introduction to the solar system

formation of the solar system

To figure out how the solar system formed, we need to put together what we have learned. There are two other important features to consider. First, all the planets orbit in nearly the same flat, disk-like region. Second, all the planets orbit in the same direction around the Sun. These two features are clues to how the solar system formed.

extrasolar planets

Since the early 1990s, astronomers have discovered other solar systems. A solar system has one or more planets orbiting one or more stars. We call these planets extrasolar planets, or exoplanets. They are called exoplanets because they orbit a star other than the Sun. As of June 2013, 891 exoplanets have been found. More exoplanets are found all the time. You can check out how many we have found at http://planetquest.jpl.nasa.gov/. We have been able to take pictures of only a few exoplanets. Most are discovered because of some tell-tale signs. One sign is a very slight motion of a star that must be caused by the pull of a planet. Another sign is the partial dimming of a stars light as the planet passes in front of it.

a giant nebula

Scientists think the solar system formed from a big cloud of gas and dust, called a nebula. This is the solar nebula hypothesis. The nebula was made mostly of hydrogen and helium. There were heavier elements too. Gravity caused the nebula to contract (Figure 25.6). As the nebula contracted, it started to spin. As it got smaller and smaller, it spun faster and faster. This is what happens when an ice skater pulls her arms to her sides during a spin move. She spins faster. The spinning caused the nebula to form into a disk shape. This model explains why all the planets are found in the flat, disk-shaped region. It also explains why all the planets revolve in the same direction. The solar system formed from the nebula about 4.6 billion years ago

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formation of the sun and planets

The Sun was the first object to form in the solar system. Gravity pulled matter together to the center of the disk. Density and pressure increased tremendously. Nuclear fusion reactions begin. In these reactions, the nuclei of atoms come together to form new, heavier chemical elements. Fusion reactions release huge amounts of nuclear energy. From these reactions a star was born, the Sun. Meanwhile, the outer parts of the disk were cooling off. Small pieces of dust started clumping together. These clumps collided and combined with other clumps. Larger clumps attracted smaller clumps with their gravity. Eventually, all these pieces grew into the planets and moons that we find in our solar system today. The outer planets Jupiter, Saturn, Uranus, and Neptune condensed from lighter materials. Hydrogen, helium, water, ammonia, and methane were among them. Its so cold by Jupiter and beyond that these materials can form solid particles. Closer to the Sun, they are gases. Since the gases can escape, the inner planets Mercury, Venus, Earth, and Mars formed from denser elements. These elements are solid even when close to the Sun.

the role of gravity

Planets are held in their orbits by the force of gravity. What would happen without gravity? Imagine that you are swinging a ball on a string in a circular motion. Now let go of the string. The ball will fly away from you in a straight line. It was the string pulling on the ball that kept the ball moving in a circle. The motion of a planet is very similar to the ball on a string. The force pulling the planet is the pull of gravity between the planet and the Sun. Every object is attracted to every other object by gravity. The force of gravity between two objects depends on the mass of the objects. It also depends on how far apart the objects are. When you are sitting next to your dog, there is a gravitational force between the two of you. That force is far too weak for you to notice. You can feel the force of gravity between you and Earth because Earth has a lot of mass. The force of gravity between the Sun and planets is also very large. This is because the Sun and the planets are very large objects. Gravity is great enough to hold the planets to the Sun even though the distances between them are enormous. Gravity also holds moons in orbit around planets.

the size and shape of orbits

Figure 25.4 shows the Sun and planets with the correct sizes. The distances between them are way too small. In general, the farther away from the Sun, the greater the distance from one planets orbit to the next. In Figure 25.5, you can see that the orbits of the planets are nearly circular. Plutos orbit is a much longer ellipse. Some astronomers think Pluto was dragged into its orbit by Neptune. Distances in the solar system are often measured in astronomical units (AU). One astronomical unit is defined as the distance from Earth to the Sun. 1 AU equals about 150 million km (93 million miles). Table 25.2 shows the distance from the Sun to each planet in AU. The table shows how long it takes each planet to spin on its axis. It also shows how long it takes each planet to complete an orbit. Notice how slowly Venus rotates! A day on Venus is actually longer than a year on Venus! Planet Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Average Distance from Sun (AU) 0.39 AU 0.72 1.00 1.52 5.20 9.54 19.22 30.06 Length of Day (In Earth Days) 56.84 days 243.02 1.00 1.03 0.41 0.43 0.72 0.67 Length of Year Earth Years) 0.24 years 0.62 1.00 1.88 11.86 29.46 84.01 164.8 (In

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changing views of the solar system

