Space Exploration

Unit E

Key TermsUse the spaces below to define the key terms in your own words.

1.1Key Terms Textbook Definition Drawing / In my own words

Solstice

Equinox

Geocentric

Heliocentric

Ellipses

1.2Key Terms Textbook Definition Drawing / In my own words

Astrolabe

Telescope

Astronomical Unit

Light-year

1.3Key Terms Textbook Definition Drawing / In my own words

Nebulae

Interstellar Matter

Protostar

Sun-like Star

Massive Star

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Main Sequence

Red Giant

Red Supergiant

White Dwarf

Black Dwarf

Supernova

Neutron Star

Black Hole

Constellations

Asterisms

Galaxy

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1.4Key Terms Textbook Definition Drawing / In my own words

Protoplanet Hypothesis

Meteors

Meteoroids

Comets

Asteroids

Meteorites

1.5Key Terms Textbook Definition Drawing / In my own words

Azimuth

Altitude

Zenith

Ecliptic

CHAPTER 1 – HOW HUMAN UNDERSTANDING OF BOTH EARTH AND SPACE HAS CHANGED OVER TIME

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1.1 – EARLY VIEWS ABOUT THE COSMOS

Exploring

The first moon landing by Apollo 11 on July 20, 1969, would not have been possible without many prior ____________________________ advancements.

Increase in ___________________ knowledge gained by the moon missions promoted the development of new _________________________ on Earth for scientific and everyday use.\

Early Views About the Cosmos

Ancient cultures used the regular cycles of the ____________, ____________, stars, constellations and visible planets to mark the passage of ___________. Knowledge was passed on orally or in writing from generation to generation and culture to culture often in the form of legends and folklore.

Finding _________________________ in time was essential in predicting the changing of the seasons and marking important _________________ in peoples’ lives. Ancient peoples used their eyes, calendars and monuments to track important changes. Examples:

lunar cycles scraped on antler Stonehenge - summer solstice Chichen Itza - spring and fall equinoxes Khufu Pyramid - Thuban (former North Star) First Nations medicine circles in Alberta - rising of Sirius

Solstice - Latin sun stop

the ______________________ and ________________________ period of daylight in the year determined by the position of the Sun in the sky

o summer solstice (circa June 21)o winter solstice (circa Dec 21)

Equinox - Latin equal night

the time when day & night are __________________ in ________________ as determined by the Sun being directly over the equator

o spring equinox (circa Mar 21)o fall equinox (circa Sep 22)

Models of Planetary Motion

The first ___________________________ were lunar (Moon). They were accurate enough for nomadic hunters, gatherers and fisherman. The settled societies that followed needed more precise ___________________ (Sun) calendars to predict planting and harvest times.

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Figuring out how the regular motions of the Sun and Moon fit in with the irregular wandering paths of the five known planets was a puzzle that took thousands of years to solve. How the Earth fit into this puzzle was also a mystery.

The Geocentric Model

The Ancient Greek Ptolemy first proposed that the universe was ________________-centered. His conclusion made sense given the knowledge and technology of the time and the everyday experience of people.

Ptolemy thought the Sun and five known planets __________________ the Earth, while the stars were ______________________ in place on a domed ceiling called the celestial sphere.

http://www.youtube.com/watch?v=GmwAr54L_pM

The Heliocentric Model

For thousands of years, math and geometry were the only tools available for studying the universe, but with the development of ______________________ instruments, modern astronomers began to make discoveries that questioned the ___________________ model.

In 1530, Nicholas ____________________________ made observations that led him to conclude that the ______________ was at the center of the universe while the Earth and other planets revolved around the Sun.

In 1610, Galileo ____________________ provided evidence for Copernicus’s hypothesis using a ________________________. Wandering planets made sense if they _____________________ around the Sun along with Earth. He was also able to observe lunar mountains, bumps on Saturn (rings), four moons orbiting Jupiter, sunspots and the phases of Venus.

Observations of planetary motion by Tycho Brahe and mathematical calculations by Johannes _______________________ led Kepler to conclude that planetary orbits were _____________________ instead of circular. The __________________________ model was now fully developed.

An __________________ is oval or egg-shaped.

The Sun is off center from a planet’s orbital path.

