MHE_Rdg_Wonders_LvRdr_G3_On-Level_U3W3_13.pdf

Expository TextPAIREDREADWhy the Stars TwinkleDestinationDestinationSaturnSaturnby Karen Alexanderby Karen AlexanderProgram:CR 14Component:LRG3 Ux Wx X2RVendor:Learning MediaLevel:30Program:CR 14Component:LRG3 U3 W3 OPDFCV_CR14_LR_G3_U3W3L30_O_119006.indd 2CV_CR14_LR_G3_U3W3L30_O_119006.indd 213/02/12 11:51 AM13/02/12 11:51 AMSTRATEGIES&SKILLSAPhotography Credit:Cover NASA/JPL/Space Science Institute.*The total word count is based on words in the running text and headings only.Numerals and words in captions,labels,diagrams,charts,and sidebars are not included.Word count:1,113*ComprehensionStrategy:SummarizeSkill:Main Idea and Key DetailsVocabulary StrategySuffixesVocabularyamount,astronomy,globe,solar system,support,surface,temperature,warmth Content StandardsScienceEarth and Space ScienceProgram:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30Copyright The McGraw-Hill Companies,Inc.All rights reserved.No part of this publication may be reproduced or distributed in any form or by any means,or stored in a database or retrieval system,without the prior written consent of The McGraw-Hill Companies,Inc.,including,but not limited to,network storage or transmission,or broadcast for distance learning.Send all inquiries to:McGraw-Hill EducationTwo Penn PlazaNew York,New York 10121ISBN:978-0-02-119006-5MHID:0-02-119006-2Printed in the United States.1 2 3 4 5 6 7 8 9 DOC 15 14 13 12 11 10IFCIBC_CR14_LR_G3_U3W3L30_O_119006.indd 2IFCIBC_CR14_LR_G3_U3W3L30_O_119006.indd 213/02/12 11:52 AM13/02/12 11:52 AMPAIREDREADChapter 1Exploring Saturn .2Chapter 2Mission to Saturn .8Chapter 3Storm on Saturn .13Respond to Reading.15Why the Stars Twinkle .16Glossary/Index.19Focus on Science.20by Karen Alexanderby Karen AlexanderDestination SaturnEssential QuestionWhat do we know about Earth and its neighbors in space?Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30001_009_CR14_LR_G3_U3W3L30_O_119006.indd 1001_009_CR14_LR_G3_U3W3L30_O_119006.indd 113/02/12 11:58 AM13/02/12 11:58 AMChapter 1Exploring SaturnPeople have been studying the stars and planets for thousands of years.This study is called astronomy.Even before telescopes were invented,people had found the planet Saturn.With the help of spacecraft,we are learning new things about Saturn.Saturn is the second biggest planet in our solar system.It is also the sixth planet from the sun.The Solar SystemMercuryVenusEarthMarsJupiterSaturnUranusNeptuneSun2Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30 Stocktrek/Alamy001_009_CR14_LR_G3_U3W3L30_O_119006.indd 2001_009_CR14_LR_G3_U3W3L30_O_119006.indd 213/02/12 11:58 AM13/02/12 11:58 AMSaturn doesnt look like a globe.It looks as if someone has pushed the top and bottom of a ball together.It looks like this because it rotates fast.Saturn has a rocky center,but its surface is gas.It could not support human life.Saturn is many times bigger than Earth.SaturnEarthGas PlanetSaturn is a gas planet.The rock at its center is probably so hot that it is liquid.Jupiter,Uranus,and Neptune are gas planets,too.Gas planets are much bigger than planets that are made up of metal and rock,such as Earth.Those are called terrestrial planets.3Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30(tl)NASA/JPL/Space Science Institute,(tr)NOAA/NASA GOES Project 001_009_CR14_LR_G3_U3W3L30_O_119006.indd 3001_009_CR14_LR_G3_U3W3L30_O_119006.indd 313/02/12 11:58 AM13/02/12 11:58 AMThe Rings of SaturnSaturn is the easiest planet to recognize because of its rings.All the gas planets have rings,but Saturns are the biggest and most noticeable.The rings are mainly ice,with bits of rock and dust.The pieces vary in size.Some are the size of a grain of sand.Some are the size of a mountain.The rings extend thousands of miles from Saturn.However,they are only about half a mile thick.Scientists think that Saturns rings might have formed from pieces of moons that had broken up.Saturns ringsProgram:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30 4NASA/JPL/Space Science Institute001_009_CR14_LR_G3_U3W3L30_O_119006.indd 4001_009_CR14_LR_G3_U3W3L30_O_119006.indd 413/02/12 11:58 AM13/02/12 11:58 AM Eight groups of rings have been discovered so far.They were named in alphabetical order as they were discovered.There are many rings in each group,and gaps between the rings.Discovering the RingsThe astronomer Galileo was the first person to look at Saturn through a telescope and see Saturns rings.Galileo could not see exactly what the rings were.He drew them as if they were handles.Huygens,a Dutch astronomer,worked out that the shape was a ring.The astronomer Cassini realized that there were at least two rings.The space between Rings A and B is now called the Cassini Division.GalileoDid You Know?Did You Know?If Saturn were put in a huge pond,it would float.5Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30Library of Congress Prints and Photographs Division