The Sun and all the objects that are held by the Suns gravity are known as the solar system. These objects all revolve around the Sun. The ancient Greeks recognized five planets. These lights in the night sky changed their position against the background of stars. They appeared to wander. In fact, the word planet comes from a Greek word meaning wanderer. These objects were thought to be important, so they named them after gods from their mythology. The names for the planets Mercury, Venus, Mars, Jupiter, and Saturn came from the names of gods and a goddess.

what is and is not a planet

Youve probably heard about Pluto. When it was discovered in 1930, Pluto was called the ninth planet. Astronomers later found out that Pluto was not like other planets. For one thing, what they were calling Pluto was not a single object. They were actually seeing Pluto and its moon, Charon. In older telescopes, they looked like one object. This one object looked big enough to be a planet. Alone, Pluto was not very big. Astronomers also discovered many objects like Pluto. They were rocky and icy and there were a whole lot of them. Astronomers were faced with a problem. They needed to call these other objects planets. Or they needed to decide that Pluto was something else. In 2006, these scientists decided what a planet is. According to the new definition, a planet must: Orbit a star. Be big enough that its own gravity causes it to be round. Be small enough that it isnt a star itself. Have cleared the area of its orbit of smaller objects. If the first three are true but not the fourth, then that object is a dwarf planet. We now call Pluto a dwarf planet. There are other dwarf planets in the solar system. They are Eris, Ceres, Makemake and Haumea. There are many other reasons why Pluto does not fit with the other planets in our solar system.

planets and their motions

Today we know that we have eight planets, five dwarf planets, over 165 moons, and many, many asteroids and other small objects in our solar system. We also know that the Sun is not the center of the universe. But it is the center of the solar system. Figure 25.3 shows our solar system. The planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Table 25.1 gives some data on the mass and diameter of the Sun and planets relative to Earth. Object Mass (Relative to Earth) Sun Mercury Venus Earth Mars Jupiter Saturn Uranus 333,000 Earths mass 0.06 Earths mass 0.82 Earths mass 1.00 Earths mass 0.11 Earths mass 317.8 Earths mass 95.2 Earths mass 14.6 Earths mass Diameter of Planet (Relative to Earth) 109.2 Earths diameter 0.39 Earths diameter 0.95 Earths diameter 1.00 Earths diameter 0.53 Earths diameter 11.21 Earths diameter 9.41 Earths diameter 3.98 Earths diameter Neptune 17.2 Earths mass

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the sun at the center of the universe

About 1,500 years after Ptolemy, Copernicus proposed a startling idea. He suggested that the Sun is at the center of the universe. Copernicus developed his model because it better explained the motions of the planets. Figure 25.2 shows both the Earth-centered and Sun-centered models. Copernicus did not publish his new model until his death. He knew that it was heresy to say that Earth was not the center of the universe. It wasnt until Galileo developed his telescope that people would take the Copernican

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earth at the center of the universe

The ancient Greeks thought that Earth was at the center of the universe, as shown in Figure 25.1. The sky had a set of spheres layered on top of one another. Each object in the sky was attached to one of these spheres. The object moved around Earth as that sphere rotated. These spheres contained the Moon, the Sun, and the five planets they recognized: Mercury, Venus, Mars, Jupiter, and Saturn. An outer sphere contained all the stars. The planets appear to move much faster than the stars, so the Greeks placed them closer to Earth. Ptolemy published this model of the solar system around 150 AD.

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instructional diagrams

description_image

The diagram shows the Solar System. The Sun and all the objects held by its gravity make up the solar system. There are eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, and Neptune. Pluto, Eris, Ceres, Make and Haumea are dwarf planets. The ancient Greeks believed Earth was at the center of the universe and everything else orbited Earth. Copernicus proposed that the Sun at the center of the universe and the planets and stars orbit the Sun. Planets are held by the force of gravity in elliptical orbits around the Sun. The solar system formed from a giant cloud of gas and dust about 4.6 billion years ago. This model explains why the planets all lie in one plane and orbit in the same direction around the Sun.

description_image

This diagram shows our Solar system. Our solar system consists of an average star we call the Sun, the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. It includes: the satellites of the planets; numerous comets, asteroids, and meteoroids; and the interplanetary medium. Jupiter is the largest planet and Saturn and Neptune have rings around them. Earth lies after Mercury and Venus. All the planets revolve around the sun. Pluto is the farthest and Mercury is nearest to the sun.

