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Can You Answer These Basic Questions About Earth?

There's a lot we don't know about our home planet and solar system.

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Ultra Realistic Earth from Space 3d illustrationДмитрий Ларичев/Getty Images

How well do you know your home planet?

Assuming you live on planet Earth. If not, we come in peace. Test your home planet knowledge with these questions. You’d be surprised how little we all know about this rock we call home. You might just need these crazy facts about Earth you never learned in school to ace this one.

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earth disappearing things changing alxpin/Getty Images

Which planet(s) is/are in between Earth and the sun?

A. Mercury and Mars

B. Mercury and Venus

C. Just Mercury

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The Jupiter from space showing all they beauty. Extremely detailed image, including elements furnished by NASA. Other orientations and planets available.Vadim Sadovski/Shutterstock

B. Mercury and Venus

The order of our planets from the sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Love planets? Check out these NASA discoveries that changed science textbooks.

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Yellow tape measureDarko Kovacevic/Shutterstock

How big is Earth’s radius?

A. 4,000 miles

B. 5,000 miles

C. 6,000 miles

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earths radius web2000ra/Getty Images

A. 4,ooo miles

The Earth’s radius is 3,958.8 miles long, and its circumference is 24,873.6 miles. Who knew? If you like this quiz, you’ll love these world facts you didn’t know you wanted to know.

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solar-systemVadim Sadovski/Shutterstock

How does Earth’s size compare to the other planets?

A. The third-largest

B. The fifth-largest

C.  The second smallest

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Solar systemadventtr/Getty Images

B. The fifth-largest

At least in regards to the planets in our solar system. The planets in order from largest to smallest are Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, and Mercury. And then there’s the dwarf planet, Pluto. If you were in school before 2006, you probably learned that Pluto was the 9th planet, but just like these other facts you learned in school that are no longer true, you’re going to have to update your knowledge about that one.

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Crowd of people walking on a street in New York City blvdone/Shutterstock

About how many people currently live on Earth?

A. 7 billion

B. 7.3 billion

C. 7.5 billion

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Crowd walking on global mapOrbon Alija/Getty Images

C. 7.5 billion

Although technically this number changes every day, currently the Earth’s population is over 7.5 billion people, all sharing this one small planet. With all those people it’s no wonder the planet is in trouble. Here are 50 powerful photos that prove that the Earth still needs our help.

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planting treeslovelyday12/Getty Images

When do scientists think life began on Earth?

A. 3.8 billion years ago

B. 4.5 billion years ago

C. 6 billion years ago

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Stromatolites in Shark Bay Western Australiachameleonseye/Getty Images

A. 3.8 billion years ago

Life may have appeared 3.8 billion years ago, but according to scientists, Earth is at least 4.5 billion years old. All this time later, there are still places on this planet that are unmapped!

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Save the earth concept, Woman hands is holding mockup the global on tree leave background.K.D.P/Shutterstock

How long have we been calling this planet Earth?

A. At least 700 years

B. At least 1,000 years

C. At least 2,000 years

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World globe, Manhattan, NY, USAMedioimages/Photodisc/Getty Images

B. At least 1,000 years

Earth is the only planet not named after a Greek or Roman god or goddess. Here are 24 more astronomy facts you didn’t learn in school.

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Shetland Islands, Scotland.Flavio Vallenari/Getty Images

Earth is a terrestrial planet. What does that mean?

A. It is made mostly of rock.

B. It has dirt on its surface.

C. It has an atmosphere that can sustain life.

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Photo of Preikestolen, Pulpit Rock at Lysefjord in Norway. Aerial view.Dmytro Kosmenko/Getty Images

A. It is made mostly of rock.

The other terrestrial planets are Mercury, Venus, and Mars. Enjoy Earth facts? You’ll love the biggest unsolved mysteries on planet Earth.

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texture layers of earthKichigin/Getty Images

How many layers does Earth have?

A. Three

B. Four

C. Five

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Planet Earth and Sun.buradaki/Getty Images

B. Four

They are the inner core, the outer core, the mantle, and the crust.

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Thermometers on red and blue backgroundsMicroStockHub/Getty Images

How hot can the Earth’s core get?

A. 8,600 degrees Fahrenheit

B. 9,200 degrees Fahrenheit

C. 9,800 degrees Fahrenheit

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Structure core Earth. Structure layers of the earth. The structure of the earth's crust. Earth cross section in space view. Elements of this image furnished by NASA. 3D renderingRost-9D/Getty Images

C. 9.800 degrees Fahrenheit

A more recent study suggests that it could be even hotter, perhaps even as hot as the sun! Confused by this measurement? Here’s why Americans use Fahrenheit instead of Celsius.

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Space, Sun and planet Earth. Western hemisphere. This image elements furnished by NASA.buradaki/Shutterstock

How long is Earth’s orbit around the sun?

A. More than 580 million miles

B. More than 106 miles

C. More than 84 million miles

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Graphic illustration of the Earth and the sunegal/Getty Images

A. More than 580 million miles

The Earth’s orbit is 584 million miles long. Even crazier than that number? The truth behind the distance between the Earth and the sun.

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earth atmosphere carbon neutral Rawf8/Getty Images

What makes up nearly 80 percent of the Earth’s atmosphere?

A. Oxygen

B. Nitrogen

C. Carbon dioxide

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nitrogen earthMarcelC/Getty Images

B. Nitrogen

Near Earth’s surface, the atmosphere is 78 percent nitrogen, 21 percent oxygen, and 1 percent other gases like carbon dioxide, argon, and neon. Next, enjoy these surprising Earth Day statistics.

Isabel Roy
Isabel Roy is the newsletter editor at Reader’s Digest. She writes and reports on home, culture, and general interest stories. She graduated from the University of Wisconsin La Crosse in 2017 with a B.A. in Rhetoric and Writing.