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About This Quiz
The Earth is home to all of us, but we probably know more about our literal homes than about our planetary one. People used to believe all sorts of wrong facts about the Earth: that it was flat, that it was the center of the universe, that it was 6,000 years old. We know now that humanity's tenure represents a small part of Earth's history, and that even we don't know everything about this great big ball of rock. Indeed, we know more about what's in space than about some of the less accessible places on Earth, like the depths of the ocean and certain borderline, unreachable caves and wildernesses.
This quiz will test your knowledge of this blue planet of ours. If you think you know the basics - where Earth is in the order of planets from the sun, how big it is, how many continents there are - you'll surely begin strong. However, only an expert will make it through the tougher questions, as we get into population growth, sea level changes, and when the last Ice Age ended.
Time to dredge up your history, geography, and economic knowledge, and get ready to impress even yourself!
To the nearest thousand, what is the circumference of the Earth?
15,000 miles
100,000 miles
25,000 miles
The Earth is 25,000 miles around at the equator.
40,000 miles
How old is the Earth?
4.5 billion years
The Earth is probably 4.5 billion years old, but the universe is more like 13.8 billion years old. The Earth came together out of heavier metals that orbited the sun and cooled into our rocky planet.
6 billion years
1 billion years
10,000 years
What shape is the Earth?
round
flat
oblate spheroid
The Earth is not actually perfectly spherical. It is mostly round, but slightly flatter at the top and bottom than around the equator, making it technically an oblate spheroid.
rhomboid
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How much of the Earth is covered by water?
100 percent
54 percent
71 percent
The Earth is 71 percent water. As sea levels rise, this number will go up a little.
18 percent
In the order of planets from the sun, where is Earth?
Second
Third
Here's a good mnemonic for remembering the order of the planets from the sun: My Very Efficient Memory Just Summed Up Nine. Of course, if you see Pluto as a planet, you turn this into "My Very Efficient Memory Just Summed Up Nine Planets."
Fourth
Fifth
How far from the sun is the Earth?
100 million miles
46 million miles
93 million miles
The Earth is 93 million miles from the sun, on average. Since its orbit is not perfectly round, this distance changes.
47 million miles
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How many moons does the Earth have?
one, obviously
nobody knows
The Earth definitely has one big visible moon that you can see from the planet's surface, but it is believed that there are many more moons, possibly thousands, which may be mostly very small and not visible.
none, that's a captured meteor
two
How far is the moon from the earth?
200,000 miles
240,000 miles
The moon is in an elliptical orbit, so the distance changes, but it is generally around 240,000 miles away from the earth.
100,000 miles
320,000 miles
What is the Earth's core made of?
iron and nickel
The earth's inner core is solid and mostly iron; the outer is an iron and nickel mix that is mostly liquid. The core is about 2,150 miles thick.
rock and titanium
rock and gold
gold and uranium
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What shape did Christopher Columbus think the Earth was?
pear shape
Contrary to popular belief, most people did not think the Earth was flat by the time Columbus set off. He thought it was probably pear-shaped and was keen to find out its circumference.
a very naughty shape that it would not be appropriate to say
flat
spherical
Who first figured out that the Earth is round?
Aristotle
Gallileo
Columbus
Pythagoras
Pythagoras first proposed the idea of a round planet. That didn't stop Galileo from being in serious trouble 2,000 years later for saying it.
What is the lowest place on Earth that isn't covered by water?
The Dead Sea
The Dead Sea is the lowest place on Earth. It is slowly evaporating, meaning its already high salt content is getting even higher.
The Mariana Trench
Lake Assal
Qattara Depression
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What is the Ring of Fire?
another name for the Northern Lights
volcanoes around the Pacific Rim
The Ring of Fire is an area around the Pacific Ocean where tectonic plates meet, prompting many earthquakes and volcanoes.
the volcanoes of Santorini
volcanoes around the Indian Ocean
What is the aurora borealis?
the Northern Lights
The aurora borealis is also known as the Northern Lights. It is caused by electrically-charged particles from the sun as they interact with the atmosphere.
the Southern Lights
the forests of Canda
it's when the poles switch place
How much of the Earth's land area is covered by forests?
92 percent
72 percent
7 percent
31 percent
Forests still cover about 1/3 of the Earth's land surface, accounting for 50 percent of the planet's plant activity.
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What temperature would the Earth be if there were zero greenhouse gases in the atmosphere?
-55 degrees Fahrenheit​
Greenhouse gases have raised the temperature of the planet from well below freezing to 59 degrees Fahrenheit, on average. Greenhouse gases have gone up as much as 50 percent, and there is a a lot of potential for this number to rise.
15 degrees Fahrenheit
102 degrees Fahrenheit
59 degrees Fahrenheit
What is the highest possible sea level above current levels, if all the ice on the planet melted?