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There are eight planets in the Solar System. From closest to farthest from the Sun, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The first four planets are called terrestrial planets. They are mostly made of rock and metal, and they are mostly solid. The last four planets are called gas giants. This is because they are large planets that are mostly made of gas. Even though they are made of gas, they have much more mass than the terrestrial planets. Pluto had been called a planet since it was discovered in 1930, but in 2006 astronomers meeting at the International Astronomical Union decided on the definition of a planet, and Pluto did not fit. Instead they defined a new category of dwarf planet, into which Pluto did fit, along with some others. These small planets are sometimes called plutinos.

description_image

This diagram shows a few of the objects in our solar system. The first object shown in the upper row is the sun which is a star and is at the center of our solar system. The next three objects are the planets mercury, venus, earth. The objects in the second row are the moon which is the Earth's moon followed by the planets mars, jupiter and saturn. Jupiter is the largest planet. The planet saturn contains rings around it. Mercury is the planet closest to the sun in our solar system. Earth is the planet that we live on. The two planets not shown in this diagram are neptune and pluto.

questions

collection of many small objects beyond the orbit of Neptune

a. astronomical unit

-->  b. Kuiper belt

c. nebula

d. dwarf planet

e. solar system

f. asteroid belt

g. exoplanet

The planets appear to move

a. in the same direction as the stars

b. some with and some opposite the stars

c. in a circular motion

-->  d. sometimes with and sometimes opposite the stars

distance from Earth to the sun

-->  a. astronomical unit

b. Kuiper belt

c. nebula

d. dwarf planet

e. solar system

f. asteroid belt

g. exoplanet

The model that put the Sun at the center of the universe was proposed by

a. Aristotle

b. Galileo

-->  c. Copernicus

d. Ptolemy

star and the planets that orbit it

a. astronomical unit

b. Kuiper belt

c. nebula

d. dwarf planet

-->  e. solar system

f. asteroid belt

g. exoplanet

Extrasolar planets are found by

a. the wobble of a star on its axis

-->  b. the periodic dimming in of a star

c. being visible through a telescope

d. the excess gravity of a star

All of the planets in the solar system

-->  a. lie in the same plane

b. are made mostly of rocks and metals

c. rotate in the same direction

d. all of these

collection of many small objects between the orbits of Mars and Jupiter

a. astronomical unit

b. Kuiper belt

c. nebula

d. dwarf planet

e. solar system

-->  f. asteroid belt

g. exoplanet

planet that orbits a star other than the sun

a. astronomical unit

b. Kuiper belt

c. nebula

d. dwarf planet

e. solar system

f. asteroid belt

-->  g. exoplanet

The force of gravity between objects depends on their mass and ____

a. acceleration

-->  b. distance apart

c. gravitational potential energy

d. density

planet such as Pluto

a. astronomical unit

b. Kuiper belt

c. nebula

-->  d. dwarf planet

e. solar system

f. asteroid belt

g. exoplanet

giant cloud of gas and dust

a. astronomical unit

b. Kuiper belt

-->  c. nebula

d. dwarf planet

e. solar system

f. asteroid belt

g. exoplanet

If you know a planets orbit you can determine its approximate distance from the Sun.

-->  a. true

b. false

The planets in order from the Sun are Mars, Venus, Earth, Mercury, Saturn, Uranus, Jupiter and Neptune.

a. true

-->  b. false

The orbits of the planets are circular.

a. true

-->  b. false

One astronomical unit is the distance from Earth to Sun.

-->  a. true

b. false

All of the planets in the solar system rotate in the same direction.

a. true

-->  b. false

The planets in our solar system were named for Greek gods and goddesses.

-->  a. true

b. false

We now know that the sun is the center of the universe.

a. true

-->  b. false

Scientists think that our solar system formed from an asteroid belt.

a. true

-->  b. false

The planets formed when pieces of matter collided and clumped together.

-->  a. true

b. false

Our solar system contains five dwarf planets.

-->  a. true

b. false

The planet closest to the sun is Venus.

a. true

-->  b. false

The planet with the greatest mass and diameter is Saturn.

a. true

-->  b. false

Planets farther from the sun have orbits that are farther apart.

-->  a. true

b. false

The orbits of the planets are nearly circular.

-->  a. true

b. false

Our sun is the only star that has planets revolving around it.

a. true

-->  b. false

Our solar system includes

a. galaxies.

-->  b. asteroids.

c. black holes.

d. constellations.

The early Earth-centered model of the universe was proposed by

a. Galileo.

-->  b. Ptolemy.

c. Copernicus.

d. none of the above

The planet that is most similar to Earth in mass and diameter is

a. Mars.

-->  b. Venus.

c. Jupiter.

d. Mercury.

Which statement is true about the inner planets of our solar system?

a. They formed before the sun formed.

-->  b. They formed from dense elements.

c. They include Mars and Jupiter.

d. They have very long years.

