Preface

Earth and Mars

From mostly Wikipedia

Added something by author

Earth or we call it ɝːθ (what is that?) is the third planet from sun and is the largest of terestial planet in the solar sistem, the only living planet, yet till now. There are “cool” name beside earth, “gaia” and “terra”

Earts is the home to millions of species including humans. Untill now, earth is the only place in the universe where living being is known to exist. From now, it’s predict and had been search that earth had live for4.54 billions years, and life began appeared on its surface within a billion years. Since then, Earth’s biosphere has significantly altered the atmosphere and other abiotic conditions on the planet, enabling the proliferation of aerobic organism as well as the formation of the ozone layer which, together with Earth’s magnetic field, blocks harmful radiation from sun, minimalize from meteor permitting life on land.

Earth’s outer surface is divided into several rigid segments, or tectonic plates, that gradually migrate across the surface over periods of many million years. About 71% of the surface is covered with oceans that contain salt, the remainder consisting of continents and islands; liquid water, necessary for all known life, is not known to exist on any other planet’s surface (But lately, In Mars has found water). Earth’s interior remains active, with a thick layer of relatively solid mantle, a liquid outer core that generates a magnetic field, and a solid iron inner core.

Earth interacts with other objects in outer space, including the Sun and the Moon. At present, Earth orbits the Sun once for every roughly 366.26 times it rotates about its axis. This length of time is a sidereal year, which is equal to 365.26. The Earth’s axis of rotation is tilted 23.4° away from the perpendicular to its orbital plane, producing seasonal variations on the planet’s surface with a period of onetropical year (365.24 solar days). Moon is the only Earth’s natural satellite, which began orbiting it about 4.53 billion years ago, provides ocean tides, stabilizes the axial tilt and gradually slows the planet’s rotation. A cometary bombardment during the early history of the planet played a role in the formation of the oceans. Later, asteroid impacts caused significant changes to the surface environment. Long term periodic changes in the Earth’s orbit, caused by the gravitational influence of other planets, are believed to have given rise to the ice ages that have intermittently covered significant portions of Earth’s surface in glacial sheets.

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