(PDF) Close, Far Away, - Nelsonlearningcentre.nelson.com/student/9780070988507/...have less inﬂuence. If the Sun were to suddenly disappear, its mass would vanish, and its gravitational

170 MHR • Unit 3 Space
C H A P T E RC H A P T E R
Can you find Earth on this diagram?
You have learned how technology has helped people explorefurtherinto space. As technology improves, it has allowed us tolearn moreabout space and discover new and exciting objects.The space aroundEarth is filled with stars, planets, moons, andother objects suchas comets and asteroids. How far away arethey? What does Earth havein common with them? How isEarth different? How big is space?
Earth belongs to a group of objects that are in a space thatisbigger than you can imagine. We are going to find out whatexistsnear us in space.
Close, Far Away,Close, Far Away,• How close is Earth
to other objects inspace?
• What keeps the solarsystem together?
• What types of objectsare there in space?
Chapter 6 Close, Far Away, and Really Far Away • MHR 171
What You Will Learn
In this chapter, you will learn
• that our solar system is very large• that there are differenttypes of planets in
our solar system
• that gravity keeps the solar system together
Why It Is Important
• Learning about objects in space can helpus learn more aboutevents on Earth and inthe universe.
• Techniques developed for space explorationcan be applied toother scientific studies.
Skills You Will Use
In this chapter, you will
• investigate a mystery planet • design and construct models ofspace
technology
• interpret data about planets
Starting Point
What Happened to the Moon?
and Really Far Awayand Really Far Away6–A
The surface of the Moon is not smooth. Lookthrough binoculars,and you can see it isactually covered with craters. How do youthinkthe Moon ended up with these craters?
Materials
all purpose flour dry tempera paint or aluminum pan powdereddrink mixball bearing golf ball
What to Do
1. Working in groups, spread a layer offlour over the base ofthe pan. Sprinklethe dry tempera paint on top of the flour.
2. Spread newspaper on the floor, andplace the pan on top of thenewspaper.
3. From various heights (standing on thefloor, then on a chair),drop a ballbearing or golf ball into the pan. Whatdo you see?Record your observations.
4. Each time you drop a ball, you must fixyour “moon surface”and reapply thedry paint or drink mix powder.
What Did You Find Out?
1. Do the marks in your tray left by thedropping balls resemblethe craters onthe Moon? How do they look the same?
2. How did the height of the drop of the ballaffect the size andshape of the crater?
3. How do you think the Moon received its craters?
Why do you think there are no livingorganisms on the Moon?
Inside the Solar SystemFor many centuries people have observedobjects other than theMoon moving in the night sky. They noticedthat some of thesebright, star-like objects changed position fromnight to night.Over the course of about 200 years, people began tounderstandwhat was happening. Nicolas Copernicus described howtheplanets circled the Sun in their own orbits. With theinventionof the telescope, Galileo Galilei discovered that thebrightobjects were other worlds, different from the stars, withtheirown features and moons. Johannes Kepler figured out the lawsofplanetary motion, and Isaac Newton explained the physicsbehindKepler’s laws. Together these men and others concludedthat theseplanets, Earth, asteroids, dust, gases, and other objectsthat orbitthe Sun form our .
The Size of the Solar System When looking at diagrams of thesolar system, such as Figure 6.1,it is easy to imagine that it isnot very big. In order to fit all ofthe solar system on one page,artists must create sketches thatdramatically change both size anddistance within the solar system.In the next activity, you will bediscovering just how big oursolar system really is.
solar system
172 MHR • Unit 3 Space
Section 6.1
C H A P T E R 5C H A P T E R 6
solar system
moon
Key Terms
Figure 6.1 Howmany major planetsare there in thesolarsystem?
SunMercuryMercury
VenusVenusEarthEarth
MarsMars
Jupiter
Saturn
UranusUranusNeptune
The Solar SystemThe Solar System
Chapter 6 Close, Far Away, and Really Far Away • MHR 173
Find Out ACTIVITY
Scaling the Solar System
6–B
Maximum Distance from Planet Name the Sun (millions of km)
Mercury 70
Venus 109
Earth 152
Mars 249
Jupiter 816
Saturn 1507
Uranus 3004
Neptune 4537
Distance of Planets from the Sun
Find out what planets are in our solar systemand where they arein relation to Earth.
What You Need
chart paper metre stick(s)markers scissorstape calculator
Safety Precautions
• Take care using scissors.
What to Do
1. Working in groups or with a partner, cutout eight golfball-sized circles of paper.
2. Label each circle as one of the planets:Mercury, Venus,Earth, Mars, Jupiter,Saturn, Uranus, and Neptune.
3. Place the chart paper lengthwise infront of you. In thecentre of the leftedge, draw and label the Sun.
4. In order to figure out where the planetsare in relation tothe Sun, you need todo some calculations. Here is a chartof thedistance between the planetsand the Sun:
5. Since these distances are so massive,you need to have a scalethat representsthese distances so you can fit them onthe paper. Thescale you are going touse is 1 cm � 100 000 000 km. Tomake yourcalculations easier, you cantake each of the abbreviateddistancesin the chart, and divide them by 100.(e.g., Mercury: 70 �100 � 0.7 cm)
6. Now take your metre stick and measure0.7 cm from the Sun.Tape Mercury tothis spot on your chart paper.
7. Continue your calculations and mea-suring until all of theplanets have beentaped to the paper.
8. Be sure to include the scale on yourchart.
What Did You Find Out?