All planets of our solar system orbit the sun

a. in the same plane.

b. at the same speed.

c. in the same direction.

-->  d. two of the above

How long the day lasts on a planet depends on its

a. distance from the sun.

b. speed of revolution.

-->  c. speed of rotation.

d. length of orbit.

To be a planet, an object must

a. be big enough that its own gravity makes it round.

b. have cleared its path of smaller objects.

c. orbit a star.

-->  d. all of the above

diagram questions

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Which label refers to the Mars?

a. F

-->  b. A

c. M

d. X

question_image

Which label shows Jupiter?

a. M

-->  b. U

c. Y

d. W

question_image

Identify Pluto

a. K

b. P

c. S

-->  d. Y

question_image

Which letter refers to a dwarf planet?

a. C

b. P

c. T

-->  d. Y

question_image

Select the biggest planet of the Solar System.

a. H

b. P

c. V

-->  d. K

question_image

Which planet has 2 rings around it?

a. J

b. Y

-->  c. P

d. D

question_image

Identify the Earth in this picture

a. A

b. P

-->  c. Y

d. L

question_image

Which label refers to the Earth?

-->  a. Y

b. S

c. P

d. X

question_image

Which label indicates Saturn in the solar system diagram?

a. S

b. L

-->  c. D

d. M

question_image

What is the biggest body of the Solar System?

a. VENUS

-->  b. SUN

c. JUPITER

d. URANUS

question_image

Which planet is furthest from the sun?

a. JUPITER

b. MERCURY

c. NEPTUNE

-->  d. PLUTO

question_image

What is the Name of the Planet Labeled V?

a. MARS

b. URANUS

c. EARTH

-->  d. SATURN

question_image

Which label indicates Mars in the solar system diagram?

-->  a. K

b. E

c. S

d. N

question_image

Which planet is Neptune?

a. J

-->  b. R

c. L

d. S

question_image

With which letter is Saturn represented?

-->  a. L

b. J

c. H

d. R

question_image

Which is the second largest planet?

-->  a. L

b. R

c. J

d. H

question_image

Identify Saturn in this picture

a. D

b. T

c. R

-->  d. U

question_image

Which planet is Neptune?

-->  a. E

b. R

c. A

d. J

question_image

Which planet lies between A and H?

-->  a. D

b. U

c. J

d. R

question_image

Which label refers to Mars?

a. E

b. A

-->  c. H

d. F

question_image

Which label represents the sun?

-->  a. F

b. E

c. Y

d. H

question_image

What Planet is labelled at A?

a. JUPITER

-->  b. EARTH

c. SATURN

d. VENUS

question_image

Identify Mars in the following image:

a. F

b. S

c. C

-->  d. T

question_image

Where is the Earth?

-->  a. A

b. J

c. C

d. P

question_image

Which planet is closest to the sun?

-->  a. Y

b. S

c. T

d. J

question_image

Which planet is the 3rd from the sun?

-->  a. A

b. J

c. T

d. C

question_image

What tag identifies earth?

a. U

-->  b. N

c. R

d. C

question_image

Which label represents Saturn?

a. S

b. N

c. U

-->  d. C

question_image

Which letter represents earth?

a. R

b. U

-->  c. N

d. C

question_image

What is the fifth farthest planet from the Sun?

a. D

-->  b. L

c. C

d. U

question_image

Identify D

a. JUPITER

b. NEPTUNE

-->  c. MERCURY

d. MARS

question_image

Which label refers to the Earth?

-->  a. Y

b. D

c. R

d. X

question_image

Identify Saturn

a. J

b. S

c. X

-->  d. H

question_image

Which label shows Jupiter?

a. H

-->  b. S

c. L

d. N

question_image

Which is the planet with the higher ground temperatures?

a. S

b. N

c. Y

-->  d. C

question_image

How many planets there are in the diagram below?

a. 10

-->  b. 8

c. 7

d. 9

question_image

Identify the planet closest to the sun, based on the diagram presented.

a. Pluto

b. Jupiter

-->  c. Mercury

d. Earth

question_image

What planet comes after Jupiter?

