Earth is the third planet from the sun and is the only known planet in the universe to support life. It is a terrestrial planet with a solid and rocky surface, and its atmosphere is composed of nitrogen, oxygen, carbon dioxide, and other trace gases. Earth has a diameter of approximately 12,742 kilometers (7,918 miles) and a mass of approximately 5.97 x 10^24 kilograms.

Due to the large amount of water present on its surface, Earth is frequently referred to as the "Blue Planet". Oceans span around 71% of Earth's surface and hold 97% of the planet's water. Freshwater, which is found in rivers, lakes, and groundwater, makes up the remaining 3% of the planet's water.
With an estimated 8.7 million species existing at this time, Earth is home to a huge variety of plant and animal life. The estimated 300,000-year-old evolution of humans on Earth has had a profound effect on the ecosystems and natural resources of the planet.

Earth has a dynamic geology that contributes to its rich and complex biosphere by triggering earthquakes, volcanic eruptions, and the development of mountain ranges. Earth's atmosphere also protects the planet from harmful solar radiation and provides the conditions necessary for weather patterns and climate.
Overall, Earth is a singular and intriguing world, and understanding its many intricate processes is crucial for comprehending both the present and future of our planet as well as the possibility of life elsewhere in the cosmos.