1. Explain why you think is it important to have a scale whenmapping thesolar system.
2. If it takes a spacecraft three months toget to Mars, how longmight it take toreach Jupiter?
3. Why do you think it is hard for peopleto sometimes understandjust how bigthe solar system is?
Gravity and Orbits So what keeps all these planets in one solarsystem, orbitingaround the Sun? The answer is gravity. As you know,gravity isa force that pulls together any two objects that havemass (theamount of matter in an object). The strength of thegravitationalattraction between two objects depends on the massesof theobjects. It also depends inversely on the distance betweenthem.This means that the gravitational force between two massesgetslarger as the masses get larger. It also means that as thedistancebetween two masses gets larger, their gravitationalattraction getssmaller.
Now, think of all the objects in the solar system: theSun,planets, moons, asteroids, and other objects. All of theseobjectshave mass. The Sun has the largest mass and therefore tendstodominate or control the orbital motion of all the planetsandother objects in the solar system. The other objects in thesolarsystem have much smaller masses than the Sun and thereforehaveless influence. If the Sun were to suddenly disappear, itsmasswould vanish, and its gravitational field would disappear.As aresult, each planet and solar system object would “fly” offintospace in a straight line.
Figure 6.2 The gravitational force of the Sun keeps Earth andall of the otherplanets in their orbits. If you could turngravityoff, Earth would travel in a straightline out into space.
174 MHR • Unit 3 Space
Sun’sgravity
gravityturned off
Chapter 6 Close, Far Away, and Really Far Away • MHR 175
The Sun Without the Sun in space, life on Earth would not exist.TheSun is a huge ball of hot gases, similar to billions of otherstarsthat we see in the night sky. In fact, the Sun is a star. TheSunlooks different from other stars because it is part of oursolarsystem and we are much closer to it.
Using observations and measurements from different instru-ments,scientists have learned a great deal about the structureof the Sun.Some of the Sun’s features are shown in Figure 6.3.
• Corona (outer atmosphere): This outer layer can be seen as ahalo around the Sun during a total eclipse when the Moon passesbetween Earth and the Sun.
• Surface gases: At a temperature of about 6000°C, these gasesform the Sun’s visible surface and give the Sun its yellowishcolour.
• Solar flare:When magnetic energy that has built up in thesolar atmosphere is suddenly released, there are sudden brightflares. Flares can be as short as a few seconds or as long as 1h.
• Core: Nuclear reactions in the core produce temperatureshigherthan 15 million °C.
• Sunspots: These areas are cooler and look darker than otherareas on the Sun’s surface.
Figure 6.3 The structure of the Sun
In Spanish the Sunis called el sol. TheFrench term for theSun isle soleil.Notice that bothterms use sol. TheEnglish word“solar”means “connectedwith the Sun.” Useyour dictionary tofindother termsthat have “solar” inthem. List the termsin yournotebook.
The Sun sends huge amounts of energy into space. Forexample, theenergy in a single solar flare is 10 million timesgreater than theenergy released from a volcanic eruption. Onthe other hand, a solarflare produces less than one tenth of thetotal energy produced bythe Sun every second.
Heat from the Sun’s core moves to the surface,producingtemperatures of up to 1 million °C in the corona. Thetemper-ature of the corona is so high that the Sun’s gravity cannotholdit, and the topmost layers of the corona flow away from theSuninto space. This produces a solar wind that moves in alldirectionsat speeds of about 400 km/s.
Light from the Sun is so intense that it can damage youreyes.Never look directly at the Sun.
The PlanetsFor as long as people have known that other planetsexisted, therehas been a desire to know more about them. Is therelife onother planets? Are these other planets like Earth?Astronomersnow know that all the planets differ from one another intheirsize, their atmospheres, their chemical composition, andtheirrotational and orbital periods. No two planets are alike.Scientistssometimes classify the major planets into two groups:rockyplanets and gas giants. Mercury, Venus, Earth, and Marsareclosest to the Sun, and they are mostly made of rock.Jupiter,Saturn, Uranus, and Neptune are furthest from the Sun,andthey are mostly made up of different types of gases. LikeEarth,all of these planets orbit the Sun on their own path.
176 MHR • Unit 3 Space
If the Sun werehollow, you couldfit over one millionEarthsinside!
Why does the Sunlook brighter to usthan other stars?
A Visit to VenusChallengeDesign a model of a vehicle that meetsthedesign specifications below to transport astronauts on thesurface of Venus.
Materialslibrary books Internet accessscissors art suppliespaperfor designing and planningassorted recycled materials for buildingyour model
Safety Precautions
• Take care using scissors.
Design SpecificationsA. Your model must show how twoastronauts
can be carried for 1 km on the surface ofVenus. Be sure toindicate what type offuel your vehicle will use.
B. Your model must consider the followingconditions on thesurface of Venus:• very high temperatures (close to 450°C
day and night, hot enough to melt lead) andextremely highatmospheric pressure (about10MPa, enough to crush a spacecraft)
• the atmosphere is mostly carbon dioxide;thick, white cloudsmade of poisonousacid cover the planet
• gravity is slightly less than on Earth(about 91 percent ofEarth’s gravity)
C. Your model must not be larger than ashoebox.
Plan and ConstructA. In a small group, discuss the different
types of vehicles that could be used.Consider the extremeconditions onVenus. What human needs will you haveto meet? How arethese needs alreadybeing met in space travel? What factorsmake itdifficult to travel on and exploreVenus? Plan several possiblesolutions.
B. Make a list of the materials you could usefor your model.Consider the limitationsof materials now used in space travel—couldyou invent something new? Drawsome possible designs.
C. As a group, select the best design. Draw a labelled sketch ofthe model showingwhat materials you will use.
D. Obtain your teacher’s approval. Then construct the model.
E. Present your model to the class, explainingthe features thatwill help astronautsexplore Venus.
S K I L L C H E C K
Identify the Problem
Decide on Design Criteria
See Also
THE TUNGUSKA INCIDENT, JUNE 30, 1908: A BLAST, A METEORITE, A COMET, OR A THREAT FROM SPACE
Plan and Construct
Evaluate and Communicate
Evaluate1. What improvements did you make to
your original design?
