NO NEED TO TRAVEL in a cramped spaceship to find the fascinating planet in the solar system. You're standing on it! Our planet is one-of-a-kind- a world that, in many ways, is more mysterious than our own moon. Get to know Earth from its fiery birth to its present-day, from its frozen poles to its molten core, and you'll see that there really is no place like home.

WHY IS EARTH SPECIAL?

Earth is a special spot in the solar system for so many reasons. 

Its sprawling continents, its blue seas, its nearly limitless variety of ice-cream flavors. But one earthly thing stands out above the rest: its Earthlings. Ours is the only planet currently known to harbor life. In fact, Earth's unique combination of air, water, and land nurtures the life of every sort, from microscopic amoebas to submarine-size blue whales.

What conditions on Earth make it so favorable for life?

Earth's atmosphere not only provides the right mix of breathable air for animals and plants, but it-  combined with the oxygen-rich ozone layer and the planet's electromagnetic field - also acts as a force field against solar radiation and deadly space debris. The solar system's other planets are typically too hot or too cold to support liquid water, but Earth is just right. The ocean covers nearly 70 percent of the planet's surface and is a source of the water vapor responsible for our weather.

WHY IS THE EARTH ROUND?

Actually, it's not perfectly round. It's an '' oblate spheroid '' sphere slightly wider at the Equator than at the Poles. Gravity squashed Earth and the solar system's other planets into spherical shapes back when they formed from clouds of dust and gas. Earth's rotation is what causes its slight bulge around the middle.

WHAT MAKES THE WORLD GO AROUND?

Earth's rotation is a side effect of the formation of our solar system, which started as a massive cloud of gas and dust. Roughly 4.6 billion years ago. The cloud began to rotate as it. Scrunched together under its own gravity. The material at the center eventually became the sun, while whirlpools of dust and gas farther out spun faster and faster until they formed into planets. With nothing to stop its spinning motion, Earth retained the rotation from its early days.

OUR PLANET'S rotation is actually decreasing because of the moon's gravitation pull. Worry not - it will take millions of years for us to notice that our days and nights are just the teeniest bit longer. 

HOW FAST DOES THE EARTH SPIN?

Along the equator - the imaginary line halfway between the North and South Poles- Earth rotates at 1,037 mph (1,670 kph), a speed rivaling that of a fighter jet at full cruise.

WHY DOES THE EARTH SPIN FASTEST AT THE EQUATOR?

Still, confused? That's where the Earth is widest along its axis, so any point along the Equator has a greater distance to travel during each daily rotation than any point closer to the Poles. Think of a merry-go-round. The horses on the outside have a greater distance to travel around the carousel and thus move faster than the inside.

WHY DON'T WE FEEL THE EARTH SPINNING?

There are two reasons: gravity and the fact that we're travelling at the same speed as the ground beneath our feet. Just as airplane passengers don't sense the forward motion of the aircraft they're riding in (unless it suddenly speeds up or slows down), we don't notice the rate of Earth's rotation. We're traveling along Earth's surface as it spins and holds to the surface by its gravity - along with the atmosphere around us, the bicycles and cars on the road, and the birds in the sky.

WHAT WOULD HAPPEN IF THE EARTH SUDDENLY STOPPED SPINNING?

Buildings would topple. Mountains would crumble. Seas would slosh into our bedroom. If Earth suddenly put on the brakes, everything and everyone on it would suddenly hurl in the direction of the planet's former spin. (People who live closer to the Equator - where Earth's spin is the fastest would have the roughest ride.) Gravity would keep us from flying into space, but Earth would become a different place - even for those who live far from the Equator. For starters, the worldwide system of time zones (created to adjust the local time based on the Earth's rotation) would change drastically. A day would last a year (it would now take 365 days for the sun to return to its original place in the sky). Crops would wither. We'd all need to slather on heavy-duty sunscreen to survive six months of sunlight before bundling up for six months of night. The good news is that this nightmare scenario is a virtual impossibility.

SPACE AGENCIES, like NASA, build their launch facilities closer to the Equator to take advantage of Earth's faster rotation, which gives rockets and shuttles a speed boost into orbit.

 EARTH'S CHEMICAL COMPOSITION

Oxygen is the most bountiful component in rocks in Earth's covering, making around 47% out of the heaviness of all stone. The second most bountiful component is silicon, at 27%, trailed by aluminum, at 8%; iron, at 5%; calcium, at 4%; and sodium, potassium, and magnesium, at around 2% each.

Earth's center generally comprises iron and nickel and conceivably more modest measures of lighter components, like sulfur and oxygen. The mantle is made of iron and magnesium-rich silicate rocks. (The mix of silicon and oxygen is silica, and minerals containing silica are known as silicate minerals.)

EARTH'S INTERNAL STRUCTURE

Earth's center is around 4,400 miles (7,100 km) wide, marginally bigger than a large portion of the Earth's distance across and about similar size as Mars. The center's peripheral 1,400 miles (2,250 km) are fluid, while the internal center is strong. That strong center is around four-fifths as large as Earth's moon, at exactly 1,600 miles (2,600 km) in measurement. The center is answerable for the planet's attractive field, which assists with avoiding destructive charged particles shot from the sun.

Over the center is Earth's mantle, which is around 1,800 miles (2,900 km) thick. The mantle isn't substantial yet can stream gradually. Earth's outside glides on the mantle much as a piece of wood coasts on water. The sluggish movement of rock in the mantle rearranges mainlands around and causes seismic tremors, volcanoes, and the development of mountain ranges.

Over the mantle, Earth has two sorts of cover. The dry place known for the mainlands comprises the stone and other light silicate minerals, while the seafloor comprises most of a dim, thick volcanic stone called basalt. Mainland covering midpoints around 25 miles (40 km) thick, even though it tends to be more slender or thicker in certain spaces. The maritime covering is normally just around 5 miles (8 km) thick. Water fills in low spaces of the basalt covering to frame the world's seas.

Earth gets hotter toward its center. At the lower part of the mainland covering, temperatures reach around 1,800 degrees Fahrenheit (1,000 degrees Celsius), expanding around 3 degrees F for each mile (1 degree C for every km) underneath the outside. Geologists think the temperature of Earth's external center is around 6,700 to 7,800 degrees F (3,700 to 4,300 degrees C) and that the internal center might arrive at 12,600 degrees F (7,000 degrees C) — more blazing than the outside of the sun.

PERSON OF INTEREST

WHO?

Nicolaus Copernicus

WHAT IS HE FAMOUS FOR?

Putting the Earth in its place

When?

A.D.1543

WHERE?

Poland

WHY IS HE IMPORTANT?

Today it's common knowledge that the sun- not Earth-lies in the solar system. But before Polish mathematician Nicolaus Copernicus was born, people thought our planet sat at the center of the entire universe, not just the local neighborhood. Copernicus noticed that some planets appeared to change directions when moving across the sky. Earlier astronomers developed elaborate explanations for this mysterious phenomenon, known

as retrograde motion, but Copernicus saw it as proof that Earth orbited the sun just like the other planets did. It was a dangerous theory that went against the teachings of the Catholic Church, so Copernicus didn't publish his big idea until his final days.