-->  a. Saturn

b. Mars

c. Pluto

d. Neptune

question_image

Which planet is closest to the sun?

a. Earth

-->  b. Mercury

c. Venus

d. Mars

question_image

How many planets are shown in the figure?

a. 7

b. 10

c. 8

-->  d. 9

question_image

How many planets you can see?

a. 5

-->  b. 9

c. 8

d. 10

question_image

In the diagram, which planet would take the longest to travel its orbit around the sun?

a. Earth

b. Saturn

c. Mercury

-->  d. Pluto

question_image

Which planet has the longest year?

a. Saturn

-->  b. Neptune

c. Pluto

d. Uranus

question_image

Which planet is the smallest?

a. Jupiter

b. Uranus

-->  c. Pluto

d. Earth

question_image

Which planet is bigger than Saturn?

a. Saturn is the biggest

b. Neptune

-->  c. Jupiter

d. Uranus

question_image

How many planets are shown in the diagram?

a. 4

b. 5

c. 7

-->  d. 9

question_image

How many planets does the solar system have according to the diagram?

a. 10

-->  b. 9

c. 7

d. 8

question_image

What is the biggest planet on the solar system?

-->  a. Jupiter

b. Uranus

c. Saturn

d. Neptune

question_image

What will be the largest planet if Jupiter is removed?

a. Neptune

b. Mars

-->  c. Saturn

d. Uranus

question_image

Which of these planets orbits closest to the sun? A) Neptune B) Earth C) Saturn D) Venus

a. A) Neptune

-->  b. D) Venus

c. C) Saturn

d. B) Earth

question_image

Which planet follows earth in the solar system?

a. saturn

b. mercury

-->  c. mars

d. venus

question_image

How many planets are in our solar system other than the Earth?

a. 10

b. 11

c. 9

-->  d. 8

question_image

Mercury is the...

a. farthest from earth

b. largest planet

c. coldest planet

-->  d. hottest planet

question_image

The Earth is among the 9 planets of the Solar System. The center of the Solar System is which structure or planet?

-->  a. Sun

b. Mercury

c. Pluto

d. Asteroids

question_image

From the diagram, identify the largest planet.

a. Sun

-->  b. Jupiter

c. Earth

d. Saturn

question_image

This is the biggest planet in the solar system.

a. Saturn

b. Pluto

c. Earth

-->  d. Jupiter

question_image

Which planet is closest to the sun?

a. Earth

-->  b. Mercury

c. Venus

d. Pluto

question_image

Which planet lies between Venus and mars?

a. uranus

b. neptune

c. pluto

-->  d. earth

question_image

How many planets does the solar system have?

a. 7

b. 10

-->  c. 9

d. 8

question_image

Name the planets in the solar system

a. mares

b. plito

-->  c. sun, mercury, venus, earth, mars, jupiter, sturn, uranus, neptune, pluto

d. saturne

question_image

Which is the biggest planet in the Solar System?

-->  a. Jupiter

b. Uranus

c. Venus

d. Earth

question_image

Identify the planet farthest from the sun.

a. Venus

b. Saturn

-->  c. Pluto

d. Neptune

question_image

Which planet in the solar system is the coldest one?

a. Earth

b. Mercury

c. Mars

-->  d. Pluto

question_image

Which planet is between Saturn and Neptune?

a. Mars

b. Jupiter

c. Neptune

-->  d. Uranus

question_image

Which planet is located the closest to the sun?

a. Venus

b. Earth

-->  c. Mercury

d. Pluto

question_image

How many planets are closer to the sun than earth?

a. 9

b. 4

-->  c. 2

d. 3

question_image

How many planets there are in the diagram below?

a. 7

b. 1

c. 9

-->  d. 8

question_image

Name the planets.

-->  a. Our Solar System has eight planets which orbit the sun. In order of distance from the sun they are; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto, which until recently was considered to be the farthest planet, is now classified as a dwarf planet.

b. Pluto is no longer considered a planet.

c. Our Solar System has 9 planets which orbit the sun.

d. Our Solar System has 7 planets which orbit the sun.

question_image

Which planet is between Venus and Mars?

a. Saturn

-->  b. Earth

c. Jupiter

d. Uranus

question_image

Identify the planet that reflects the sun's light on to Earth.

a. Venus

-->  b. Moon

c. Jupiter

d. Satrum

question_image

What planet orbits between Venus and Mars?

-->  a. Earth

b. Mercury

c. Neptune

d. The Moon

question_image

Which planet is between Jupiter and Earth?

a. Saturn

b. Uranus

-->  c. Mars

d. Venus

question_image

How many planets are between the Sun and Jupiter?

-->  a. 4

b. 3

c. 5

d. 9

question_image

How many planets are nearer to the sun than Earth is?

a. 1

b. 3

-->  c. 2

d. 4

question_image

Which among the planets contains the coldest of temperatures?

a. Uranus

b. Mercury

c. Saturn

-->  d. Pluto

question_image

What planet is closest to Pluto?