2. How would you change your design ifyou were to build theactual vehicle?
3. Consider your model and your classmates’ models. What ideasdid othergroups use that you would like to use?Give reasons tosupport your answer.
Chapter 6 Close, Far Away, and Really Far Away • MHR 177
Mission to an Alien PlanetYou have learned that new technologiessuchas landers and rovers have been developedduring the history ofspace exploration. Eachnew technology leads to new possibilitiesforknowledge and invention and new insight intothe universe. Inthis investigation you willmodel different stages of a spaceprogram overtime. Use the information you gather at eachstage tocreate a model of an unknown planet.
QuestionHow does new technology lead to new understandings?
Materialsruler binoculars (optional)telescope or spotting scope(optional)digital camera (optional)various materials to make amodel, such as
paper, cardboard, felt pens
ProcedurePrepare a two-column chart with the headings “MissionStage” and“Observations.” Form groups of four orfive, and numberoff. Each student in eachgroup should be a 1, 2, 3, or 4. (Ifyouhave a group of five, two students canwork as one number.)
Your teacher has suspended a mysteryPlanet X from the far end ofa sports fieldor school hallway. All group membersshould observePlanet X from at least 10 m away. Record your observations.Includedetails such as the shape, size, andcolour of the planet.
(Optional) Use binoculars to observe theplanet from the samelocation as in the laststep. Record any new details youobserve.Infer whether the planet has an atmos-phere, water, orlife.
(Optional) Use a telescope to observe theplanet. Record yourobservations. Discussany changes in your ideas or inferencesaboutthe planet.
Student #1 from each group walks halfwayto Planet X and makeobservations. Thestudent returns and shares observations.Record anynew information.
178 MHR • Unit 3 Space
S K I L L C H E C K
Observing
Communicating
Interpreting Observations
Modelling
Mission Stage Observations
10 m away
10 m away with binoculars
Alien Planet Mission
Chapter 6 Close, Far Away, and Really Far Away • MHR 179
Students #2 and #3 walk quickly to 1 mfrom the planet and walkback withoutstopping. Share and record observations.
Student #4 will take take notes whilewalking around the planetfive times.Share and record observations.
(Optional) Have one student walk by theplanet taking severalphotographs with thedigital camera. The class views the picturesona computer and makes observations,notes, and diagrams based on thepictures.As a class, discuss the new information.How did thephotographs change yourideas about Planet X?
Students #1 and #3 now visit the front sideof the planet. Shareand record observations.
Students #2 and #4 now visit the back ofthe planet. Share andrecord observations.
Use the data you have collected to designand construct your ownsmall model ofPlanet X. Compare your model with theoriginalplanet.
Analyze1. (a) What step of the investigation
was similar to viewing a planet from Earth?
(b) What step was similar to flying past the planet?
(c) What step was similar to putting a spacecraft in orbitaround theplanet?
(d) What step was similar to a firstlanding on the planet?
2. (a) How did your observations, notes,diagrams, and inferenceschange asthe tools and technology changed?
(b) What caused these changes?
3. (a) How is your model similar to theoriginal object?
(b) How is it different?
Conclude and Apply4. How are the mission stages you used
similar to exploring Mars or otherplanets and moons?
5. (a) What are three challenges ofexploring other planets?
(b) What technology would help tomeet these challenges?
180 MHR • Unit 3 Space
• closest planet to the Sun
• rocky planet and covered with craters
• daytime temperatures reach 430°C
• nighttime temperatures drop to �180°C
• smallest planet in the solar system
• does not have any moons
Mercury
• second closest planet to the Sun• rocky planet• hottest of allplanets, with temperatures reaching 480°C
Venus
• fourth planet from the Sun
• rocky planet
• reddish in colour because of a material called
iron oxide that is on its surface
• sometimes called the “red planet”
• average temperature is �23°C
• has two small moons
Mars
EarthEarth
• third closest plant to
the Sun
• rocky planet
• is different from other
planets because of
presence of life forms
and large bodies of water
• has one moon
Chapter 6 Close, Far Away, and Really Far Away • MHR 181
It takes Neptune165 years to complete one orbit of the Sun.
• sixth planet from the Sun
• made mostly from gases
• second largest planet in the solar system
• easy to identify because of the rings that surround it
• rings are made of thousands of tiny particles that orbit
the planet
• has many moons
Saturn
• fifth planet from the Sun• made mostly from gases• largestplanet in the solar system• swirling colours you can see areactually clouds high up in its atmosphere• has many, many moons•has giant hurricane with winds of
over 500 km/h
Jupiter
• eighth planet from the Sun• gas planet• almost like a twin
of Uranus but is slightly smaller
• bluish in colour because of methane in its atmosphere
• winds on Neptune can reach 2000 km/h• has 13 confirmedmoons
Neptune
• seventh planet from the Sun
• gas planet
• third largest planet in
the solar system
• bluish in colour because
of a gas called methane
that is in its atmosphere
• has 27 confirmed moons
Uranus
Profile the PlanetsMajor planets in the solar system have beentraditionally divided into two major groups: rocky planets and gasgiants. Planets come in differentshapes, sizes, and colours, aswell as with or without rings. Each planet alsoorbits a differentdistance from the Sun.
QuestionWhich planets are most similar to Earth?
Materials
182 MHR • Unit 3 Space
S K I L L C H E C K
Classifying
Inferring
Interpreting Data
Modelling
Procedure Examine the sizes (diameters) of the dif-ferentplanets in the table. List the planetsin your notebook in order ofsize from thesmallest to the largest.
