The Earth

More than two-thirds of Earth's land surface lies north of the equator.

If Earth was the size and weight of a table tennis ball, the Sun would measure 12 feet and weigh 3 tons. On this scale, the Earth would orbit the Sun at a distance of 1,325 feet.

The Earth rotates on its axis more slowly in March than in September.

The Earth is the most dense planet - five times denser than water, while Saturn is the least dense. It has a density 0.7 times that of water.

If the population of the Earth continued to increase at its present rate indefinitely, by 3530 A.D. the total mass of human flesh and blood would equal the mass of the Earth. By 6826 A.D. it would equal the mass of the known universe.

The Earth's average temperature, now 60 degrees, is about 11 degrees higher than it was 12,000 years ago, the peak of the last glacial maximum, and almost all that rise occurred before the impact of modern industrial man.

The temperature of Earth's interior increases by 1 degree every 60 feet down.

Without using precision instruments, Eratosthenes measured the radius of Earth in the third century B.C., and came within 1 percent of the value determined by today's technology.

Only about 1.6 percent of the water on Earth is fresh. Most of it is locked — unusable for living things — in snow and the ice at the poles and on the peaks of the highest mountains.

The bleakest places on Earth are the two poles: the South Pole has no sunshine for 182 days each year; the North Pole does slightly better--it has no sunlight for 176 days.

If the fresh water of the earth (only 1.6 percent of the water on the planet) was divided equally among all the people on earth, each one would get 40 million gallons.

Traveling at the speed of 186,000 miles per second, light take 6 hours to travel from Pluto to Earth.

More than two-thirds of Earth's land surface lies north of the equator.

The earth isn't round. If you measure its diameter at the equator you will get a bit more than 7, 926 miles. But from pole to pole it's 7, 882 miles. This planet is a triaxial ellipsoid, not a sphere. Source: THE JOY OF TRIVIA by Bernie Smith

On a clear day you can see . . . It's time to lay to rest another myth. Many people believe that there is one physical feature on Earth that is extensive enough to be seen from the moon: the Great Wall of China. It's not true. No man- or woman-made structure can be seen from there. The astronauts who went to the moon confirmed it.

Glaciers occupy 5.8 million square miles, or 10 percent of the world's land surface, as in an area as large as South America.

If you stand at the equator you will spin at about 1,000 miles per hour because of the Earth's rotation.

A bucket filled with earth would weigh about 5 times more than the same bucket filled with the substance of the Sun. However, the force of gravity is so much greater on the Sun that a man weighing 150 pounds on our planet would weigh 2 tons on the Sun.

The pressure at the center of the Earth is 27,000 tons per square inch. At the center of the giant planet Jupiter, the pressure is three times as great.

The Ptolemic Universe was based on the idea that the Earth was the center of the Universe. This incorrect conclusion was made by Ptolemy, a Greek astronomer, who eventually calculated the correct measurements of planetary movements.

If the Milky Way Galaxy was the size of the U.S.A., Earth would be far smaller than the smallest particle of dust, barely visible through the most powerful microscopes.

WHAT IS THE EARLIEST ERA OF GEOLOGIC TIME?
It is the Precambrian age, which began when the earth's crust formed, 4.6 billion years ago, and ended with the dawn of the Cambrian period, 570 million years ago. About seven- eighths of earth's history since the formation of the crust took place during the Precambrian age.

How long have people known the earth was round?
In the 6th century BC Greek mathematician Pythagoras said that earth is round - but few agreed with him. Greek astronomer Aristarchos said in the 3rd century BC that earth revolves around the sun - but the idea was not accepted. In the 2nd century BC Greek astronomer Erastosthenes accurately measured the distance around the earth at about 40,000 km (24,860 miles) - but nobody believed him. In the 2nd century AD Greek astronomer Ptolemy stated that earth was the center of the universe - most people believed him for the next 1,400 years.

Is the world really round?
The world is not round. It is an oblate spheroid, flattened at the poles, and bulging at the equator.

EARTH COALESCED IN 20 MILLION YEARS
A new analysis of minerals from meteorites suggest that it took about 20 million years for the Earth to coalesce from the materials of the early solar system, according to a report in this week's edition of the journal Science. Previous estimates had the time frame as closer to 50 million years. Because they are the oldest objects in the solar system that are available to study, meteorites are useful for estimating the time interval separating events during the formation of the solar system. The researchers examined meteorites containing radioactive forms of the elements niobium and zirconium, which are used to calibrate the passage of time. The new figure is a result of a careful separation of minerals in the samples. "We designed an extremely careful approach to separate the minerals and isolate the right ones," said Brigitte Zanda-Hewins, an associate professor at the mineralogy laboratory of the Muséum National d'Histoire Naturelle in Paris.