-->  a. Neptune

b. Mercury

c. Earth

d. Mars

question_image

Which planet takes the least amount of time to orbit the sun once?

a. Earth

-->  b. Mercury

c. Pluto

d. Jupiter

question_image

How many planets are in-between the Earth and the sun?

a. 1

b. 4

-->  c. 2

d. 3

question_image

How many planets are taking years to complete a revolution?

-->  a. 5

b. 3

c. 4

d. 6

question_image

How long does it take for Jupiter to circle the sun?

a. 225 Days

-->  b. 12 Years

c. 365 Days

d. 12 Days

question_image

How many planets are shown in the picture?

-->  a. 9

b. 5

c. 10

d. 7

question_image

Name the planets

a. Ceres

-->  b. Solar System

c. Pluto

d. moon

question_image

This planet is closest to the sun.

-->  a. Mercury

b. Earth

c. Venus

d. Pluto

question_image

Which planet lies in between Uranus and Pluto?

a. earth

b. mars

c. saturn

-->  d. neptune

question_image

Which plant orbits between Earth and Jupiter?

-->  a. Mars

b. Neptune

c. Mercury

d. Saturn

question_image

How many planets are in the diagram?

a. 10

b. 8

c. 7

-->  d. 9

question_image

How many planets can be seen in the above diagram?

a. 7

b. 9

c. 10

-->  d. 8

question_image

Which planet is between Venus and Mars?

a. Saturn

b. Jupiter

c. Mercury

-->  d. Earth

question_image

Which planet is known as the dwarf planet?

a. Earth.

b. Venus.

c. Mercury.

-->  d. Pluto.

question_image

Which planet is between Venus and Mars?

a. Saturn

-->  b. Earth

c. Jupiter

d. Uranus

question_image

Which planet is the hottest one in the solar system?

-->  a. Mercury

b. Mars

c. Pluto

d. Venus

question_image

What planet is the closest to the sun?

a. Neptune

-->  b. Mercury

c. Jupiter

d. Uranus

question_image

Which of the planets is farthest from the sun?

a. Saturn

b. Uranus

-->  c. Pluto

d. Neptune

question_image

From the diagram, how many planets are nearer to the sun than Earth?

a. 4

b. 3

c. 1

-->  d. 2

question_image

How many planets are farther from the sun than the earth?

a. 7

b. 5

-->  c. 6

d. 2

question_image

Which planet has the hottest surface?

-->  a. Mercury

b. Neptune

c. Mars

d. Saturn

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Which planet lies between Jupiter and Uranus?

a. Venus

b. Earth

c. Mercury

-->  d. Saturn

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From the diagram, identify which is the largest planet.

a. Earth

b. Saturn

-->  c. Jupiter

d. Neptune

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Which is the largest planet in our solar system?

a. mars

b. mercury

c. neptune

-->  d. jupiter

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Which planet is largest?

a. Mercury

-->  b. Jupiter

c. Earth

d. Mars

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How many planets are shown?

a. 6

b. 9

-->  c. 8

d. 7

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How many planets does the solar system have according to the diagram?

a. 10

b. 9

-->  c. 8

d. 7

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What is nuclear fusion?

-->  a. It is a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.

b. An atmosphere is the gases that surround a planet.

c. Made mostly of hydrogen and helium.

d. Different materials in its region of space collided.

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What is the largest planet if there is no Jupiter?

a. Earth

b. Uranus

c. Mars

-->  d. Saturn

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Which planet has rings?

a. earth

-->  b. saturn

c. saturn

d. pluto

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Which of the planets is the largest; which is the smallest?

a. Jupiter; Neptune

b. Saturn; Mercury

c. Saturn; Pluto

-->  d. Jupiter; Pluto

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Which planet in the diagram is the largest?

a. Earth

b. Uranus

c. Saturn

-->  d. Jupiter

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How many of the planets are surrounded by rings?

a. 4

b. 1

-->  c. 2

d. 3

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How many planets are in our solar system?

a. 6

b. 8

c. 7

-->  d. 9

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Which among the planets is the biggest?

-->  a. Jupiter

b. Uranus

c. Saturn

d. Venus

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Which planet do we live on?

a. Neptune

b. Mercury

-->  c. Earth

d. Saturn

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Which planet is the largest?

a. Venus

b. Neptune

-->  c. Jupiter

d. Earth

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Which planet in diagram does not have a ring?