Your teacher will assign your group oneplanet to study. Observethe sizes of theplanets. Is your group’s planet thelargest,smallest, or in between? Is it similar in sizeto any otherplanet?
Compare your list of planets with the listof balls above. Selectthe ball that bestrepresents your planet.
Determine the distance between the ballrepresenting your planetand the Sun inyour solar system model using one astronomical unit(AU) equal to one metre.An AU is equal to 149 598 000 km(thedistance between Earth and the Sun) andis often used byastronomers to discussdistances in the solar system. Use the tableon the page opposite to determinethe distance.
In the gym, your classroom (if you have areally big classroom),or in a hallway, markthe distance of each planet from the Suninastronomical units (AU).
Write the name of your planet on a sheetof paper. Place thesheet beside your planet.
1 small marble1 Ping-Pong™ ball2 tennis balls2 baseballs 1soccer ball1 basketball
ruler or tape measuresheet of papermasking tape
Chapter 6 Close, Far Away, and Really Far Away • MHR 183
Analyze1. Which planet is the:
(a) largest?(b) coldest?(c) one with the fastest orbitalspeed?(d) closest to the Sun?(e) closest to Earth?(f ) most similarto Earth?
Conclude and Apply2. Why do you think it is important to
know the orbits of the planets when plan-ning a space mission inthe solar system?
3. (a) Which planet is probably the easiestfor people to visit?Explain youranswer.
(b) Which planet is probably the mostdifficult for people tovisit? Explain.
4. Write a short story, poem, or song about the planet you wouldmost like to explore.
Maximum Average Surface DistanceDiameter Distance from SunTemperature Length of Year from Earth Orbital Speed
Planet Name (km) (millions of km) (°C) (in Earth units) (AU)(km/s)
Mercury 4879 70 �170 to 350 88 days 0.39 47.87
Venus 12 104 109 �480 225 days 0.72 35.02
Earth 12 756 152 �22 365 days 1.00 29.79
Mars 6792 249 –23 687 days 1.52 24.13
Jupiter 142 980 816 –150 12 years 5.20 13.07
Saturn 120 000 1507 –180 30 years 9.54 9.67
Uranus 51 800 3004 –210 84 years 19.19 6.84
Neptune 49 500 4537 –220 165 years 30.07 5.48
Suppose you were to make a map of spaceusing 1 cm to representthe distance betweenEarth and the Sun.
• The distance to the next nearest star would be 2.5 km.
• Our Sun is one of over 200 billion stars in agalaxy (group ofstars) called the Milky Way.Using this scale, the Milky Way galaxywouldbe about five times the size of Earth.
• Using this scale, the observable universe wouldbe at least 55times the size of our solar system.
Planet Data
Moons Have you ever wondered why the Moon is not considered tobe a planet? It is spherical, and in space, so what makes itdifferent? The answer depends, in part, on what it orbits. If anobject orbits a planet, and it is not dust, then it is called a
. Compared to the bright colours of the planets, moonssometimesappear to be plain and uninteresting. If you look atEarth’s moon orthe moons of other planets more closely, youwill discover that theyare anything but plain!
Our MoonFor hundreds of years, the composition of the Moonpuzzledscientists. It was not until 1969 that the first astronautslandedon the Moon and brought back samples of the lunar surface.TheMoon is a large, rocky body without water. The rocks onthe surfaceof the Moon are much like the volcanic rocks foundon Earth. As youdiscovered in Activity 6-A, the Moon’s surfaceis also covered withmany craters.
moon
184 MHR • Unit 3 Space
What is the difference betweenmoons and planets?
Figures 6.4 Although the Moon looks smooth from Earth (A), aclose-upphotograph (B) shows that the Moon’s surface is veryrugged.
Why do you think alack of atmosphereallows craters onthe Moon tolast formillions of years?Explain and recordyour answers inanotebook.
B
A
Chapter 6 Close, Far Away, and Really Far Away • MHR 185
The Moon has no atmosphere. An atmosphere covers thesurface of aplanet or moon and is made of numerous gases.Some of theseatmospheres contain a mixture of gases suitablefor life. (Forexample, in Earth’s atmosphere, the gas we need isoxygen.) Withoutan atmosphere, there is no gas to breathe, noozone layer to protectastronauts from dangerous rays from theSun, and nothing to preventasteroids or meteoroids fromreaching the surface.
The Moons of Other PlanetsMercury and Venus are the only planetsin our solar system thatdo not have any moons. The gas giants,however, have many.Some moons are small and very hard to see, evenwith a powerfultelescope. Other moons are quite large and can beseen withbinoculars. Jupiter has the most moons.
www.mcgrawhill.ca/links/ns+science6
Watch videos of thefirst man to walk onthe Moon. Go to theaboveweb site andclick on Web Linksto find out where togo next.
Figure 6.5 Astronomers have foundmany, many moons orbitingJupiter.
Figure 6.6 This photo shows one of Mars’s two moons.
Section 6.1 SummaryIn this section, you learned that:• The solarsystem is very large.• There are eight planets in the solarsystem.• Gravity keeps the solar system together.• Other thanMercury and Venus, all of the other planets have moons.
Check Your Understanding
1. Describe the size of the solar system.
2. Which planets are closest to Earth?
3. Which planets are rocky planets? Which planets are mademostlyof gas?
4. Explain why one object in space is a moon and another is aplanet.
5. Now that you know more about the other planets in oursolarsystem, how is Earth different? Why is it important to takecareof Earth?
