3Tracking Cosmological Events Very special annual events in ancient times were solstices and equinoxes.
4Earth’s Rotation and Seasons Earth’s rotation and the why seasons happen
5SolsticeSolstice – represents the shortest and longest periods of daylightWinter solstice: shortest period of daylightDec. 21st in the Northern HemisphereSummer solstice: longest period of daylightJune 21st in the Northern Hemisphere
6Equinox Equinox – Represents periods of equal day and night Autumnal equinox: occurs in the fallSeptember 22nd in the Northern HemisphereVernal equinox: occurs in the springMarch 21st in the Northern Hemisphere
7Geocentric vs. Heliocentric These two models of how the planets moved in space evolved over time.The role of observation guided scientific understanding of space.
8Geocentric Proposed by Aristotle Assisted by the geometry of Pythagoras and EuclidPlanets revolved around EarthThe stars stayed stationary as if glued to a ceilingThis was agreed upon for about 2000yrs.This model couldn’t explain why some planets seemed to reverse direction (retrograde motion)
9Heliocentric Proposed by Copernicus Later on, Galileo and Kepler determined that the revolution around the sun was an elliptical pattern, not circular.
10EllipsesComplete the QuickLAB on drawing ellipses
14The Astronomer’s Tools Quadrant: Measures a star’s height above the horizonAstrolabe: Measures a star’s angle above the horizon and could predict future star positionsCross-staff: Measures the angle between the moon and any given starTelescope: Allowed scientists to get even closer to the night sky
15The 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)
16The 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.
17Math ProblemAfter 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 lysec min hr day year= 3.97 x 10 km13
18Take a Walk Through the Solar System Outside activity
20What is a star? Hot, glowing ball of gas that gives off light energy Stars vary greatly in their characteristicsThey 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
21Hertzsprung-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.
26InfoBITOur 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).
27What are Black Holes? Black Hole animation Journey to a Black Hole Vsauce
28Star GroupsConstellations – groupings of stars we see as patterns in the night sky.There are 88 recognized constellations by the International Astronomical UnionUnofficially 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.
32Galaxies A grouping of millions or billions of stars, gas, and dust. They are held together by gravityOur galaxy is the Milky WayCan be classified as spiral, elliptical or irregular
331.4 Our Solar Neighbourhood 9 minutes The Solar System: A Brief Glance
34Protoplanet Hypothesis The theory of how solar systems are formed
35The Sun Made up of mainly Hydrogen and Helium 110 times wider than EarthSurface temperature = 5500ºCCore temperature = ºCReleases a steady flow ofcharged particles that flowout in every direction, thisis called solar wind.
37The 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 sunOuter – large and gaseous, far away from sun
39Organize significant information on the Planet Information Sheet Bill NyeThe Planets
40Why Do Planets Move in an Orbit? Answer: Universal GravitationExplanation: 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.
41Other Bodies in the Solar System AsteroidsBetween 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 kilometersOrigin of asteroids: scientists are uncertain
42Other Bodies in the Solar System CometsMade of dust and ice that travels through spaceWhen 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.
43Other Bodies in the Solar System MeteoroidsSmall pieces of rock flying through spaceMeteorWhen a meteoroid is pulled into our atmosphere, atmospheric friction causes it to light upThese are shooting starsMeteoriteIf the meteor lasts long enough to hit earth, it is called a meteoriteTwo impact cratersleft by a meteoritein Quebec
451.5 Describing the Position of Objects in Space Intro to Solar Orientation [Solar Schoolhouse]
46Where 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.
47Altitude Altitude gives you the “how far above the horizon it is”. Stars straight up will be at 90ºPoints on the horizon will be at 0ºStars half way up the skywill be at 45ºZenith refers to thehighest point directlyoverhead
48AzimuthAzimuth determines which compass direction it can be found at in the sky.Stars in the north will have an azimuth of 0ºEast = 90ºSouth = 180ºWest = 270º
50Determining the Motion of Objects in Space Planet means “wanderer” in ancient GreekRead page 404 in Science In Action 9Celestial equator is directlyabove the Earth’s Equator
51Using the InformationBecause 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
52Solar Eclipse When the moon passes between the Sun and the earth. A shadow is cast on the earth.
53Lunar Eclipse When the earth passes between the moon and the sun. A shadow is cast on the moon.
54PAT Style QuestionsUse 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 centeredSun centeredProposed in the 1500sProposed 2000 years agoProposed by AristotleProposed by CopernicusThe notes above related to the “heliocentric” model of planetary motion are labeledA C FB C FA D EB C E
55PAT Style QuestionsThroughout time, people have created stories and proposed theories about space. The aboriginal people are knon for their legends that dealt withDescriptions of planetsThe formation of star constellationsPredictions about cometsExplanations of star travel
56PAT Style QuestionsUse 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 motionNumerical ResponseListed from the earliest contribution to the most recent contribution, the order is ______, _______, _______, and _______
57PAT Style QuestionsUse the following information to answer the next question.Four characteristics of a certain type of star are given below.Contain extremely high-density materialsHas a strong gravitational pullLight cannot escape from its pull of gravityDifficult to detectThe type of star that these characteristics describe is aWhite dwarfNebulaBlack holeSupernova
58PAT Style QuestionsUse the following information to answer the next question.I The formation of stars is called constellationII Stars start out as an accumulation of dust and gases called a nebulaIII The Milky Way is another name for an exploding starIV Galaxies can be classified as spiral, elliptical, or irregularNumerical ResponsePlace the number 1 in the blank if the statement is true and the number 2 if it is false._______ _______ _______ _______I II III IV
59PAT Style QuestionsUse 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 StarNebulaeSupernovaRed GiantListed in order from the earliest stage in a star’s life to the last stage, the stages are ______, ______, ______, ______
60PAT Style QuestionsThe second largest planet with rings in our solar system isUranusJupiterSaturnNeptune
61PAT Style QuestionsUse 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 ResponseIn 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) __________________
62PAT Style QuestionsA 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 sunEarth was between the moon and the sun, but the moon was lower and the sun was higher.
63PAT Style QuestionsJen 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 actuallyThe tail end of a cometA cluster of brightly lit starsMany meteors entering the atmosphereAn explosion of a supernova
64Review QuestionsWhat 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?