-->  a. Mercury

b. Uranus

c. Saturn

d. Neptune

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How many of the planets in the diagram have rings?

a. 9

b. 0

c. 4

-->  d. 3

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What is the biggest planet in the solar system as shown in the picture?

a. Saturn

b. Venus

c. Earth

-->  d. Jupiter

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Which planet is between Venus and Mars?

a. Saturn

-->  b. Earth

c. Uranus

d. Jupiter

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Which is the largest terrestrial planet?

a. Venus

b. Mars

-->  c. Earth

d. Mercury

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Which planet follows earth?

a. venus

-->  b. mars

c. saturn

d. neptune

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How many planets in the solar system has rings around it?

a. 2

b. 3

c. 4

-->  d. 1

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How many planets shown?

a. 9

b. 15

-->  c. 8

d. 10

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How does the temperature of Mercury compare to Earth?

a. Colder

b. Wetter

-->  c. Hotter

d. The same

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Which planet comes after Jupiter away from the sun?

a. Neptune

b. Mars

-->  c. Saturn

d. Uranus

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This planet is known for its many rings.

a. Neptune

-->  b. Saturn

c. Uranus

d. Jupiter

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How many planets are in the image?

-->  a. 9

b. 11

c. 10

d. 12

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What planet has rings around it?

-->  a. Saturn

b. Uranus

c. Venus

d. Mars

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How many planets are there according to the diagram?

a. 8

b. 10

c. 11

-->  d. 9

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How many planets are there?

-->  a. 9

b. 11

c. 10

d. 8

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Which planet has prominent rings?

a. Venus

-->  b. Saturn

c. Neptune

d. Mars

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What is the largest planet?

-->  a. Jupiter

b. Mars

c. Venus

d. Neptune

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What planet is between Jupiter and Uranus?

a. Mars

b. Neptune

c. Ceres

-->  d. Saturn

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How many dwarf planets are in the new solar system?

-->  a. 3

b. 2

c. 1

d. 4

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How many planets there are in the diagram below?

-->  a. 8

b. 3

c. 7

d. 4

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Which is the planet with the highest ground temperatures?

a. Earth

b. Eris

-->  c. Mercury

d. Jupiter

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Which planet is the closest to the Sun?

a. Earth

b. Jupiter

-->  c. Mercury

d. Saturn

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Which planet is between Venus and Mars?

a. Jupiter

b. Saturn

c. Uranus

-->  d. Earth

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How many orbits does the earth make around the sun in one year?

a. 3

-->  b. 1

c. 4

d. 2

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Which planet is nearest the sun?

-->  a. Mercury

b. Earth

c. Venus

d. Mars

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How many planets are located between the Sun and the Earth?

a. 4

-->  b. 2

c. 1

d. 3

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How many planets have rings?

a. 3

b. 4

c. 2

-->  d. 1

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In between Mars and Jupiter is what structure?

-->  a. Asteroid Belt

b. Uranus

c. Saturn

d. Earth

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Which planet is the closest to the sun?

a. Neptune

b. Saturn

-->  c. Mercury

d. Earth

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Which is the biggest planet in the solar system?

-->  a. Jupiter

b. Earth

c. Mercury

d. Venus

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Which planet's orbit is closest to the Sun?

-->  a. Mercury

b. Neptune

c. Jupiter

d. Venus

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What is the biggest planet in the image?

-->  a. Jupiter

b. Saturn

c. Uranus

d. Sun

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What planet is closest to the sun?

a. Pluto

b. Jupiter

c. Earth

-->  d. Mercury

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How many planets are there between the sun and Saturn?

a. 9

b. 3

-->  c. 5

d. 2

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How many planets are there in the solar system according to the diagram?

a. 11

b. 8

c. 10

-->  d. 9

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If the earth was moved further away from the sun how would our climate be affected?

a. It would not change.

b. We would be nearer the sun.

-->  c. It would be colder.

d. It would be warmer.

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Which among the planets is the farthest from the sun?

a. Uranus

b. Venus

c. Neptune

-->  d. Pluto

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Which planet comes after Venus?

a. jupiter

-->  b. earth

c. mars

d. uranus

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This is the only planet known with living things.

a. Uranus

b. Jupiter

c. Ceres

-->  d. Earth

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Which of the following is the last planet of our solar system?

a. Uranus

-->  b. Neptune

c. Mercury

d. Pluto and Charon

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Which is the closest planet to the sun?

a. venus

b. mars

c. saturn

-->  d. mercury

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Which planet is the closest to the sun?

a. neptune

b. venus

c. mars

-->  d. mercury

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How many planets are between the Sun and the Earth?

a. 1

b. 3

-->  c. 2

d. 4

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This philosopher believed that the Earth was the Center of the Universe.

-->  a. Ptolemy

b. Aristotle

c. Prometheus

d. Copernicus

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Which planet is between Venus and Mars?

a. Ceres

-->  b. Earth

c. Jupiter

d. Saturn

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Which planet has living beings in it?

a. Mercury

b. Venus

-->  c. Earth

d. Mars

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Which planet is between Mercury and Earth?