6. Describe three challenges for scientists studying theSun.
186 MHR • Unit 3 Space
solar system
moon
Key Terms
Chapter 6 Close, Far Away, and Really Far Away • MHR 187
StarsOn a clear night, away from city lights, you can see morestars inthe sky than you can count. Some are brighter than others,sometwinkle a little more. What are these little dots of light?Just likeour Sun, stars are giant, hot balls of gases that produceheat andlight. Stars come in a range of sizes from one tenth thesize of theSun to about 100 times the size of the Sun. As youlearned before,the Sun looks much larger than a star because it isclose to us.
Looking up at the sky, it appears as if the stars are close tooneanother and are all the same distance away from us.Astronomersnow know that stars are very far away from each otherand areat various distances from Earth. They just look like theyare thesame because we are so far away. Outside of our solarsystem,the closest star is almost 25 000 000 000 000 km away.Thatnumber is 25 million million km. It takes light from thisstarover four years to reach Earth. The distance to the furtheststar that scientists know about is so big that it takes thousandsofyears for its light to reach us on Earth.
Farmers have used the position of stars to tell them when toplant and harvest crops. Sailors andexplorers have used stars toguide them on their journeys before maps and compasses existed.Many cultureshave imagined figures in groups of stars and writtenstories and legends about them. Stars haveplayed an important rolein thehistory of people on Earth.
Section 6.2
C H A P T E R 6C H A P T E R 6
Stars and Constellations
constellation
myth
Ursa Major
Polaris
Key Terms
What are stars?
It is estimated that there are over 70 000 000 000 000 000 000000 starsin the sky, and that is only counting theones we can see!Figure 6.7 All of these stars are actually far away
from each other—and from us.
188 MHR • Unit 3 Space
What are Constellations?are patterns made by stars in thesky.
People have selected these patterns by imagining thatgroups ofstars form shapes of recognizable objects,people (from myths orlegends), or animals. Manycultures have myths or legends that theirpeople associate with the constellation. A is a storythat iscreated to explain an event or to tell about ahero. Theseconstellation myths tell a story about the object, person, oranimal, and explain why theirpicture is in the sky. There are 88constellations inthe sky. Some are only visible in the northernhemi-sphere, while others can only be seen in thesouthernhemisphere. As Earth orbits the Sun, the positions of theconstellations appear to change in the sky. Ofcourse, the stars arenot really moving, it is Earththat is changing position.
One of the most famous constellations in thenorthern sky is , orthe Great Bear. (The body and tail of the bear are also known asthe Big Dipper.) Another well known constellation in the northernsky is Orion. In Greek mythology,Orion was a great hunter. The mythsays that Orion’spride was so great that it annoyed the gods.Theypunished him by sending a scorpion to sting his footand killhim. Artemis, goddess of hunting, thoughtthat Orion should beremembered for his goodhunting skills, so the gods placed him inthe sky.
Constellations and SocietyPeople have spent much time imaginingshapes andfigures out of stars. There are some very good reasonsforthis. By creating constellations, people could easilyfind certainstars as they changed position in the sky.Long ago, these starshelped them figure out importantcalculations like direction andtime of year. Forexample, in climates where there is not muchdiffer-ence between seasons, farmers could look to see thepositionof a certain constellation and know that itwas time to either plantor harvest their crops.
Ursa Major
myth
Constellations
Figure 6.8 These are the starsthat form the constellationUrsaMajor, or Great Bear. Can you locatethe Big Dipper within UrsaMajor?
Figure 6.9 Orion, the Hunter,is another famous constellationinthe northern hemisphere.
What is a constellation?
www.mcgrawhill.ca/links/ns+science6
Find out what constellations are inyour sky for each month. Goto theabove web site and click on WebLinks to find out where to gonext.
Think About ItHow can stars help us to tell time?
MaterialsBig Dipper Time pattern 1 brass fastenersBig DipperTime pattern 2 Scissors
Safety Precautions
• Take care using scissors.
What to DoMaking the Big Dipper Time Clock
Cut out the two circles from Big DipperTime patterns 1 and2.
Place the smaller circle on top of thebigger circle (you shouldbe able to see the months around the edge).
Hold them together by placing a brass fastener through thecentre that is markedwith an “x”.
Turn the circles over and press down thetwo wings of thefastener. You should nowbe able to turn the smaller circle on topofthe bigger circle.
Using the Big Dipper Time Clock
On a cloudless evening, find a safe place inyour backyard, localpark, or schoolyard.
Face north, and find the Big Dipper andPolaris (the North Star)as shown inFigure 6.10.
Hold your Big Dipper Clock so that theNorth Star is at thebottom.
Now turn the top circle until the positionof the Big Dipper andLittle Dipper matchthe position you see in the sky.
Observe your Big Dipper Clock to see ifthe month is correct.
Record your observations in your notebook.
After one hour has passed, repeat steps 6to 8. Record anychanges in the position of the constellations in your notebook.
Chapter 6 Close, Far Away, and Really Far Away • MHR 189
S K I L L C H E C K
Inferring
Predicting
Communicating
Interpreting Data
Analyze1. How reliable do you think the Big
Dipper Clock is for telling time?
2. After one hour, what happened to theposition of theconstellations?
3. Why might this technique be useful tous today, even when wehave watchesand clocks?
Big Dipper Time
November
July
June
May
Decem
ber
October
September
August
April
Mar
ch
Febr
uary
Janu
ary
North Star
Little Dipper
Big Dipper
Star Clock
190 MHR • Unit 3 Space
Find Out ACTIVITY
Stars and Ancient CivilizationsHow did ancient civilizations usethe starsin their society?
What to Do
1. Working with a group, choose an ancientcivilization such asthe Egyptians, Celts,or Aztecs.
2. Using your library, find out information onhow people in yourancient civilizationused stars to help them. (Use searchwords likeancient � Egyptian �astronomy.) Assign each group memberthe task offinding one way your ancientcivilization used stars to helpthem.
