The Solar System and The Solar System and Some Early AstronomersSome Early AstronomersThe Solar System and The Solar System and

Some Early AstronomersSome Early Astronomers

Category 1 of 1

Question:

Galileo thought that _________ __________ created the tides. This shows that even someone known as “the father of modern science” can make a mistake. (p. 300)

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Category 1 of 1

Answer:

Earth’s rotation

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Category 2 of 1

Question:

Ulug Bek’s ________ was the best in the world during his time. (p. 296)

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Category 2 of 1

Answer:observatory

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Category 3 of 1

Question:The _______ ________ is an immense spherical cloud. It surrounds the solar system and reaches about three light-years from the sun. (p. 294)

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Category 3 of 1

Answer:Oort Cloud

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Category 4 of 1

Question:The _____________ Belt is a vast region extending beyond Neptune. (p. 294)

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Category 4 of 1

Answer:Edgeworth-Kuiper

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Category 5 of 1

Question:___________ draw close to the sun and then fly far out into space. (p. 294)

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Category 5 of 1

Answer:Comets

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Category 1 of 2

Question:

Most ___________ are in a belt that lies between Mars and Jupiter. (p. 294)

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Category 1 of 2

Answer:asteroids

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Category 2 of 2

Question:On 24 August 2006 the International Astronomical Union voted to reclassify Pluto as a “___________.” (p. 293)  

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Category 2 of 2

Answer:dwarf planet

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Category 3 of 2

Question:Clyde W. Tombaugh discovered _______ on 18 February 1930. For seven months he had searched for something he knew had to be there: a heavenly body that tugged on Neptune, just as Neptune tugged on Uranus. (p. 293)

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Category 3 of 2

Answer:Pluto

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Category 4 of 2

Question:Although he didn’t have a ___________, Copernicus did have other instruments to study the sky. (p. 288)

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Category 4 of 2

Answer:telescope

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Category 5 of 2

Question:•Astronomers believed for centuries that the ________ was the center of the solar system. This belief was even part of church doctrine. (p. 286 )

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Category 5 of 2

Answer:Earth

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Category 1 of 3

Question:•This “Red Planet” is visible to the naked eye as a reddish dot in the sky. (p. 291)

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Category 1 of 3

Answer:Mars

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Category 2 of 3

Question:By far the largest planet, this gas giant has 16 known moons. (p. 291)

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Category 2 of 3

Answer:Jupiter

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Category 3 of 3

Question:This planet, the second largest in the solar system, is known as the “ringed planet.” (p. 292)

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Category 3 of 3

Answer:Saturn

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Category 4 of 3

Question:This planet, the third largest, is a ringed planet, and it spins on its side. (p. 292)

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Category 4 of 3

Answer:Uranus

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Category 5 of 3

Question:Astronomers discovered this planet after noticing that some body was exerting a gravitational tug on Uranus. (p. 293)

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Category 5 of 3

Answer:Neptune

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Category 1 of 4

Question:The largest object in the solar system. (p. 289)

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Category 1 of 4

Answer:The sun

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Category 2 of 4

Question:The smallest planet, and the one closest to the sun. (p. 289).

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Category 2 of 4

Answer:Mercury

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Category 3 of 4

Question:

This planet is cloaked in a thick layer of clouds made up of water and sulfuric acid. (p. 290

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Category 3 of 4

Answer:Venus

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Category 4 of 4

Question:•The only planet to sustain life as far as we know. (p. 290)

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Category 4 of 4

Answer:Earth

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Category 5 of 4

Question:The gravity of this body creates the tides on Earth. (p. 290)

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Category 5 of 4

Answer:

The moon

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Category 1 of 5

Question:

•Who discovered four “stars” near Jupiter and decided they were moons? (p. 299)

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Category 1 of 5

Answer:Galileo

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Category 2 of 5

Question:Which early astronomer showed that orbits of the planets weren’t perfect circles, but ellipses, or ovals? (p. 299)

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Category 2 of 5

Answer:

Kepler

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Category 3 of 5

Question:•Who was one of the first to use the modern scientific method? (p. 298)

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Category 3 of 5

Answer:Kepler

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Category 4 of 5

Question:•Which early astronomer published the first major catalog of stars since Ptolemy’s? (p. 297)

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Category 4 of 5

Answer:Ulug Bek

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Category 5 of 5

Question:Which early astronomer is known not for his own work but for the way he combined other astronomers’ ideas? (p. 295)

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Category 5 of 5

Answer:Ptolemy

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Chapter 7, Lesson 1

Chapter OverviewChapter OverviewChapter OverviewChapter Overview

The Solar System and Some Early Astronomers

Rocketry and the Space Race

Chapter 7, Lesson 1

Lesson OverviewLesson OverviewLesson OverviewLesson Overview

The objects in the solar system The significant contributions of key

early astronomers

Chapter 7, Lesson 1

Quick WriteQuick WriteQuick WriteQuick Write

Why did Copernicus take so long to Why did Copernicus take so long to publish his important book?publish his important book?