LC-USZ62-7923001_009_CR14_LR_G3_U3W3L30_O_119006.indd 5001_009_CR14_LR_G3_U3W3L30_O_119006.indd 513/02/12 11:58 AM13/02/12 11:58 AMMany MoonsEarth has just one moon.Saturn,however,has many moons.Fifty-three of them have names,but more are being discovered all the time.Titan was the first moon to be discovered.It is also the biggest.In fact,it is bigger than the planet Mercury.The moons are all different.Many moons are icy.Some are huge.Some are tiny.Some even have their own rings.The moon Phoebe travels around Saturn in the opposite direction from the way Saturn travels.SaturnPhoebeProgram:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30 6NASA/JPL-Caltech001_009_CR14_LR_G3_U3W3L30_O_119006.indd 6001_009_CR14_LR_G3_U3W3L30_O_119006.indd 613/02/12 11:58 AM13/02/12 11:58 AMSome of the moons orbit inside the rings.They are called“shepherd”moons.That is because the force of gravity between them and the rings can move the rings around.Two of the moons share the same orbit.They travel within 30 miles of each other.Every four years,the outside one catches up with the inside one and they swap places.Did You Know?Did You Know?A day on Saturn is 10 hours and 39 minutes,in Earth time.A year is 29.5 Earth years.Dione is one of Saturns icy moons.Some of Saturns rings can be seen behind Dione.Dione7Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30NASA/JPL/Space Science Institute001_009_CR14_LR_G3_U3W3L30_O_119006.indd 7001_009_CR14_LR_G3_U3W3L30_O_119006.indd 713/02/12 11:58 AM13/02/12 11:58 AMChapter 2 Mission to Saturn Scientists have been learning more about Saturn with the help of spacecraft.In 1997,a space mission left Earth to study the planet and its moons and rings.The Cassini-Huygens spacecraft took seven years to travel from Earth to Saturn.The spacecraft orbited Saturn,and sent information about the planet back to Earth.It then divided into two.One part,Huygens,landed by parachute on Titan.Its instruments sent information and images of Titan back to Earth.Did You Know?Did You Know?When the mission began in 1997,only 18 of Saturns moons had been discovered.The Cassini mission found some more.Others were discovered with the use of improved telescopes.8Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30 NASA001_009_CR14_LR_G3_U3W3L30_O_119006.indd 8001_009_CR14_LR_G3_U3W3L30_O_119006.indd 813/02/12 11:58 AM13/02/12 11:58 AMThe Long Way RoundSaturn is 800 million miles from Earth,but the Cassini-Huygens spacecraft went a lot farther than that to get there.It traveled about two billion miles.Why?A spacecraft cannot carry enough fuel for such a long journey.However,gravity is helpful in space travel.The spacecraft flew past Earth,Venus,and Jupiter.These fly-bys helped it to build up speed.For most of the voyage,the spacecraft floated through space without using its engines.When the spacecraft got to Saturn,it used its engines to slow down enough to enter Saturns orbit.This is an artists impression of the Huygens spacecraftlanding on Titan.9Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30Craig Attebery/NASA001_009_CR14_LR_G3_U3W3L30_O_119006.indd 9001_009_CR14_LR_G3_U3W3L30_O_119006.indd 913/02/12 11:58 AM13/02/12 11:58 AMThe Cassini-Huygens spacecraft discovered a huge amount of exciting information about Titan.Astronomers think that Titan might be like Earth was when it was young.It is the only moon in our solar system that has clouds and an atmosphere.Photos taken by the spacecraft show that the landscape of Titan is similar to that of Earth.Titan has river valleys and mountains.Titan might also have weather patterns that are like those on Earth,with rain and wind.The surface of Titan is much too cold for any water to be liquid.However,scientists think there may be an ocean under the surface.This painting of Titans surface is based on information sent by the Cassini-Huygens spacecraft.10Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30 (t)CassiniImagingTeam NASA/JPL/SSI(b)StevenHobbs/NASA/JPLNASA/JPL010_015_CR14_LR_G3_U3W3L30_O_119006.indd 10010_015_CR14_LR_G3_U3W3L30_O_119006.indd 1015/02/12 10:26 AM15/02/12 10:26 AMThe mission found out about other moons,too.Hyperion looks like a jagged piece of rock.Its shape is very unusual.Most objects that rotate in space are basically round.Huygens was the first spacecraft to land anywhere in the outer solar system.CassiniHuygensHyperionProgram:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:3011(t)Cassini Imaging Team,NASA/JPL/SSI,(b)Steven Hobbs/NASA/JPL010_015_CR14_LR_G3_U3W3L30_O_119006.indd 11010_015_CR14_LR_G3_U3W3L30_O_119006.indd 1115/02/12 10:26 AM15/02/12 10:26 AMThe moon Enceladus looks bright because it is covered with ice.The ice reflects the sunlight back into space.Jets of icy water spray from Enceladus.Instruments in the Cassini spacecraft tested the water and found that it is like Earths oceans.Scientists believe this may mean there is liquid salt water beneath the moons crust.There