Earth is a terrestrial planet (a rocky world with a solid surface). The ocean covers about 70% of the surface. Earth's layers are the crust, mantle, and core. The atmosphere protects the planet from incoming asteroids.
Earth's atmosphere comprises nitrogen, oxygen, and small trace amounts of argon, carbon dioxide, and water vapor. Carbon dioxide and methane trap heat in the atmosphere, contributing to climate change. Water vapor plays a role in weather patterns. Air pressure and temperature decrease as altitude increases.
Earth has both landforms and bodies of water. The landforms include mountains, plains, plateaus, canyons, volcanoes, and valleys, while the bodies of water include rivers, lakes, glaciers, and oceans. There are also ocean trenches and mid-ocean ridges.
Earth is a prime location for life due to its temperature range, abundant liquid water, and magnetic field that protects the planet from harmful solar radiation.
The Greeks and Romans developed cartography and astronomical observations.
European explorers and cartographers charted new lands, sea routes, and resources.
The beginning of developments in geology and natural history, with scientists and explorers studying Earth's structure, rocks, and life.
Sputnik (one of the first artificial satellites) was launched, and the development of remote sensing technologies marked the beginning of space-based Earth observation.
Human-crewed missions allowed for direct Earth observation and scientific research from space.
A network of satellites constantly monitors Earth's systems, which provides data for research and environmental monitoring.