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The nebular hypothesis is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System (as well as other planetary systems). It suggests the Solar System is formed from gas and dust orbiting the Sun which clumped up together to form the planets.
The nebular hypothesis says that the Solar System formed from the gravitational collapse of a fragment of a giant molecular cloud, [9] most likely at the edge of a Wolf-Rayet bubble. [10] The cloud was about 20 parsecs (65 light years) across, [ 9 ] while the fragments were roughly 1 parsec (three and a quarter light-years ) across. [ 11 ]
By the early 1980s, the nebular hypothesis in the form of SNDM had come back into favor, led by two major discoveries in astronomy. First, several young stars, such as Beta Pictoris, were found to be surrounded by discs of cool dust, much as was predicted by the nebular hypothesis.
This nebula was also observed by Johann Baptist Cysat in 1618. However, the first detailed study of the Orion Nebula was not performed until 1659 by Christiaan Huygens, who also believed he was the first person to discover this nebulosity. [11] In 1715, Edmond Halley published a list of six nebulae.
The natural history of Earth concerns the development of planet Earth from its formation to the present day. [ 1 ] [ 2 ] Nearly all branches of natural science have contributed to understanding of the main events of Earth's past, characterized by constant geological change and biological evolution .
As mentioned, the idea of the nebular hypothesis had been outlined by Immanuel Kant in 1755, [58] who had also suggested "meteoric aggregations" and tidal friction as causes affecting the formation of the Solar System. Laplace was probably aware of this, but, like many writers of his time, he generally did not reference the work of others. [8]
The chronology of the universe describes the history and future of the universe according to Big Bang cosmology. Research published in 2015 estimates the earliest stages of the universe's existence as taking place 13.8 billion years ago, with an uncertainty of around 21 million years at the 68% confidence level. [1]
1755 – Immanuel Kant advances Emanuel Swedenborg's nebular hypothesis on the origin of the Solar System. [17] 1765 – Leonhard Euler discovers the first three Lagrange points. [18] [19] 1767 – Leonhard Euler solves Euler's restricted three-body problem. [20] 1772 – Joseph-Louis Lagrange discovers the two remaining Lagrange points. [21]