The Earth

The Earth is the third planet from the Sun, and the densest and fifth-largest of the eight satellites in the Solar System. It is furthermore the largest of the Solar System's four terrestrial planets. It is occasionally referred to as the world or the Blue Planet.

soil formed approximately 4.54 billion years ago, and life emerged on its surface inside its first billion years. Earth's biosphere then considerably altered the atmospheric and other rudimentary physical situation, which enabled the expansion of organisms as well as the formation of the ozone level, which simultaneously with Earth's magnetic area impeded harmful solar radiation, and allowed previously ocean-confined life to move securely to land. The personal properties of the soil, as well as its geological history and orbit, have permitted life to persevere. Estimates on how much longer the planet will be adept to continue to support life variety from 500 million years (myr), to as long as 2.3 billion years (byr).

Earth's lithosphere is divided into some rigid segments, or tectonic plates, that migrate across the exterior over periods of many millions of years. About 71% of the exterior is covered by saline water oceans, with the remainder comprising of countries and isles which together have numerous lagoons and other sources of water that contribute to the hydrosphere. Earth's poles are mostly enclosed with ice that is the solid ice of the Antarctic ice sheet and the sea ice that is the polar ice packs. The planet's central remains hardworking, with a solid iron inner centre, a fluid outside centre that generates the magnetic field, and a thick level of somewhat solid mantle.

Earth gravitationally interacts with other objects in space, especially the Sun and the Moon. During one orbit round the Sun, the soil rotates about its own axis 366.26 times, creating 365.26 solar days, or one sidereal year.[note 7] The Earth's axis of rotation is tilted 23.4° away from the perpendicular of its orbital plane, making cyclic variations on the planet's surface with a time span of one tropical year (365.24 solar days) The Moon is Earth's only natural satellite. It started orbiting the Earth about 4.53 billion years ago (bya). The Moon's gravitational interaction with Earth stimulates ocean surges, stabilizes the axial tilt, and gradually slows down the planet's rotation.

The planet is dwelling to millions of species of life, encompassing humans. Both the inorganic resources of the planet and the products of the biosphere contribute assets that are used to support a international human population. These inhabitants are grouped into about 200 independent sovereign states, which interact through diplomacy, travel, trade, and military activity. Human cultures have evolved numerous outlooks of the planet, including its personification as a planetary deity, its shape as flat, its place as the centre of the cosmos, and in the up to date Gaia standard, as a lone, self-regulating organism in its own right.