Courtesy of Paul Almasy/Corbis

Chapter 7, Lesson 1

The Solar SystemThe Solar SystemThe Solar SystemThe Solar System

The solar system includes eight planets, their moons, and many other objects

Each of the planets revolvesrevolves, or circles in an orbit, around the sun

An orbitorbit is the path of a celestial body as it revolves around another body

In addition, each planet rotatesrotates, or spins on its axis

Courtesy of USGS Astrogeology Research Program

Chapter 7, Lesson 1

The SunThe SunThe SunThe Sun

The sun is the largest object in the solar system

It contains more than 99.8 percent of the total mass—the “stuff”—of the solar system

It is one of 100 billion stars in the Milky Way Galaxy

A galaxygalaxy is a huge mass of stars, gas, and dust clouds that exists in one area of space

Chapter 7, Lesson 1

The Planets and GravityThe Planets and GravityThe Planets and GravityThe Planets and Gravity

Galaxies and the solar system hold together because of gravity

GravityGravity is an invisible force that pulls all objects toward one another

The gravity of the sun holds the planets in place as they revolve around it

Likewise, the gravity of a planet holds its moons in place

Chapter 7, Lesson 1

MercuryMercuryMercuryMercury

Mercury is the smallest planet It’s also the one closest to the

sun It has a rocky, cratered surface Mercury revolves around the

sun every 88 Earth days Mercury rotates very slowly—it

takes 59 Earth days to make a rotation

Courtesy of USGS Astrogeology Research Program

Chapter 7, Lesson 1

VenusVenusVenusVenus

At 67 million miles from the sun, Venus is the planet closest to Earth

It’s also closest to Earth in terms of size

Its “year”—the time it takes to orbit around the sun— lasts 225 Earth days

Its “day” — the time it takes to make one rotation— is 243 Earth days

Courtesy of USGS Astrogeology Research Program

Chapter 7, Lesson 1

EarthEarthEarthEarth

Earth is the only planet to sustain life as far as we know

The clouds of Earth’s atmosphere help protect the planet from the sun’s radiation

More than 70 percent of Earth’s surface is covered with water

Earth makes a complete rotation every 24 hours

It completes an orbit around the sun every 365¼ days

Courtesy of NASA

Chapter 7, Lesson 1

Earth’s MoonEarth’s MoonEarth’s MoonEarth’s Moon

The moon has no atmosphere to protect it, and as a result, it has extreme temperatures and a rough surface

The moon revolves around Earth in an ellipticalelliptical orbit—an orbit shaped like an oval, not a circle

The moon orbits Earth in a little less than 28 days

The pull of the moon’s gravity creates tides on Earth

Courtesy of USGS Astrogeology Research Program

Chapter 7, Lesson 1

MarsMarsMarsMars

Mars, the Red Planet, is visible to the naked eye as a reddish dot in the sky

The color comes from the iron that makes up much of the planet’s core

Mars is covered with deserts, mountains, craters, and volcanoes

A day on Mars is a little longer than an Earth day: 24 hours, 37 minutes

Mars takes 687 Earth days to orbit the sun

Courtesy of USGS Astrogeology Research Program

Chapter 7, Lesson 1

JupiterJupiterJupiterJupiter

Jupiter is by far the largest planet It rotates quickly—about once every

10 hours This speed flattens it at the top and

makes it bulge in the middle Jupiter has windy, stormy weather Astronomers call Jupiter a “gas giant” The liquids of Jupiter’s outer core mix

with the gases in its atmosphere to form swift-moving belts of colorful clouds

Courtesy of NASA

Chapter 7, Lesson 1

SaturnSaturnSaturnSaturn

The second-largest planet in the solar system, Saturn is called the “ringed planet”

Its seven rings are made of icy chunks of rocks

The rings extend about 250,000 miles out from the planet

Like Jupiter, Saturn is a gas giant, and rotates quickly

It has stormy weather and 18 known moons

Courtesy of NASA

Chapter 7, Lesson 1

UranusUranusUranusUranus

Uranus, the third-largest planet, is another gas giant

Its main claim to fame is that it spins on its side

Scientists think that a long time ago, it may have collided with some other body that tilted it

Space probes of the 1970s discovered rings around Uranus, but they aren’t as impressive as Saturn’s

Courtesy of CALIFORNIA ASSOCIATION FOR RESEARCH IN ASTRONOMY / Photo Researchers, Inc.

