of “shooting stars” visible on earth. This shower is actually The tail end of a comet A cluster of brightly lit stars Many meteors entering the atmosphere An explosion of a supernova

64 Review Questions What name is given to the compass direction when we are trying to locate an object in the night sky? Define altitude. What is the point directly overhead called? Explain what the ecliptic is. Why did the Greeks call the planets wanderers? Why must two coordinates, azimuth and altitude, be given to specify the location of an object in the night sky? The table below has two incorrect entries. Identify each error and correct it to something possible. Explain why each of the two entries is incorrect. Is it ever possible to specify the location of an object in the sky knowing only the altitude? Explain your answer. Imagine two friends, one in Calgary and the other in Edmonton, observing the same body in space. Describe how their coordinates would be different for the same object. Does the rotation of the Earth affect azimuth and altitude measurements of the stars? Explain why or why not. What can be done to ensure someone using your measurements would be able to find the object you located?


66 Topic 1 Quiz Date:

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