Assignment – Pg. 376

1. Define solstice. What are the significant dates associated with the solstices in the northern hemisphere?

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2. What was the ancient monument of Stonehenge believed to be used for?

3. What word is used to describe the times when the length of day equals the length of night? When do these occur?

5. What did the summer and winter solstices indicate to ancient people?

6. Explain the main difference between the heliocentric model of the solar system and the geocentric model.

7. Why was the change from a geocentric model to a heliocentric model considered such a revolutionary idea?

8. Johannes Kepler used hundreds of years’ worth of historical data by many astronomers (notably Tycho Brahe) and his own precise measurements to modify the Copernican model. How did the change proposed by Kepler make the model more realistic?

9. The velocity at which a planet travels does not remain constant throughout its orbit. As it gets closer to the Sun in its orbit, a planet tends to speed up a little. Why do you think this occurs?

1.2 – DISCOVERY THROUGH TECHNOLOGY

Technology has been used for thousands of years to ____________________ time. Examples include:

Sundial merkhet (Ancient Egyptians) to predict star motion quadrant (also Egyptian) to measure star altitude

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astrolabe (Arabs) to chart star positions cross-staff (Gurson 1300s) to measure angle between Moon and stars first optical telescope (1500s)

As lens grinding technology ________________________ and __________________________ became more powerful, it became obvious that distance and size as we know them on Earth are _____________ compared to the scale of space and the objects in it.

Earth is a ______________ planet orbiting an _____________________ star half-way out on one arm of the Milky Way _____________________. The Milky Way itself is but one galaxy in a local ____________________________ of 20 other galaxies surrounded by billions of others.

Distance and Time in Space

The km is too ______________ a unit to measure the vast distances in space. Two units commonly used are the:

1) _______________________________ unit (AU) for local solar system distances

1 AU equals the average ___________________ between the center of the ____________ and center of the __________________

2) ___________________________ for interstellar & intergalactic distances

1 light-year is the distance _________________ travels in a ________________

– because the speed of light is 300 000 km/s in a vacuum, a light year is about 9.5 trillion kilometres

Distance is not the only quantity that is ________________________ in space. Light takes _____________________ to travel between two points, so we are actually looking _______________ in time when observing distant objects in space. Given the small ________________________ on Earth, light appears to ________________________ move from place to place. In fact, it takes light:

– 1 second to reach Earth from the Moon– 8 minutes to reach Earth from the Sun– 5 hours to reach Earth from Pluto– over 4 years to reach Earth from Proxima Centauri, the next closest star– 25 000 years to reach Earth from the Milky Way’s center!

Assignment – Pg. 383

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1. Name three instruments used throughout history to observe the motion of the planets and stars.

2. Explain how a sundial works.

3. What term is used to describe the distance between Earth and the Sun?

4. How far does light travel in one second?

5. Before the development of any technology for observing the sky, how did people map the motion of objects in the night sky?

6. Why were dependable navigation instruments important to the explorers who were crossing oceans to find new lands?

7. How did the telescope change human understanding of space?

8. What is the general relationship between the size of a planet and its distance from the Sun?

1.3 – THE DISTRIBUTION OF MATTER IN SPACE

Much of the visible matter in space makes up _____________ -- hot, glowing spheres of _______________________ gas. The billions and billions of stars vary in:

_____________

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____________________ ____________________________ (colour) ____________________________ (luminosity)

The Hertzsprung-Russell (1920s) diagram ___________________________ stars along a scale based on the properties of __________________________ and _______________________, from white dwarfs and main sequence stars like our Sun, to giants and supergiants like Betelgeuse in the constellation Orion.

Star Life Cycles

The __________ cycle of a star can be compared to the birth, growth and death of a living ___________________.

__________________________ pulls gas and dust in a nebula together into a rotating _________________. The accumulation of more ____________________ in the core causes the temperature to ________________ and possibly start to glow (protostar).

Heating in the ______________ to 10 000 000 0C will cause the ___________________ of hydrogen into helium. A star is born as huge amounts of _________________________ are given off. http://www.youtube.com/watch?v=9EnBBIx6XkM

A star continues to emit radiation for millions or even billions of years. Depending on its ___________, a star can be either:

__________________________ (main sequence in the H-R diagram), or _____________________

A star reaches the end of its life cycle when the supply of ______________________ ___________ runs out.