Chapter 7, Lesson 1

NeptuneNeptuneNeptuneNeptune

Neptune is Uranus’s smaller twin

Neptune is the windiest planet in the solar system

Its winds blow up to 1,500 miles an hour

Like Jupiter, it has several dark storms, the largest of which is the Great Dark Spot

Neptune has eight moons

Courtesy of NASA

Chapter 7, Lesson 1

Pluto and the Dwarf PlanetsPluto and the Dwarf Planets Pluto and the Dwarf PlanetsPluto and the Dwarf Planets

Pluto is very small and very far away

Its career as a planet had a clearly marked beginning—and end

Clyde W. Tombaugh discovered Pluto on 18 February 1930

But on 24 August 2006 the International Astronomical Union voted to reclassify Pluto as a “dwarf planet”

Pluto and its moon Charon

Courtesy of NASA

Chapter 7, Lesson 1

Pluto and the Dwarf PlanetsPluto and the Dwarf Planets Pluto and the Dwarf PlanetsPluto and the Dwarf Planets

Pluto doesn’t dominate its moon, Charon, as a planet should

Besides, Pluto’s orbit is not fixed Sometimes it loops inside Neptune’s As a dwarf planet, Pluto has lots of

company Scientists have identified more than 40

dwarfs and they expect to find more

Chapter 7, Lesson 1

The AsteroidsThe AsteroidsThe AsteroidsThe Asteroids

An asteroidasteroid is a rocky and metallic object orbiting the sun

Most asteroids are in a belt that lies between Mars and Jupiter

Astronomers have found and catalogued more than 15,000 asteroids

Some asteroids are no bigger than pebbles The largest asteroid is Ceres, which has a

diameter of 623 milesCourtesy of NASA

Chapter 7, Lesson 1

CometsCometsCometsComets

A cometcomet is a small, odd-shaped body with a center of ice, rock, and frozen gas

Comets have elliptical orbits They draw close to the sun and

then fly far out into space After enough trips to the sun, the

ice melts, and a comet becomes just another rocky object in space

Courtesy of NASA

Chapter 7, Lesson 1

The Edgeworth-Kuiper BeltThe Edgeworth-Kuiper Belt The Edgeworth-Kuiper BeltThe Edgeworth-Kuiper Belt

The Edgeworth-Kuiper Belt is a vast region extending beyond Neptune

Scientists think there are millions of small, rocky or icy objects orbiting there

Pluto and Charon may be part of the belt NASA hopes to visit this region around

2010 with its Pluto-Kuiper Express

Chapter 7, Lesson 1

The Oort CloudThe Oort CloudThe Oort CloudThe Oort Cloud

The Oort Cloud is an immense spherical cloud

It surrounds the solar system and reaches about three light-years from the sun

A light-yearlight-year is the distance light travels in a year

Astronomers think this distance is the outer limit of the sun’s gravitational influence

The estimated mass of the Oort Cloud is 40 times that of Earth

Chapter 7, Lesson 1

Meteoroids, Meteorites, Meteoroids, Meteorites, and Meteorsand Meteors

Meteoroids, Meteorites, Meteoroids, Meteorites, and Meteorsand Meteors

A meteoroidmeteoroid is a piece of rock or metal that travels in space

Meteoroids are the smallest objects in the solar system

They may be chunks of rock melting away from comets as they approach the sun

A meteoritemeteorite is a meteoroid that lands on Earth’s surface

A meteormeteor is a meteoroid passing through Earth’s atmosphere, leaving a visible trail

Chapter 7, Lesson 1

AstronomyAstronomyAstronomyAstronomy

The history of astronomy is the story of humanity’s attempts to make sense of the heavens

All peoples have looked up to the skies and wondered about the movements of the sun, moon, and stars

As time passed, people learned that heavenly bodies obey the same laws that objects on Earth do

Chapter 7, Lesson 1

Contributions of PtolemyContributions of PtolemyContributions of PtolemyContributions of Ptolemy

The earliest widely known astronomer is Claudius Ptolemy, often known as Ptolemy of Alexandria

Ptolemy lived from around AD 85 until AD 165

Ptolemy is known not for his own work but for the way he combined other astronomers’ ideas

The system he came up with, called the Ptolemaic system, put Earth at the center of the universe

