The Earth is the third planet from the Sun, and the only planet in the solar system not named after a mythical god. The Earth is also the only place we know of that supports life. It is 4.5 billion years old, with the oldest fossils of living organisms yet discovered dating back 3.9 billion years.
Here are some more interesting facts about the planet Earth:
Core: Earth is the densest body in our solar system, and its core is composed mostly of iron and nickel. This creates a magnetic field around the Earth, called the magnetosphere, without which the Earth would be exposed to significant amounts of radiation from the solar wind.
Surface: Earth’s surface is covered 71% with liquid water, a substance that is essential for the presence of life. It is also the only planet in the solar system to have water in its three states of matter; as a solid, liquid, and gas.
Atmosphere: The Earth’s atmosphere is 77% nitrogen, 21% oxygen, with traces of argon, carbon dioxide, and water. The oxygen in the Earth’s atmosphere is produced and maintained by biological processes, while the trace amounts of carbon dioxide are essential for stabilizing the Earth’s temperature.
Dimensions: Earth has a diameter of 7,926 miles (12,756 km) and is almost a sphere, but the Earth’s rotation causes the equator to bulge out 43 km more than its pole-to-pole measurement.
Moons: The planet has only one natural satellite, called the Moon. However, there are also two co-orbital satellites orbiting the Earth named 3753 Cruithne (5km wide) and 2002 AA29 (60 meters wide).
Orbit: The Earth speeds around the Sun at roughly 18.5 miles per second, and travels around the center of our Milky Way galaxy at 150 miles per second.