is also warmth on Enceladus.Scientists think the warm temperature means there is heat deep inside Enceladus.Icy vapor rises from Enceladus.Saturn is a long way from the sun.The planet and its moons get much less sun than Earth gets.12Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30 NASA/JPL010_015_CR14_LR_G3_U3W3L30_O_119006.indd 12010_015_CR14_LR_G3_U3W3L30_O_119006.indd 1215/02/12 10:26 AM15/02/12 10:26 AMWhen the Cassini mission ends in September 2017,the spacecraft will have been at Saturn for nearly half a Saturn year.One of the more amazing events of the mission has been to track a huge thunderstorm on Saturn.The storm stretches around the whole planet,sending streams of gas into Saturns atmosphere.The storm covers an area eight times greater than the area of Earth.Scientists say it is much more powerful than any storm on Earth.Scientists find it exciting to see the storm on Saturn because storms on Saturn are rare.Chapter 3 Storm on Saturn13Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30NASA/JPL 010_015_CR14_LR_G3_U3W3L30_O_119006.indd 13010_015_CR14_LR_G3_U3W3L30_O_119006.indd 1315/02/12 10:26 AM15/02/12 10:26 AM People study astronomy for many reasons.They want to find out more about the universe.They also want to see if there is life on any other planet or moon.The Cassini mission has already revealed a great deal about Saturn.Some of the most exciting information relates to the moons Titan and Enceladus.Titan may teach us more about Earth when it was a young planet.Enceladus has warmth and water,two cornerstones of life.Who knows what other amazing discoveries will be made in the future!Saturn14Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30 NASA/JPL/Space Science Institute 010_015_CR14_LR_G3_U3W3L30_O_119006.indd 14010_015_CR14_LR_G3_U3W3L30_O_119006.indd 1415/02/12 10:26 AM15/02/12 10:26 AMMain IdeaDetailDetailDetailSummarizeSummarize what you have learned about Saturn.Use the Main Idea and Key Details Chart to help you.Text Evidence 1.How do you know that Destination Saturn is an expository text?GENRE 2.Reread page 10.Why are scientists interested in Titan?MAIN IDEA AND KEY DETAILS 3.What does icy on page 12 mean?Rewrite the sentence using ice instead of icy.SUFFIXES4.Write about why the mission to Saturn is important.Use details from the text to support your answer.WRITE ABOUT READING15Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30010_015_CR14_LR_G3_U3W3L30_O_119006.indd 15010_015_CR14_LR_G3_U3W3L30_O_119006.indd 1515/02/12 10:26 AM15/02/12 10:26 AMLong,long ago,Earth and the sky were not far apart,as they are now.They were close together.People on Earth could touch the sky.One day,a woman went outdoors to grind rice for her family s meal.The woman had lovely,long,silky hair.She spent a great deal of time brushing it.She was also very proud of her jewelry,and wore it even when she was working.It was a hot day,and the woman didn t want to be working.She put a large amount of grain into a wooden bowl so she could grind it all at once.She started to smash it with a heavy tool called a pestle.It was hard work.The woman got angry.Compare TextsYou have read about a space mission to Saturn.Now learn how people used to explain the universe.WHY THE STARS TWINKLE16Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30 Illustration:Pamela Becker016_020_CR14_LR_G3_U3W3L30_O_119006.indd 16016_020_CR14_LR_G3_U3W3L30_O_119006.indd 1615/02/12 10:10 AM15/02/12 10:10 AMEach time the woman pounded the rice,she raised the pestle higher.As she worked,she got a blister where her gold ring rubbed the skin on her finger.She took off the ring and hung it on the sky.The silver comb in her hair fell out.That made her angrier.She hung her comb on the sky.Then her necklace got in the way of the pestle,so she hung that on the sky,too.Each time the woman raised the pestle,she pushed the sky farther away.She was so busy that she didn t realize what was happening.17Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30016_020_CR14_LR_G3_U3W3L30_O_119006.indd 17016_020_CR14_LR_G3_U3W3L30_O_119006.indd 1715/02/12 10:11 AM15/02/12 10:11 AMMake ConnectionsWhy do you think Why the Stars Twinkle was written?ESSENTIAL QUESTION In what way does the explanation for the stars,moon,and sun in Why the Stars Twinkle differ from the descriptions of space in Destination Saturn?TEXT TO TEXTAt last,the woman finished her work.She wiped her brow and stood back.As she did,she felt air brush her face.She looked up to find that the sky was now far,far above her.Away in the distance,she could see her ring,comb,and necklace,but she couldn t reach them.You can still see her jewelry.Her silver comb became the moon,and her gold ring became the sun.Her sparkly necklace became the stars that twinkle across the surface of the sky.18Program:CR 14Component:LRG3 U3 W3 OPDFVendor:Learning MediaLevel:30 Illustration:Pamela Becker016_020_CR14_LR_G3_U3W3L30_O_119006.indd 18016_020_CR