-->  a. Venus

b. Jupiter

c. Mars

d. Saturn

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How many planets are there?

-->  a. 8

b. 6

c. 7

d. 9

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How many planets in the solar system have visible rings?

a. 2

-->  b. 1

c. 4

d. 3

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Which planet takes the longest to orbit around the sun?

a. Earth

-->  b. Neptune

c. Jupiter

d. Mercury

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Which planet is known for the rings of debris surrounding it?

-->  a. Saturn

b. Jupiter

c. Neptune

d. Uranus

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Which planet is located closest to the Sun?

a. Mars

b. Venus

c. Earth

-->  d. Mercury

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Which planet lies between Jupiter and Neptune?

-->  a. Saturn

b. Mercury

c. Mars

d. Venus

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How many planets are between Mercury and Neptune?

a. 2

b. 4

c. 8

-->  d. 6

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How many planets are there in the solar system without the dwarf planet Pluto?

a. 10

b. 9

-->  c. 8

d. 7

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What is shown in the picture?

a. Nuclear Energy

-->  b. Solar System

c. Photosynthesis

d. Life Cycle

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Which planet comes after Jupiter away from the sun?

a. Neptune

b. Mars

-->  c. Saturn

d. Uranus

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Which planet is closer than Earth is to the sun?

a. Saturn

b. Uranus

-->  c. Venus

d. Mars

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How many planets are shown in the picture?

a. 6

-->  b. 8

c. 7

d. 9

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What is the 5th closest planet to the sun in the solar system?

a. Mars

-->  b. Jupiter

c. Saturn

d. Mercury

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How many planets are between Earth and the Sun?

a. 3

b. 4

-->  c. 2

d. 1

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How many planets are shown in the diagram?

-->  a. 8

b. 9

c. 7

d. 6

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Approximately how long does it take the Earth the make a full rotation around the sun?

a. 366 days

-->  b. 365.25 days

c. 325.5 days

d. 240 days

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Which planet has the longest year compared to one year on the Earth? Explain your answer.

a. Neptune has the longest year because it is furthest from the Earth.

b. Mars has the longest year because it has the slowest orbit.

c. Mercury has the longest year because it is closest to the Sun.

-->  d. Neptune has the longest year because it is furthest from the Sun.

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Which sphere orbits around the Earth?

a. Venus

-->  b. Moon

c. Sun

d. Mars

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What planet has rings around it?

a. Mars

-->  b. Saturn

c. Mercury

d. Neptune

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Which is the closest planet to the sun?

a. venus

b. earth

-->  c. mercury

d. saturn

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How many planets do you see on this picture?

-->  a. 8

b. 9

c. 10

d. 7

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How many planets have rings?

a. 5

-->  b. 2

c. 3

d. 4

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What is the furthest planet away from the sun?

a. saturn

-->  b. Neptune

c. earth

d. jupiter

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Which of these planets has prominent rings?

a. Jupiter

b. Mercury

c. Mars

-->  d. Saturn

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Which planet has rings around it?

a. Jupiter

b. Mercury

c. Earth

-->  d. Saturn

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Which planet is between Venus and Mars?

a. Mars

b. Mercury

-->  c. Earth

d. Jupiter

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How many planets are there?

a. 11

b. 10

c. 8

-->  d. 9

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Name the planets.

a. Asteroids

b. Comets

-->  c. Our Solar System has eight planets which orbit the sun. In order of distance from the sun they are; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto, which until recently was considered to be the farthest planet, is now classified as a dwarf planet.

d. Nebula

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Which planet is on its side due to the unusual position of its rings?

a. Venus

b. Saturn

c. Neptune

-->  d. Uranus

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How many planets are in the image?

a. 6

b. 7

-->  c. 8

d. 9

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Which of these planets takes the longest amount of time to orbit the sun?

a. Mars

b. Mercury

-->  c. Neptune

d. Jupiter

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How many planets are bigger than Mars?

-->  a. 6

b. 5

c. 1

d. 8

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How many planets have rings?

a. 5

b. 4

-->  c. 2

d. 6

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This is known as a big cloud of dust composed generally of helium and hydrogen.

a. Exoplanet

-->  b. Nebula

c. Star

d. Galaxy

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This is the biggest planet in the solar system.

a. Mars

b. Saturn

c. Earth

-->  d. Jupiter

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What planet is closest to the sun?

a. venus

b. earth

-->  c. mercury

d. pluto

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Identify earth

a. N

-->  b. R

c. M

d. L

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Identify earth

a. T

-->  b. A

c. J

d. F