50 feet
100 feet
220 feet
If all the ice on Earth were to melt, sea levels would rise about 220 feet. Most major coastal cities would be inundated, including entire countries, such as Bangladesh.
25 feet
How thick is the atmosphere?
300 miles
The atmosphere is 300 miles thick, but only the first few miles are breathable.
50 miles
100 miles
200 miles
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What is the driest place on Earth, besides the poles?
Gobi Desert
Sahara Desert
Atacama Desert
The driest place is the Atacama Desert which is on a high plateau in South America. Technically, Antarctica is drier, but it has a whole lot of ice.
Kalahari Desert
What is the coldest inhabited place on Earth?
Oymyakon, Russia
Oymyakon, Russia, is the coldest town on Earth that is continuously inhabited. It is a two-day drive from Yakutsk, and between October and March, it never gets above freezing.
McMurdo, Antarctica
Mount Everest's summit
Barrow, Alaska
How long does the Antarctic night last at the South Pole?
90 days
76 days
182 days
179 days
The polar night lasts 179 days. The area that doesn't see the sun for at least as long a period of time is bigger than just the pole, though, extending up into the 77th parallel and beyond.
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How fast is the Earth spinning?
100 mph
1,000 mph
The Earth spins about 1,000 mph at the surface. Technically, however, if you are on the equator, you are going a little bit faster than someone who is in the Arctic circle.
400 mph
1,500 mph
What percentage of the atmosphere is oxygen?
79 percent
12 percent
21 percent
About 21 percent of the atmosphere is oxygen. It is declining slightly which may be because air does escape a little into space, or because we're cutting down too many plants, which make oxygen. Most likely it is due to ocean acidification which harms ​phytoplankton that make most of our oxygen supply. If levels go below 18 percent, large mammals will not be able to live. Fortunately, we are a long way from that point.
42 percent
How old is the oldest life form on Earth?
4.28 billion years
There are microfossils that suggest life has been around nearly as long as the planet. Some people believe that life on our planet was seeded by a comet.
100 years
50 million years
850 million years
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How fast is the Earth going around the sun?
100,000 mph
67,000 mph
The Earth is going around the sun at 67,000 mph. Its orbit is defined by the fact that it goes exactly fast enough to not quite escape the sun's gravity.
15,000 mph
40,000 mph
What shape is the Earth's orbit?
round
oval
elliptical
The orbit of the Earth is indeed elliptical, which is like a long squashed oval. It means there are times we are closer to the sun and times we are further away.
round with a slight point
Which of these is not one of the three kinds of rock on the Earth: sedimentary, fossilized, metamorphic, igneous?
sedimentary
fossilized
Rocks can be sedimentary (laid down in layers), igneous (volcanic, i.e. formed by melting and reforming), or metamorphic (formed from the movement of Earth's crust but without melting). A life form can be fossilized, but a rock can't.
metamorphic
igneous
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What is an earthquake?
it's when a volcano is about to happen but there isn't enough energy
it's when tectonic plates hit each other
it's when tectonic plates break
it's when tectonic plates release pressure through various kinds of movement
An earthquake is what happens when two tectonic plates meet, separate, or go one over the other (known as subduction). The pressure of the two masses builds and builds, forming mountains or gorges when it happens slowly. When the pressure is too much, the plates suddenly slip, causing an earthquake.
What is a batholith?
a big crust of cooled magma
A batholith is what you get when a crust of magma cools fast enough to form a specific shape. Sometimes the batholith is harder than other rocks around it, so it remains intact while the other rocks are slowly eroded.
an extinct volcano
a place where an earthquake reveals the crust below
a place where a volcano will form one day
What is the longest mountain ridge on the planet?
Himalayas
Appalachians
Mid-Atlantic Ridge
The Mid-Atlantic Ridge is the longest mountain range, since the sea floor is no flatter than the land! It has many islands along its 10,000 mile length where the mountains poke out.
Andes
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What are the largest living structures on the planet?
coral reefs
honey fungus
Honey fungus have been measured at 2.4 miles long. They look like lots of little mushrooms, but are really one enormous organism.
whales
tapeworm
What is the tallest manmade structure on Earth?
Freedom Tower
Burj Khalifah
The Burj Khalifa was going to be called the Burj Dubai, but Dubai's economic crisis hit during construction and the structure had to be named after the guy who bailed out the project. It won't be the tallest building much longer, though.
Taipei 101
Petronas Towers
What is the oldest continuously inhabited settlement on earth?
Vilcabamba
Tenoichtitlan
Damascus
Damascus in Syria has been inhabited for 11,000 years, which means it predates our full move to a settled society. It has been through a lot of strife in that time and is currently mired in a very big and intractable war.
Ulaanbaatar
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How do plants make oxygen?
respiration
aspiration
photosynthesis
Photosynthesis is the way that plants make oxygen, by using the energy from the sun to transform carbon dioxide. They "breathe" in the CO2 and "breathe" out the O2.
biosynthesis​
You Got:
/35
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