Planet Earth Facts
The striking image of our blue planet set against the darkness of space
- Earth is the third planet from the sun, orbiting at a distance of 93 million miles (150 million km).
- It is the fifth biggest planet in the solar system with a diameter of 8,000 miles (13,000 km).
- Earth is around 4.5 billion years old.
- The Earth spins on its own axis every 23 hours 56 minutes and takes 365 days 6 hours to orbit the sun.
- The inner core of the Earth creates a magnetic field around the planet which protects it from solar winds, the liquid metal core is believed to be hotter than the surface of the sun.
- Life first appeared on the planet 3.5 billion years ago in the form of single celled organisms.
- Modern humans have only existed on the planet for around 200,000 years.
- The Earth is less well mapped than the Moon, Venus or Mars because the majority of its surface is covered by water.
- The first picture of Earth taken from space occurred in October 1946.
- There are more than 3,000 spacecraft currently orbiting the Earth.
Niagara Falls on the Canadian-American border
Earth's Surface70% of Earth's surface is covered by water. The rest is made up of land covered by forests, deserts, mountain ranges, grassy plains and two polar ice caps. There are also a small amount of active volcanoes.
Earth's AtmosphereNitrogen makes up 78 percent of the atmosphere, while oxygen makes up 21 percent. The remaining 1 percent consists of argon and small amounts of other gases.
Earth's TemperatureThe average temperature on Earth is 13C (55F) to 17C (63F). The coldest temperatures can be found at the poles, around -34C (-30F), the hottest at the equator, around 32C (90F).
Life on EarthLife has existed on Earth for at least 3.5 of its 4.5 billion year history and is found almost everywhere on the planet. From the air to the oceans, from mountain tops to ocean basins, from polar glaciers to desert sands, from the surface to many miles below. The variety of life on Earth is extraordinary, there are millions of different types of animal and plant life, each perfectly adapted to their natural environment through the process of evolution. The key to life on Earth is water, it is thought that without it life is unable to exist, seven tenths of our planet's surface is covered in oceans, seas, lakes and rivers making Earth a veritable oasis in our little corner of the Milky Way galaxy.
Moons & Origin of NameThe Earth has one moon.
The name "Earth" is derived from the Anglo-Saxon word erda, meaning ground or soil.
Interior of Earth
The Earth is made up of layers
This is the rocky outer layer of the Earth, what we walk on every day and what makes up the ocean floor. The crust isn’t one solid object, it is broken up into plates which move and collide with each other, causing mountain ranges to form or earthquakes to occur. The land mass of the Earth is constantly shifting but at a very slow pace, creating new continents over millions of years. Mantle
Around 5 miles (8 kilometers) below the ocean floor we find the next layer, called the mantle. This is also made of solid rock, rock so hot that it would flow on Earth’s surface but deep underground pressure doesn’t allow it to melt, instead it moves extremely slowly in currents. Occasionally it will find its way to the surface and explode violently from volcanoes as magma. The mantle is the thickest layer of Earth’s structure, extending for around 1,850 miles (3,000 km). Outer Core
Below the mantle we find the outer core, the only layer of the Earth that can be described as liquid, here the composition changes form rock to metal, in the case of the outer layer in the form of extremely hot liquid iron. It is thought that Earth’s magnetic field is created by the outer core which protects us from radiation emanating from the sun. The outer core descends a further 1,400 miles (2,250 km). Inner Core
Here we find the last layer of our onion like planet and the very center of Earth, the inner core is mostly solid iron and nickel with temperatures similar to that found on the surface of the sun. The inner core has a diameter of around 800 miles (1,290 km).
The Evolution of Earth
How early Earth would have looked like
A shuttle astronaut on a space walk against the backdrop of planet Earth
Planet Earth StatisticsDiameter: 7,926 miles (12,756 km)
Average Distance from Sun: 93 million miles (150 million km)
Orbital Period: 365.24 days
Rotation Period: 23.934 hours
Maximum Surface Temperatures: 58C (136F)
Minimum Surface Temperatures: -88C (-126F)
Gravity: 9.766 m/s2
Density: 5.515 g/cm3
Mass: 5.9737 x 1024 kg
Volume: 1.0832 x 1012 km3
Atmosphere: 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide.