What is Earth's position among the planets, counting outward from the Sun?
AnswerThird
Earth is the third planet from the Sun, after Mercury and Venus.
Science · Facts & stats
Earth facts & stats
7 fact-checked facts about planet Earth, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
About what percentage of Earth's surface is covered by water?
AnswerAbout 71%
Oceans, seas, lakes and rivers cover roughly 71% of Earth's surface.
Going deeper
Which gas makes up most of Earth's atmosphere?
AnswerNitrogen
Nitrogen makes up about 78% of the air, oxygen about 21%.
What is Earth's inner core mostly made of?
AnswerIron and nickel
The inner core is a solid ball of mostly iron and nickel, kept solid by immense pressure.
About how long does sunlight take to reach Earth?
AnswerAbout 8 minutes
Light covers the 150 million km from the Sun in roughly 8 minutes and 20 seconds.
Expert level
About how old is Earth?
AnswerAbout 4.5 billion years
Radiometric dating shows Earth formed about 4.5 billion years ago; 13.8 billion is the universe's age.
Which layer of the atmosphere contains most of the ozone layer?
AnswerStratosphere
About 90% of atmospheric ozone sits in the stratosphere, where it absorbs ultraviolet light.
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