Earth Facts

Earth Planet Profile

Population:	7.53 billion (2017) Trending, World Bank
View on Maps:	google.com/maps/space/earth
Distance from Sun:	92.96 million mi
Radius:	3,959 mi
Polar Diameter:	12,714 km
Orbital Period:	265.24 days
Mass:	5.972 × 10^24 kg
Number of Moons:	1
Age:	4.543 billion years

Earth is the third planet from the Sun in our Solar System. While it is the largest of the terrestrial planets, it is only the fifth largest planet in mass and size and yet the densest of all of the planets.

Earth has the distinction of being the only planet in our Solar System that is not named after a god, goddess, or any other mythological being.

The name “Earth” is derived from the Old English word “ertha” as well as the Anglo-Saxon word “erda”, which means soil or ground. Earth is the only known planet to support life and was formed around 4.54 billion years ago.

Center of the Universe

In ancient times, astronomers believed that the Earth was the center of the universe and all planets as well as the Sun revolved around Earth.

For over 2,000 years they thought that they Earth was static or non-moving, and it wasn’t until Copernicus published his Sun-centered Solar System model in 1543 that scientists found that the Sun was the center of the Solar System.

Life on Earth is believed to be due to the perfect distance from the Sun, combined with the gravitational effects of the moon. Scientists like to call the position of the Earth as “not too hot, not too cold,” with the name of “the Goldilocks distance.”

Earth has one moon and the gravity between the moon and the Earth cause the tides on Earth. This effect is known as being “tidally locked” so that its orbit time and rotation period is the same. This is what gives us the same side constantly facing the Earth.

Earths Atmosphere

The atmosphere of the Earth is made up of 78% nitrogen, 21% oxygen, and trace amounts of other gases including carbon dioxide and argon. The huge amount of oxygen that is in the atmosphere is generated from the plant life on the Earth as it consumes carbon dioxide during the photosynthesis process.

The Ozone layer around the Earth is a special kind of oxygen that absorbs many of the Sun’s harmful UV rays, protecting the planet and life from excessive solar radiation.

Life on Earth

Earth has an abundance of life that live on both land and in the sea and waterways. Scientists had once thought that only these life forms should be considered true “life” as they needed fluid water, sunlight for energy, and some form of food.

They have since discovered lifeforms on earth that exist outside of the previous definitions, living in conditions that were thought to be uninhabitable. These life forms are now called “extremophiles” and have redefined our idea of “life.”

Earth’s magnetic field

Earth has an incredible powerful magnetic field that protects the planet from the solar wind effects. It is believed that the magnetic field is due to the nickel-iron core of the planet as well as the rapid rotation of the Earth. However, Earth’s rotation is slowing down at around 17 milliseconds per every 100 years.

This effect will eventually cause a lengthening of days, but it will take almost 140 million years to increase our 24 hour day to 25 hours.

70% of the surface of the Earth is covered by water, with the land areas consisting of continents, islands, and other land masses. Many of the land areas also have sources of fresh water. Scientists believe that the water on Earth was originally tapped inside the planet and brought to the surface slowly over time by volcanic activity.

Facts about Earth

• Earth has very few craters that are visible due to constant overgrowth, erosion, and geological changes that reshape and reform the surface.
• It’s believed that Earth’s first life was developed in the oceans and seas through a process called biopoiesis or abiogenesis. This process is described as a method for life to grow from non-living matter such as simple organic compounds.
• The highest point on the surface of the Earth is Mount Everest that is 8.8 km high.
• The lowest point on the Earth is an area called “Challenger Deep” and is 10.9 km below sea level.
• Of all of the eight planets in the Solar System, the Earth has the most circular orbit. The axis of rotation is tilted in such a way that it creates the seasons of the year that we have.
• Scientists believe that while some of Earth’s water was beneath the surface, other sources of water was delivered by comets.
• One Earth year is 365 days plus a little. This is why we add one additional day every four years, which we call a “Leap Year.”

Astronomy for Kids