3. Record your information in a notebookas you will bepresenting your informa-tion to the class.
4. As a group, decide how you will presentyour findings to yourclass. You maywant to present it as a news show, orthrough aposter.
What Did You Find Out?
1. In what ways did some ancient civiliza-tions use stars? Arethere any commoncharacteristics among the civilizations?
2. What is one method of using the starsyou would like to beable to do on yourown? In your notebook, list three stepsthat wouldhelp you learn this method.
6–G
Before maps and compasses existed, sailors andexplorers dependedon the stars. , theNorth Star, is important because it can be usedfornavigation. Polaris shows mariners which directionis north,which is an important piece of informationfor navigating the oceansand lands of the world.
PolarisPolaris
Ursa Minor
Ursa Major
Figure 6.10 Knowing where to find Polaris, the North Star,helpedmany explorers and sailors navigate through unknownoceans andlands. To find Polaris, follow the two stars in the“scoop” of theBig Dipper (located within Ursa Major) andfollow them up to thenext brightest star. This star is Polaris,which forms the end ofthe handle of the Little Dipper (whichis also the end of the tailfor Ursa Minor).
Chapter 6 Close, Far Away, and Really Far Away • MHR 191
Find Out ACTIVITY
Star Light, Star Bright
6–H
The brightest star in the sky is called Sirius. Itis located inthe constellation Canis Major, or Big Dog. Sirius is twice as bigas our Sun andis 23 times as bright!
In this activity, you will be learning how to identify some ofthe constellations in the sky.
Materials
cylindrical box or cancompasssheet of black construction paperanelastic bandscissorschalkflashlightbooks and Internet sourcesabout
constellations and mythology
Safety Precautions
• Take care using scissors.
What to Do
1. Using books or the Internet, select oneconstellation andresearch what it lookslike and the myth or legend that explainswhythat figure is in the sky. Recordyour information in yournotebook.
2. Remove both ends of the box or can.
3. Use a compass to draw a circle on theblack construction paperabout 5 cmwider than the end of the box or can.
4. Using a pencil or white pencil crayon,draw the constellationinside the circle.Make sure to leave a margin betweenyourconstellation and the edge of the circle.
5. Cut out the circle, and place it over oneend of the can orbox. Secure it in placewith an elastic band.
6. With the end of the compass, poke holeswhere each star in theconstellation islocated.
7. Next, put a flashlight through the open end of the can orbox, anddarken the room.
8. Point the papered end toward theceiling until a clear imageof the constellation appears.
9. Share your constellation with the classand tell the myth orlegend that goesalong with the constellation.
What Did You Find Out?
1. How can you identify your constellationin the night sky?
2. What are some common characteristicsin the myths?
3. What is your favourite constellation?Explain your answer.
192 MHR • Unit 3 Space
Section 6.2 SummaryIn this section, you learned that:•Constellations are patterns of stars in the sky.• Constellationsare useful in helping people locate stars in the sky.• People oftencreated a myth to explain why the constellation is in
the sky.• Stars help people know the time of year and helpedexplorers and
sailors navigate and explore land and sea.
Check Your Understanding
1. What is a constellation?
2. Provide one reason people created constellations out of thestars.
3. How did people use the stars to help them withactivities?
4. List four constellations and describe the myth that explainswhythey are in the sky.
5. Choose one ancient method of using the stars. How mightthatmethod be useful to you today?
Imagine you have the opportunity to visit anyplanet in our solarsystem. Which planet wouldyou pick? Using the information that youknowabout this planet, draw a picture of what it lookslike fromyour view while standing on the surface.
constellation
myth
Ursa Major
Polaris
Key Terms
Chapter 6 Close, Far Away, and Really Far Away • MHR 193
Prepare Your Own Chapter Summary
Summarize this chapter by doing one ofthe following: • Create agraphic organizer such as a
concept map.• Produce a poster.• Write a summary to include thekey
chapter ideas.
Here are a few ideas to use as a guide:• Create a model of yourfavourite planet.• Make a poster of all the planets in
their correct position from the Sun.• Design a pamphlet thatillustrates and
describes five constellations in your sky.
194 MHR • Unit 3 Space
Q. What inspires you about this field? A. The more I think aboutMars, the more
amazed I am that there is another worldout there, so like ours,which perhapsstarted out exactly like ours did. As ourimages andinformation about Mars getbetter, we find some conditions thatareeerily like Earth—winds blow, cloudsform, and we see ancientriver beds.There are lots of similarities with thelandscapes ofEarth’s Polar Regions. Asa physicist, I love the idea of aworldjust a little bit more extreme than oursthat has evolved to beso different.
Q. What is your team doing and how are yougoing to accomplishit?
A. The Canadian science team for thePhoenix Mission will use theMET(Meteorological Station), a Canadianweather station, to studythe weather inthe Martian Arctic. On Mars, we wantto understand whyrivers don’t flow onthe surface any more. It has taken fiveyears todevelop and build the MET
station, which uses temperature andpressure sensors similar tothose onweather stations in Earth’s Arctic. It also uses LIDAR(light detection andranging instrument), a laser-basedtechnologyfor which Canada isrecognized, to determine the height of cloud anddust layers on Mars.
