Games Britannica Quizzes Britannica Menu History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture

Everything Earth

Question: What is Earth’s predominant environment?
Answer: Most of the world is covered by water, and most of that water is about 13,123 feet deep. Deep ocean is therefore the world’s most common environment.
Question: Which of these is not part of Earth’s crust?
Answer: The ionosphere is part of Earth’s atmosphere. The sima and sial are the upper crust, and the "Moho" discontinuity is at the base of the crust.
Question: How much of the Earth is covered with oceans?
Answer: About 71 percent, or nearly three-quarters, of our planet’s surface is covered with oceans.
Question: Who was the first person to orbit Earth?
Answer: On April 12, 1961, Yuri Gagarin became the first human to circle Earth in space. John Glenn followed on February 20, 1962.
Question: What is diatomaceous earth made of?
Answer: Diatomaceous earth is made from the fossilized remains of tiny marine organisms, particularly diatoms. It is used as a natural insecticide.
Question: What is the reflectivity of Earth’s surface called?
Answer: The albedo effect refers to the reflectivity of Earth’s surface. About 30 percent of shortwave radiation is bounced back into space by clouds, dust, snow, and ice.
Question: Earth revolves this many meters per second at the equator:
Answer: Earth revolves 1,532 feet per second (467 meters per second) at the equator.
Question: How old is sunlight by the time it reaches Earth?
Answer: It takes 8 minutes for sunlight to travel from the Sun to Earth.
Question: Which of these is not part of Earth?
Answer: The stratosphere is part of Earth’s atmosphere, but not part of Earth itself. The other three are the planet’s layers.
Question: What is the average surface temperature of Earth?
Answer: The average surface temperature on Earth is 57 ºF (14 ºC). It would be well below freezing were it not for greenhouse gases that trap warm air in the atmosphere.