Facts - 50 Amazing Earth Facts to Know - Part I

We live on a sphere of extremes and oddities. In fact it's not really a sphere, but it is a wild planet, mottled with deadly volcanoes, rattled by killer earthquakes, drenched in disastrous deluges. But do you know which were the worst?

Some of Earth's valleys dip below sea level. Mountains soar into thin air. Can you name the lowest spot? The tallest peak? Do you know how far it is to the center of the planet or what's there?

Where are the planet's hottest, coldest, driest and windiest places?

The following list of Earth's extremes and other amazing facts is presented in Q&A format, so you can cover the answers to test your knowledge of the home planet.

1. What is the hottest place on Earth?

Count one wrong if you guessed Death Valley in California. True enough on many days. But El Azizia in Libya recorded a temperature of 136 degrees Fahrenheit (57.8 Celsius) on Sept. 13, 1922 -- the hottest ever measured. In Death Valley, it got up to 134 Fahrenheit on July 10, 1913.

2. And the coldest place around here?

Far and away, the coldest temperature ever measured on Earth was -129 Fahrenheit (-89 Celsius) at Vostok, Antarctica, on July 21, 1983.

3. What makes thunder?

If you thought, "Lightning!" then hats off to you. But I had a more illuminating answer in mind. The air around a lightning bolt is superheated to about five times the temperature of the Sun. This sudden heating causes the air to expand faster than the speed of sound, which compresses the air and forms a shock wave; we hear it as thunder.

4. Can rocks grow?

Yes, but observing the process is less interesting than watching paint dry. Rocks called iron-manganese crusts grow on mountains under the sea. The crusts precipitate material slowly from seawater, growing about 1 millimeter every million years. Your fingernails grow about the same amount every two weeks.

5. How much space dust falls to Earth each year?

Estimates vary, but the USGS says at least 1,000 million grams, or roughly 1,000 tons of material enters the atmosphere every year and makes its way to Earths surface. One group of scientists claims microbes rain down from space, too, and that extraterrestrial organisms are responsible for flu epidemics. There's been no proof of this, and I'm not holding my breath.

6. Where is the world’s highest waterfall?

The water of Angel Falls in Venezuela drops 3,212 feet (979 meters).

7. Is Earth a sphere?

Because the planet rotates and is more flexible than you might imagine, it bulges at the midsection, creating a sort of pumpkin shape. The bulge was lessening for centuries but now, suddenly, it is growing, a recent study showed. Accelerated melting of Earth's glaciers is taking the blame for the gain in equatorial girth.

8. What would a 100-pound person weigh on Mars?

The gravity on Mars is 38 percent of that found on Earth at sea level. So a 100-pound person on Earth would weigh 38 pounds on Mars. Based on NASA's present plans, it'll be decades before this assumption can be observationally proved, however.

9. What is the largest volcano?

The Mauna Loa volcano in Hawaii holds the title here on Earth. It rises more than 50,000 feet (9.5 miles or 15.2 kilometers) above its base, which sits under the surface of the sea. But that's all volcanic chump change. Olympus Mons on Mars rises 16 miles (26 kilometers) into the Martian sky. Its base would almost cover the entire state of Arizona.

10. What was the deadliest known earthquake?

The world’s deadliest recorded earthquake occurred in 1557 in central China. It struck a region where most people lived in caves carved from soft rock. The dwellings collapsed, killing an estimated 830,000 people. In 1976 another deadly temblor struck Tangshan, China. More than 250,000 people were killed.

11. What was the strongest earthquake in recent times?

A 1960 Chilean earthquake, which occurred off the coast, had a magnitude of 9.6 and broke a fault more than 1,000 miles (1,600 kilometers) long. An earthquake like that under a major city would challenge the best construction techniques.

12. What is the highest mountain?

Climbers who brave Mt. Everest in the Nepal-Tibet section of the Himalayas reach 29,035 feet (nearly 9 kilometers) above sea level. Its height was revised upward by 7 feet based on measurements made in 1999 using the satellite-based Global Positioning System.

13. Where is the lowest dry point on Earth?

The shore of the Dead Sea in the Middle East is about 1,300 feet (400 meters) below sea level. Not even a close second is Bad Water in Death Valley, California, at a mere 282 feet below sea level.

14. What is the longest river?

The Nile River in Africa is 4,160 miles (6,695 kilometers) long.

15. What's the driest place on Earth?

A place called Arica, in Chile, gets just 0.03 inches (0.76 millimeters) of rain per year. At that rate, it would take a century to fill a coffee cup.

16. What causes a landslide?

Intense rainfall over a short period of time can trigger shallow, fast-moving mud and debris flows. Slow, steady rainfall over a long period of time may trigger deeper, slow-moving landslides. Different materials behave differently, too. Every year as much as $2 billion in landslide damage occurs in the United States. In a record-breaking storm in the San Francisco area in January 1982, some 18,000 debris flows were triggered during a single night! Property damage was over $66 million, and 25 people died.

17. Do things inside Earth flow?

You bet. In fact, scientists found in 1999 that molten material in and around Earth's core moves in vortices, swirling pockets whose dynamics are similar to tornadoes and hurricanes. And as you'll learn later in this list, the planet's core moves in other strange ways, too.

18. What is the wettest place on Earth?

Lloro, Colombia averages 523.6 inches of rainfall a year, or more than 40 feet (13 meters). That's about 10 times more than fairly wet major cities in Europe or the United States.

19. Is air mostly oxygen?

Earth's atmosphere is actually about 80 percent nitrogen. Most of the rest is oxygen, with tiny amounts of other stuff thrown in.

20. What is the highest waterfall in the United States?

Yosemite Falls in California is 2,425 feet (739 meters).

21. What percentage of the world’s water is in the oceans?

About 97 percent. Oceans make up about two-thirds of Earth's surface, which means that when the next asteroid hits the planet, odds are good it will splash down.

22. Which two landmasses contain the vast majority of the Earth’s fresh water supply?

Nearly 70 percent of the Earth's fresh-water supply is locked up in the icecaps of Antarctica and Greenland. The remaining fresh-water supply exists in the atmosphere, streams, lakes, or groundwater and accounts for a mere 1 percent of the Earth's total.

23. Which of the Earth’s oceans is the largest?

The Pacific Ocean covers 64 million square miles (165 million square kilometers). It is more than two times the size of the Atlantic. It has an average depth of 2.4 miles (3.9 kilometers).

24. How much surface area does Earth contain?

There are 196,950,711 square miles (510,100,000 square kilometers).

25. What is the largest lake in the world?