Q. What is the role of each member? A. There are a lot of peopleinvolved in
the Canadian MET team: scientists,engineers, students, publicrelationsexperts, educators, and managers! Ourjob is to interpretthe science data wereceive, using our experience of Earthandsimulations of what we expect tofind on Mars. The first stageisdeveloping and testing the instrument.The focus then shifts totraining foroperating the instrument once themission reaches Mars.We will do thisas a team through a special terminalthat lets ussend commands to theinstrument once per day and receiveour data inreturn. Mars is so far away
Dr. Victoria Hipkin is a program scientist at theCanadian SpaceAgency (CSA). As part of herresearch on planetary exploration, shestudiesatmospheric science, trying to find clues aboutthe past andpresent climate on Mars. She iscontributing to the Phoenix MarsMission, part of NASA’s Scout Program, which will study thehistoryof water on Mars and the potential for life there. Dr. Hipkin workson science instrumentdevelopment for planetary missions andworkswith teams on initial plans for missions thatmight happen 20years from now. Dr. Victoria Hipkin
a
Program ScientistU N I TU N I T
3 Ask3
that the data can take up to 40 minutesto travel through space.The engineerson the team have come from industryand the CSA andhave been responsiblefor building the instrument. They willalso beresponsible for checking thecommands and the health oftheinstrument. Public relations expertshelp with web page designand publicevents. Educators help school studentslearn andparticipate in the mission.Managers try to make sure thateverythingis well planned and thatthere are enough resources to let theteamwork properly.
Q. What skills or training do various membershave that areimportant in the work?
A. Imagination, passion, and criticalthinking are important inresearch andscience in general and are definitelyimportant forplanetary missions, whereso much is unknown. Space engineersandtechnologists need to be systematic,organized people in order toplan forspace operations. A broad range oftraining can prepare youfor planetarymissions. To be a science team member,you need ascience degree. Planetaryscientists have training inphysics,geology, biology, chemistry, or geography.
Q. Who benefits from the work that you do? A. This will be thefirst laser on the
surface of another planet. An immediatebenefit is to otherscientists around theworld. Our mission will generate newdata thatwill change how we think ofMars. This mission is alsofabuloustraining for the Canadian students andyoung researchers andengineersinvolved and will be a launch pad tointernational careersin an exciting,cutting-edge field.
Q. What advice would you give to a student whois interested inthis field?
A. Believe that you can be part of thespace program if you wantto be! Findthe aspect of it that interests you most.Don’t be afraidto contact people andask questions. If you would likehands-onexperience as an undergraduate student,look for a co-opprogram or for summerplacements. Most Mars data is posteddirectlyto the Internet, so you can lookat images from Mars and do yourownresearch from home! Look for publicand student programs andsocieties.There are lots of ways to get involved!
Unit 3 Ask a Program Scientist • MHR 195
The Phoenix Mission will help scientistsfind out whether waterand other mole-cules have ever existed on Mars. Thisinformationwill allow comparisonsbetween the climates on Earth and Mars.Inaddition, it may explain whether life everexisted on Mars, andwhether it is possiblefor humans to explore the planetfurther.International teams have worked together tocarry outmissions to Mars. As technology
brings us closer to understanding the mys-teries of the redplanet, how will we answerthe questions that arise: Who ownsMars?How should we decide what direction Marsexploration takes?Visit some of the websites related to the exploration of Marsandprepare a statement for a potential debateon the subject. Visitwww.mcgrawhill.ca/links/ns+science6 and follow the linksindicatedto begin your research.
196 MHR • Unit 3 Space
Q. What inspires you about this field?A. I am inspired andmotivated by the
exploration and discovery aspects ofworking in the spaceindustry. It is trulyexciting to be part of a team that isputtingCanada’s next-generationrobotic system into orbit.
Q. What is your team doing and how are yougoing to accomplishit?
A. We are working toward the successfullaunch and commissioningof Dextre,Canada’s final contribution to the MobileServicing Systemof the InternationalSpace Station. The Mobile Base SystemandCanadarm2 components are alreadyon orbit and have been a crucialtool forassembly of the space station. Dextre willbe used toperform robotic maintenanceof the external components of thestation.This will be the world’s first on-orbitservicing robot withan operationalmission. Dextre will lead the way fordevelopments inrobotic support tolunar and Martian exploration missions.
Q. What is the role of each member?A. The team of systemsengineers I lead at
the Canadian Space Agency (CSA) isfocused on the technicalaspects ofensuring Dextre’s readiness. The teamincludes membersfrom NASA’sJohnson Space Center; MDA SpaceSystems in Brampton,Ontario; andNASA’s Kennedy Space Center. Thebroader team at CSAincludes softwarespecialists, safety and qualityassurancespecialists, mission planners, trainingproduct developers,robotics instructors,managers, and directors.
The team at MDA Space Systemsincludes mechanical, electrical,thermal,parts, quality, safety, software, andsystems engineers, allspecialized inspace applications. The technicians who manufacturethe components and the technicians who assemble thesystem are vitalmembers of the team.
Daniel Rey is the project engineer responsiblefor the Dextreproject at the Canadian SpaceAgency. Dextre, a “Special PurposeDexterousManipulator,” is a two-armed robot that willattach toeither the Mobile Base System or theCanadarm2 at the InternationalSpace Station.Dextre will do tasks that normally would be doneby anastronaut. This technology is importantbecause the harshenvironment of space makesit difficult and dangerous for astronautsto workoutside the station.
a
Project EngineerU N I TU N I T
3 Ask3
Daniel Rey
Q. What skills/training do various membershave that areimportant in the work?
A. It is common for the senior engineersto have significantexperience workingin the aerospace field or a Master’sdegree inengineering specializing inthe aerospace field. Bachelor’sdegreesin engineering don’t need to bespecialized in aerospace.
Q. Who benefits from the work that you do?A. The Canadian SpaceAgency’s goal is
“to promote the peaceful use anddevelopment of space, to advancetheknowledge of space through science, and to ensure that spacescience andtechnology provide social and economicbenefits forCanadians.”
The Dextre project, in particular,contributes to the strategicoutcome ofadvancing knowledge, innovation, andthe Canadian economy.The success ofCanadarm was an internationallyrecognizedachievement. It demonstratedCanadian technical savvy andexcellence.The success will be renewed andsustained by Dextre.
