Светлана11 дней назад
Earth is the third planet from the Sun and the only known planet to support life. It formed approximately 4.6 billion years ago and is part of the inner, rocky planets of the Solar System. Key characteristics: Orbit and rotation: Earth completes one orbit around the Sun in 365.25 days (a year) and rotates on its axis every 24 hours (a day). Its axial tilt causes the seasons. Structure: The planet has three main layers — the core, the mantle and the crust. Surface: About 71 % of the surface is water (mostly oceans), and 29 % is landmass, organised into seven continents. Atmosphere: It consists mainly of nitrogen (78 %) and oxygen (21 %), with small amounts of other gases. This mixture protects life and regulates climate. Moon: Earth has one natural satellite, the Moon, which influences tides and stabilises the planet’s rotation. Uniqueness: Earth’s distance from the Sun, presence of liquid water, and protective atmosphere make it uniquely suitable for a wide variety of life forms.