Mei 27, 2013
A nebula (from Latin: "cloud"; pl. nebulae or nebulæ, with ligature or nebulas) is an interstellar cloud of dust, hydrogen, helium and other ionized gases. Originally, nebula was a name for any diffuse astronomical object, including galaxies beyond the Milky Way. The Andromeda Galaxy, for instance, was referred to as the Andromeda Nebula (and spiral galaxies in general as "spiral nebulae") before the true nature of galaxies was confirmed in the early 20th century by Vesto Slipher, Edwin Hubble, et. al. Nebulae are often star-forming regions, such as in the Eagle Nebula. This nebula is depicted in one of NASA's most famous images, the "Pillars of Creation". In these regions the formations of gas, dust, and other materials "clump" together to form larger masses, which attract further matter, and eventually will become massive enough to form stars. The remaining materials are then believed to form planets, and other planetary system objects.
Nebula hypothesis was first put forward by Emanuel Swedenborg (1688-1772) in 1734 and completed by Immanuel Kant (1724-1804) in 1775. Similar hypothesis developed by Pierre Marquis de Laplace independently in 1796. This hypothesis, which is better known as the Kant-Laplace hypothesis Nebula, mentions that in the early stages, Solar System still be smog monster.
Fog is formed from dust, ice, and gas called nebulae, and that most of the elements of hydrogen gas. Possessed gravity causes it to shrink and rotate fog in a certain direction, temperature heat haze, and eventually became a giant star (sun). Giant sun continued to slide and rotate faster, and gas rings and ice thrown around the Sun. Due to gravity, these gases condense in line with the drop in temperature and form planets and outer planets. Laplace argued that the nearly circular-shaped orbit of the planets is a consequence of their formation.