EVIDENCE THAT LIFE CAME FROM OUTER SPACE
Viable microorganisms have been discovered floating in Earth's upper atmosphere, evidence supporting the controversial theory life began by bacteria and other microbes arriving here from outer space. "We were able to conclude there were viable microorganisms present at different heights in the air," Chandra Wickramasinghe, of Cardiff University's Center for Astrobiology, told United Press International. Wickramasinghe's team reported last year they had discovered microorganisms high above Earth but were unable to grow them in the lab. Microbiologist Milton Wainwright of the University of Sheffield, England, was able to isolate and grow a fungus and two species of bacteria collected 25 miles above the planet surface. Wickramasinghe says the microbes are not new species and "they're extremely closely related to known Earth bacteria, but that's what the theory of panspermia predicts," because it holds that bacteria on Earth originated from space.

WHAT BELIEF WAS GALILEO FORCED TO RECANT BY THE INQUISITION IN 1633?
That earth revolved around a stationary sun. He was kept under house arrest for the last eight years of his life for debunking the traditional belief that the earth was the center of the universe.

EARTH MAY SURVIVE SUN'S EXPANSION, BUT LIFE WON'T
In about 7.5 billion years, the Sun will die. A new estimate extends the length of time the Earth will be habitable by 200 million years, according to a BBC online report. Still, the expansion of the Sun as it turns into an enormous red giant will eventually make the surface of the Earth too hot for life. "We had better get used to the idea that we shall need to build our own survival capsules - the planets are simply too far apart for planet-hopping to be a viable solution. Perhaps this is the ultimate justification for developing an International Space Station," said Robert Smith, reader in Astronomy at the University of Sussex. Solar evolution theory predicts that our star will eventually run out of fuel. When it enters its death throes, the Sun will swallow the closest planets, including Mercury and Venus. It had been assumed that Earth would meet the same fate, but the researchers led by Smith think that the orbit of the Earth will remain just outside the radius of the red giant, because its gravitation pull will weaken. The Earth will survive, but it will be charred, the researchers say. Still, others think life on Earth won't last another 7.5 billion years ago. James Kasting, a geoscientist at Pennsylvania State University, believes that in a billion years the Earth's water will boil away, leaving it arid and lifeless. "The story for life on Earth is long over by the time the Sun becomes a red giant."

When is the Earth closest to the Sun?
You might think that the Earth is closest to the Sun when the weather is warmest, but that's only true south of the equator. Earth's closest approach to the Sun (perihelion) happens around January 2, when it's winter in the north. Earth's orbit is so close to circular that the difference in distance between the closest and farthest points is very slight. The atmosphere and oceans hold so much of the Sun's warmth, that the effect of the distance changes is mostly invisible. On a longer time scale the effect may be much more important. The time of perihelion shifts by 25 minutes each year, making a full cycle around the yearly calendar every 21,000 years. This (and other long-term cycles) may be part of the reason for the ice ages.

WHAT IS THE DISTANCE OF THE MOON TO EARTH?
The average distance to the Moon from the Earth's surface is 232,841.69 miles. If there were a "lunar expressway" and you could drive your car at a constant speed of 65 mph it would take 3,582.18 hours or 4 months, 29 days, 6 hours and 10 minutes to reach the moon.

HOW MUCH DID NEWTON SAY THE EARTH WEIGHED?
Newton estimated correctly that the Earth had a mass of 6,600,000,000,000,000,000,000 tons and a density of about five-and-a-half times that of water. The fact wasn't demonstrated until one century after his estimate.

HOW THICK IS THE CRUST OF THE EARTH?
Sometimes likened to the shell that covers an egg, the layer of rock that covers the surface of the earth is, on average, 22 miles thick.

But what if the earth were a coconut?
If Earth were the size of an apple, the atmospheric layer would be no thicker than the skin of the apple.

What does the Earth's axis tilt do for us?
If the Earth's axis was not tilted, there would be 12-hour days everywhere, and no seasons. At the poles, the sun would always be on the horizon.

How long would it take to recycle all of Earth's water?
The total water content of the oceans on Earth would take one million years to be cycled through the atmosphere as part of the water cycle.

HOW MUCH DUST COMES FROM OUTER SPACE EACH DAY?
About 27 tons of dust rains down on the earth each day from space, making a total of almost 10,000 tons each year.

What part of Earth's atmosphere is made of plasma?
The outer atmosphere of Earth contains several distinct layers. The highest layer, called the plasmasphere, is composed of charged particles ( plasma) rather than normal gas. The plasmasphere is a donut-shaped region several times the size of Earth that contains cooler and much denser plasma than the region outsi de of it. The plasma is produced by interactions between the sun's radiation and the upper atmosphere. It is kept in place by Earth's magnet ic field. Within the plasmasphere, there are thousands of particles, or more, in a cubic centimeter of space (about the volume of a thimble). Outsid e is interplanetary space, with a density of less than one particle in the same volume.