Sun-like Stars become a ______ ________________ in their second stage as the outer layers expand

and cool become a _____________ ____________________ in their third stage as fusion stops

and the remaining material collapses inward further cooling may create a ______________ _________________

Massive Stars

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o become a red __________________________ in their second stageo __________________ causes them to _________________________ so rapidly in the

third stage that an outgoing shock wave makes the outer layers explode as a __________________________

o supernova remnants form a _____________________ star or ______________ _________

red giant -a relatively cool, large-diameter stage of a Sun-like star

red supergiant - a larger-diameter red giant from an aging massive star

white dwarf - a low-pressure, fusion-less collapsed star with a small diameter black dwarf - the death stage of a Sun-like star supernova - the explosion of a red supergiant following collapse neutron star - a rapidly spinning star remnant black hole - a dense star remnant, so dense it does not allow light to escape

Star Groups

_________________________________ are internationally recognized groupings of stars that seem to _______________ together in the night sky. Cultures have identified human, animal and tool constellations for the purpose of ___________________ the seasons and for religious and story-telling purposes. Example: Ursa Major (Great Bear)

__________________________ are unofficial star groupings. For example, the Big Dipper is an asterism because it is __________ of Ursa Major. Germans call it der Pflug, meaning ‘the plough’.

____________________ are millions of stars combined with gases and dust, all held together by ______________________

Types of Galaxies

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___________________ - Milky Way-style galaxies with long ________________ arms leading away from a bright __________________ core

___________________________ - a disk or football-shaped galaxy made up mostly of _________ stars

____________________________ - smaller galaxy that lacks a definite ________________

http://www.youtube.com/watch?v=zCSSaDPxQls

Assignment – Pg. 391

1. What is the main chemical element in a star?

2. What is the connection between a supernova and a black hole?

3. What is the term used to refer to a group of millions of stars?

4. Explain the Hertzsprung-Russell diagram in your own words.

5. True or false: “Stars exist with every combination of brightness (luminosity) and temperature. No specific patterns exist when star data with these characteristics are plotted.” Explain your answer with reference to the Hertzsprung-Russell diagram.

6. Why are nebulae sometimes referred to as “stellar nurseries”?

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7. Create a word sequence that correctly summarizes the life cycle of massive stars. Use the words: red supergiant, nebula, supernova, massive star, neutron star.

8. Considering the number of stars in space, why don’t astronomers see greater numbers of dwarf stars?

9. Imagine two stars in a galaxy. Both are at the end of their life spans. One star ends up as a white dwarf, the other ends up as a black hole. Describe the conditions that led to these stars having different outcomes.

10. The light we see from the planets in our solar system is just the light reflected from the Sun. Why do planets appear brighter than the vast majority of stars we see?

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1.4 – OUR SOLAR NEIGHBOURHOOD

Sun Facts

100X Earth’s diameter 1 000 000X Earth’s volume 5 500oC surface temperature (_________________) 15 000 000oC core temperature emits ____________ ______________ of charged particles

http://www.youtube.com/watch?v=OmfAyK6CeIg

Planet Facts

The inner planets are ________________ and _________________ (terrestrial)

Mercury, Venus, Earth, Mars

The outer planets are larger and __________________ (Jovian)

Jupiter, Saturn, Uranus, Neptune http://www.youtube.com/watch?v=EsUjHXX-qGs

Other Bodies

____________________ - rocky, metallic bodies between Mars and Jupiter (Van Allen Belt) _______________ - dirty snowballs of dust and ice that orbit another body in the solar system such

as the Sun (e.g. Halley’s comet) meteorites - rocky bodies that __________________ Earth’s surface meteors - (shooting star) do not impact Earth’s surface meteoroids - meteors + meteorites

Assignment – Pg. 400

1. List the names of the inner, or terrestrial, planets.

2. Name three ways in which the outer, or Jovian, planets are alike.

3. Explain the main ways in which the inner planets differ from the outer planets in our solar system.

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Jupiter

4. Describe what an asteroid is.

5. Why are comets sometimes referred to as “dirty snowballs”? Why are their tails visible?

6. What is the name for a meteoroid that survives its journey through our atmosphere and hits Earth?

7. Describe in your own words how the solar system formed.

8. On the upper surface of Jupiter’s atmosphere, the attractive force of gravity is 2.5 times that on Earth. What would a bathroom scale show if a 50 kg person were weighed on Jupiter?