Q. What advice would you give to a student whois interested inthis field?
A. Try to identify your natural skills andinterests and letthese guide you. Seekadvice from a dedicated, professionallytrainedcareer counsellor if you arehaving trouble identifying adirectionfor your interests. If you know that you are interested inthe space industry,seek opportunities for enjoyableextra-curricular activities and challengesrelated to space scienceor aerospaceengineering. Science fairs, contests,astronomy clubs,university or industrialopen houses can help you discover anewpassion.
Finally, consider a co-operativeacademic program for yourBachelor’sdegree. This will give you theopportunity for regular,structuredexposure to a variety of positions ofyour choosing. Notethat you do haveto compete for these positions, so goodgrades canbe very helpful. Good luckon whatever path you choose!
Dextre is able to move objects and smalltools. Sensors allow itto “feel” its sur-roundings and objects that it is holding andreactto changes in position or pressure. Italso has lights and videocameras thatallow astronauts inside the InternationalSpace Stationto observe its work.
Find out more about Canadian tech-nology designed for theInternationalSpace Station. How does Dextre differ fromtheCanadarm2? How could the technologybe used on Earth? Prepare yourideas on
how Dextre would be useful, and write a short proposal outliningthe details ofwhere and how it would be used.
Unit 3 Ask a Project Engineer • MHR 197
198 MHR • Unit 3 Space
Project
Wanted: A Junior Astronaut
U N I T 3U N I T 3
S K I L L C H E C K
Communicating
Inferring
Evaluating
Imagine that you saw the following advertisement for an openingon the team at the International Space Station:
ChallengeRespond to this advertisement with details of theknowledge, skills, and experience youwill bring to the mission.Your response maybe in the form of a video, a mock interview, awritten résumé or application, or anotherformat of your choice.
Design Criteria Include the following in your application.A.Explain why you are interested in visiting
the International Space Station.B. Outline the experiences youhave had that
show you could meet the qualifications. C. Describe yourknowledge of the
International Space Station.D. Note some of the challenges youexpect
to face in traveling to the InternationalSpace Station.
E. Explain how you will meet your basicneeds in space and howyou will respondto the special requirements of working intheInternational Space Station.
F. Describe two technologies used in theInternational SpaceStation that youwould be interested in working with and how youwould use them.
THE CANADIAN SPACE AGENCY IS NOW
ACCEPTING APPLICATIONS FOR THE POSITION OF
Junior Astronaut to Visit International Space Station
We are looking for an individual between the ages of 10 and 15to visit the ISS as a junior astronaut. The successful applicantwill be assisting astronauts in performing scientific tests, aswell as contributing to a study of the effects of weightlessness onyoung people.
The ideal person for the job will have the followingqualifications:• has a love of adventure• responds well to newchallenges and
unfamiliar surroundings• has knowledge of the needs involvedin
living and traveling in space• is physically fit• does not mindworking in small spaces
Plan and ConstructCreate an outline of your applicationbased onthe design criteria and qualifications requested.
Use what you have learned about spacein this unit, plus extraresearch if neces-sary to fill in details in your application.
Choose the format for your applicationto the International SpaceStation.
Organize this information into a persua-sive presentation ofyour qualificationsfor the mission.
Present your application to your class.
Evaluate1. How did your application compare to
the applications of other students? Whatdo you think makes astrong application?Do you think you would be accepted fortheexperience?
2. What additional knowledge or experiencemight increase yourchances of beingchosen?
3. Would you want to be chosen for thisexperience? Explain whatyou werethinking as you made this decision.
Unit 3 Unit Project • MHR 199
/ColorImageDict > /JPEG2000ColorACSImageDict >/JPEG2000ColorImageDict > /AntiAliasGrayImages false/CropGrayImages false /GrayImageMinResolution 150/GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true/GrayImageDownsampleType /Bicubic /GrayImageResolution 1200/GrayImageDepth -1 /GrayImageMinDownsampleDepth 2/GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true/GrayImageFilter /DCTEncode /AutoFilterGrayImages false/GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict >/GrayImageDict > /JPEG2000GrayACSImageDict >/JPEG2000GrayImageDict > /AntiAliasMonoImages false/CropMonoImages false /MonoImageMinResolution 300/MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true/MonoImageDownsampleType /Bicubic /MonoImageResolution 1200/MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000/EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode/MonoImageDict > /AllowPSXObjects false /CheckCompliance [ /None] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false/PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.000000.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true/PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ]/PDFXOutputIntentProfile (None) /PDFXOutputConditionIdentifier(Custom) /PDFXOutputCondition () /PDFXRegistryName () /PDFXTrapped/False
/Description > /Namespace [ (Adobe) (Common) (1.0) ]/OtherNamespaces [ > > /FormElements true /GenerateStructurefalse /IncludeBookmarks false /IncludeHyperlinks false/IncludeInteractive false /IncludeLayers false /IncludeProfilesfalse /MarksOffset 18 /MarksWeight 0.250000 /MultimediaHandling/UseObjectSettings /Namespace [ (Adobe) (CreativeSuite) (2.0) ]/PDFXOutputIntentProfileSelector /UseName /PageMarksFile/RomanDefault /PreserveEditing true /UntaggedCMYKHandling/LeaveUntagged /UntaggedRGBHandling /UseDocumentProfile/UseDocumentBleed false >> ]>> setdistillerparams>setpagedevice

(PDF) Close, Far Away, - Nelsonlearningcentre.nelson.com/student/9780070988507/...have less inﬂuence. If the Sun were to suddenly disappear, its mass would vanish, and its gravitational - DOKUMEN.TIPS (2023)