Air's Weight
Even though it doesn't feel very heavy, air actually weighs a lot. A column of air with a one square inch base reaching from sea level to the top of the atmosphere weighs about 14.7 pounds (6.6 kg), and a cubic yard (or cubic meter) of air at sea level weighs about 2 pounds (about 1 kg). This means that walking along the beach, you have over 1000 pounds (450 kg) of air above your head and shoulders, and the air in the average high school gym weighs over three tons!

Is the greenhouse effect bad?
No, merely an abundance of it. Without any greenhouse effect, Earth would be cold and lifeless with an average temperature of 0.4 degrees Fahrenheit.

What is the deepest spot in the oceans?
The greatest ocean descent was made in 1960 in the U.S. Navy bathyscape Trieste, manned by Dr. Jacques Piccard of Switzerland and Lt. Donald Walsh of the United States. In their vessel, these two men reached a depth of 35,979 feet at a place in the Pacific Ocean called the Mariana Trench, the deepest spot in the oceans and the lowest point of Earth's surface. Compare that depth with the highest mountain peaks in the world. Do you think the land rises higher above sea level than it descends below sea level? Mount Everest in Nepal, at 29,002 feet, is the highest point in the world. The highest peak in North America is Mt. McKinley in Alaska at 20,320 feet.

How far has mankind descended into the ocean's depths?
On January 23, 1960, Swiss adventurer Jacques Piccard and U.S. Navy Lt. Donald Walsh climbed into the bathyscaphe Trieste and began a dive that would go deeper into the ocean's waters than anyone has traveled before or since. During a five-hour descent into the Challenger Deep off the Pacific's Marianas Islands, water pressure on the vessel, which had been jointly designed by Piccard and his father (explorer Auguste Piccard), rose to more than 16,000 pounds per square inch. Ultimately, they plunged to nearly 36,000 feet, some 7,000 feet deeper than Mt. Everest's height above sea level. To their surprise, they observed fish swimming about, which disappointed some scientists who had hoped to use the ocean's depths as radioactive waste disposal sites-- had they been found to be stagnant and devoid of life.

Are you heavier at the North or South Pole than anywhere else on Earth?
Absolutely - Gravity has a stronger pull at the Earth's poles than it does at the equator. As a result, a person who weighs 150 lbs at the equator, would weigh almost a pound heavier if he/she stood at the North Pole. This is because the earth is not perfectly round - It flattens out somewhat at the poles. Therefore, a person standing at the poles is actually thirteen miles closer to the center of the earth than he/she is when standing at the equator. The pull of gravity increases as you move closer to the center of a gravitational mass, making objects heavier. In addition, the centrifugal spin effect at the equator slightly counteracts the pull of gravity. All of this translates into a difference of almost a pound between what a person would weigh at the equator versus the poles.

How much space do glaciers take up?
Glaciers occupy 5.8 million square miles, or 10 percent of the world's land surface, as in an area as large as South America.

How thick is the ice in Antarctica?
About 98% of Antarctica is covered with ice, and the average thickness of the Antarctic ice sheet is 7,200 feet (2,200 meters). The thickest ice, found in Wilkes Land, is 15,700 feet (4785 m) thick. This is about ten times the height of the Petronas Towers in Malaysia, the world's tallest office building! Antarctica holds about 70% of all the freshwater in the world in its ice. If all the ice were to melt, sea level would rise 230 feet (70 meters). If this happened, the reduced pressure on the continent of Antarctica would cause it to rise about 3200 feet (1000 m).

How many deaths have been attributed to being hit by a meteor?
A dog was killed by a meteor at Nakhla, Egypt, in 1911. The unlucky canine is the only creature known to have been killed by a meteor.

EVIDENCE OF OLDEST METEOR IMPACT
A team of geologists has found evidence of an ancient meteorite that slammed into Earth 3.47 billion years ago. Geological evidence collected on two continents suggests the meteorite was approximately 12 miles (20 kilometers) wide -- roughly twice as big as the one that contributed to the demise of the dinosaurs some 65 million years ago. Researchers collected samples from two South African and Australian rock formations. Although thousands of miles apart, both sites contain 3.5-billion-year-old layers of rock embedded with "spherules" - tiny spherical particles that are a frequent byproduct of meteorite collisions. The meteorite that led to the dinosaur extinction produced spherule deposits around the world less than two centimeters deep. But the spherule beds in South Africa and Australia are much bigger -- some 20 to 30 centimeters thick. A chemical analysis of the rocks also has revealed high concentrations of rare metals, such as iridium -- rare in terrestrial rocks but common in meteorites.