9. For about 20 years, from 1979 to 1999, Pluto was closer to the Sun than Neptune was. Explain why this was possible.

10. Why would it be unreasonable to expect Saturn-like rings around any of the inner planets?

11. Explain how it is possible for an asteroid or a comet to cut directly across Earth’s orbital path but not strike Earth.

12. Suppose a gaseous planet half the size of Saturn were discovered. Where in the solar system do you think it would be located? Give a reason for your answer.

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1.5 – DESCRIBING THE POSITION OF OBJECTS IN SPACE

Our ___________________ point for measuring the position of objects in space is usually the __________________. The two measurements required are:

1) compass direction (__________________) - north would be bearing 00

2) ____________________ above the horizon (maximum is called _________________) - horizon would be 00

http://www.youtube.com/watch?v=LvZx4wgtRPc

The celestial sphere is an ____________________________ dome around the Earth that allows us to describe the __________________________ of an object in space using its azimuth and altitude.

The ____________________________ path of the Sun around this dome is called the ___________________________. The Sun crosses the celestial equator at the fall and spring ___________These are called the _____________equinox and the __________ equinox.

The sun is at 900 to these points at the summer and winter solstices.

Assignment – Pg. 405

1. What name is given to the compass direction when we are trying to locate an object in the night sky?

2. Define altitude.

3. What is the point directly overhead called?

4. Explain what the ecliptic is.

5. Why did the Greeks call the planets “wanderers”?

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6. Why must two coordinates, azimuth and altitude, be given to specify the location of an object in the night sky?

7. The table to the right has two incorrect entries. a) Identify each error and correct it

b) Explain why each of the entries is incorrect.

8. Is it ever possible to specify the location of an object in the sky knowing only the altitude? Explain your answer.

9. 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.

10. a) Does the rotation of Earth affect azimuth and altitude measurements of stars? Explain why or why not.

b) What can be done to ensure someone using your measurements would be able to find the object you located?

Section Review – Pg. 406

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Reading

Azimuth Altitude

1 30° 93°2 364° 45°

2. Define a) astronomical unit and b) light-year

3. What two characteristics of stars are plotted on the Hertzsprung-Russell diagram?

4. What name do we give the nuclear reaction that produces helium from hydrogen?

5. Explain the difference between a constellation and an asterism.

6. Is the Sun likely to become a neutron star? Explain your answer.

7. Imagine that you observe two stars in the night sky. One in as old star and one is a young star. What differences between the two might you observe?

8. What prevents a neutron star from collapsing under its own gravity?

9. What type of galaxy is the Milky Way? Sketch what this type of galaxy looks like.

10. a) In what ways are Mars and Earth similar?

b) In what ways are they different?11. Compare the general characteristics of the inner planets with those of the outer planets.

Feature Inner Planets Outer PlanetsCompositionNumber of moons

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Ring systemsSizeSurface temperature

12. Which planet has surface features that most closely resemble Earth’s? Briefly describe those features.

13. The speed of light is 300 000 km/s. The Sun is about 150 000 000 km from Earth.

a. How long does it take light to get from the Sun to Earth?

b. The distance around Earth at the equator is about 40 000 km. How long would it take light to go around the world once?

14. Explain why distances to stars are not measured in kilometres or astronomical units.

15. Describe the protoplanet hypothesis of how a solar system forms. Use sketches to support your answer.

16. Explain why it is necessary for Earth to have a leap year every four years.

18. The greater the mass of an object, the greater is gravitational attraction. The object with the largest mass in our solar system is the Sun. Because of its large mass, it not only holds the planets in their orbits, but it also attracts great amounts of space debris from the far reaches of the solar system. On occasion, large chunks of debris have even hit Earth, but not as many as astronomers have predicted could hit Earth. What might be some explanations for Earth’s apparent “luck” in not being hit by more space debris?

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