Origin of Earth

It is believed that the Earth, along with the other planets, appeared 4.5 billion years ago as a solidified cloud of dust and gas left behind by the creation of the Sun. For perhaps 500 million years, the interior of the Earth remained solid and relatively cold, perhaps 2000F. The main ingredients, according to the best available evidence, were iron and silicates, along with small amounts of other elements, some of them radioactive. Over millions of years, the energy released by radioactive decay? Mainly uranium, thorium and potassium? It gradually warmed the Earth, dissolving some of its constituents. The iron dissolves before the silicates and, being heavier, sinks towards the center. This raised the silicates that it found there. After many years, the iron reached the center, almost 4,000 miles deep, and began to accumulate. At that time, there were no eyes around to see the turmoil that must have taken place on the Earth's surface: gigantic uplifts and bubbles on the surface, erupting volcanoes and lava flows covering all that was in sight. Eventually, the iron in the center accumulated as a core. Around it, a thin but fairly stable crust of solid rock formed as the Earth cooled. Crustal depressions were natural reservoirs in which water, rising from the interior of the planet through volcanoes and fissures, came together to form oceans. Slowly, the Earth acquired its present appearance.

Formation of Planets

The following are appeared because the degrees withinside the planets’ development:

Ø  The stars are localised fueloline lumps internal a nebula.

Ø  A center to the fueloline cloud in addition to a spinning disc of dirt and fueloline are created due to the gravitational pressure in the lumps.

Ø  After this, the cloud of the fueloline condenses and the problem over the center is modified into tiny rounded items.

Ø  These small spherical items grow to be what are referred to as planetesimals through a concord process.

Ø  The smaller items begin forming large our bodies through colliding with each other and that they stick collectively due to gravitational pressure.

Ø  In the ultimate stage, those huge quantities of small planetesimals combination to grow to be a smaller quantity of huge our bodies referred to as planets.