Courtesy of the Library of Congress

Chapter 7, Lesson 1

Contributions of PtolemyContributions of PtolemyContributions of PtolemyContributions of Ptolemy

Ptolemy was the first astronomer to make scientific maps of the heavens

He also developed a catalog listing 48 constellations

A constellationconstellation is a group of stars people think of as forming a picture in the sky

Scientists still use Ptolemy’s catalog

Courtesy of Clipart.com

Chapter 7, Lesson 1

Contributions of Ulug Bek Contributions of Ulug Bek Contributions of Ulug Bek Contributions of Ulug Bek

Ulug Bek was a mathematician and an astronomer

He had an observatoryobservatory, or a building designed to observe the stars, in what is today Uzbekistan

He made detailed observations and calculations

In 1437 Ulug Bek published a catalog of the stars (Zij-i Sultani) that gave the positions of 992 stars

Chapter 7, Lesson 1

Contributions of Ulug BekContributions of Ulug BekContributions of Ulug BekContributions of Ulug Bek

Ulug Bek also discovered several errors in Ptolemy’s calculations

No one had ever before questioned Ptolemy’s work

Using data he’d recorded in his observatory, Ulug Bek calculated the length of the year as 365 days, 5 hours, 49 minutes, and 15 seconds

He also produced data for the movements of the sun, the moon, and the planets

Chapter 7, Lesson 1

Contributions of Copernicus Contributions of Copernicus Contributions of Copernicus Contributions of Copernicus

Copernicus had access to records of the observations made over centuries, beginning with the ancient Greeks

He combined his study of those records with his own observations to come up with his own ideas

Courtesy of Erich Lessing/Art Resource, NY

The tower at FrauenburgCathedral where Copernicus conducted

his observations

Chapter 7, Lesson 1

Contributions of Copernicus Contributions of Copernicus Contributions of Copernicus Contributions of Copernicus

He never explained what inspired him to propose a heliocentric solar system

The Copernican system had fewer circles, and also had a unity and a logic that the Ptolemaic system lacked

Early heliocentric model

Courtesy of NASA

Chapter 7, Lesson 1

Contributions of KeplerContributions of KeplerContributions of KeplerContributions of Kepler

Johannes Kepler studied the work of Copernicus in Germany late in the 16th century

Kepler also improved on the Copernican theory

He showed that orbits of the planets weren’t perfect circles, but ellipses, or ovals

He also formulated three laws of planetary motion that astronomers still use today

Chapter 7, Lesson 1

Contributions of GalileoContributions of Galileo Contributions of GalileoContributions of Galileo

Galileo was among the first to appreciate the importance of the telescope

He read about the Dutch telescopes and soon started building his own

Galileo was also the first to use the telescope to methodically observe the sky

He was the first to see the moon’s craters

Courtesy of Bettmann/Corbis

Chapter 7, Lesson 1

Contributions of GalileoContributions of GalileoContributions of GalileoContributions of Galileo

Galileo also turned his telescope on Venus and saw that it goes through phases, just as Earth’s moon does

He spotted four “stars” near Jupiter and decided they were moons that circled that planet

For Galileo, this was further confirmation that Copernicus’s view of the solar system was correct

Courtesy of NASA

Chapter 7, Lesson 1

ReviewReviewReviewReview

The solar system includes eight planets, their moons, and many other objects

A galaxy is a huge mass of stars, gas, and dust clouds that exists in one area of space

Galaxies and the solar system hold together because of gravity

The gravity of the sun holds the planets in place as they revolve around it

Chapter 7, Lesson 1

ReviewReviewReviewReview

Earth is the only planet to sustain life as far as we know

On 24 August 2006 the International Astronomical Union voted to reclassify Pluto as a “dwarf planet”

A comet is a small, odd-shaped body with a center of ice, rock, and frozen gas

A meteoroid is a piece of rock or metal that travels in space

Chapter 7, Lesson 1

ReviewReviewReviewReview

Ptolemy was the first astronomer to make scientific maps of the heavens

In 1437 Ulug Bek published a catalog of the stars (Zij-i Sultani)

Copernicus never explained what inspired him to propose a heliocentric solar system

Kepler showed that orbits of the planets weren’t perfect circles, but ellipses, or ovals

Galileo was among the first to appreciate the importance of the telescope

Chapter 7, Lesson 1

SummarySummarySummarySummary

The objects in the solar systemThe significant contributions of key early

astronomers

Chapter 7, Lesson 1

Next….Next….Next….Next….

Done—the solar system and some early astronomers

Next—rocketry and the space race

V-2 Rocket

Courtesy of NASA