Planet Explosion Low-poly 3D model

cgtrader

A celestial body is an astronomical entity revolving around a star or stellar remnant that is massive enough to be rounded by its own gravitational pull, yet not substantial enough to ignite thermonuclear fusion, and has purged its surrounding area of planetesimals. The term planet originates from ancient times, linking history, astrology, science, mythology, and religion. Five planets in our solar system are observable with the naked eye. These were viewed as divine or messengers of deities by many early civilizations. As scientific knowledge evolved, humanity's perception of the planets shifted, incorporating various celestial objects. In 2006, the International Astronomical Union officially adopted a resolution defining planets within the solar system. This definition is contentious because it excludes numerous planetary-mass objects based on their location or what they orbit. Eight of the pre-1950 discovered planetary bodies continue to be classified as planets under the current definition, whereas some celestial entities such as Ceres, Pallas, Juno, Vesta (all located in the solar asteroid belt), and Pluto (the first trans-Neptunian object discovered) were previously considered planets but are no longer regarded as such. Planets have a distinct meaning in astrology. The planets were believed by Ptolemy to revolve around Earth in deferent and epicycle motions. Although the concept that planets orbited the Sun had been proposed multiple times, it was not until the 17th century that this view gained support from evidence gathered through telescopic astronomical observations performed by Galileo Galilei. At roughly the same time, by carefully analyzing pre-telescopic observational data collected by Tycho Brahe, Johannes Kepler discovered that the planets' orbits were elliptical rather than circular. As observational tools advanced, astronomers noted that, similar to Earth, each planet rotated on an axis tilted relative to its orbital pole and some shared characteristics such as ice caps and seasons. Since the dawn of the Space Age, close observation by space probes has found that Earth and the other planets exhibit traits like volcanism, hurricanes, tectonics, and hydrology. Planets are primarily divided into two categories: large, low-density giant planets, and smaller rocky terrestrial planets. There are eight planets in our solar system. In ascending order of distance from the Sun, they consist of four terrestrial planets (Mercury, Venus, Earth, and Mars) followed by four gas giants (Jupiter, Saturn, Uranus, and Neptune). Six of the planets have one or more natural satellites orbiting them. In the 19th century, astronomers began to realize that certain bodies discovered recently (like Ceres, Pallas, Juno, and Vesta) differed significantly from traditional planets. These entities resided within a similar region of space between Mars and Jupiter (the asteroid belt) and possessed a smaller mass; as a result, they were reclassified as asteroids. Due to the absence of a formal definition, a planet was understood as any significant body orbiting the Sun. Given the notable size disparity between asteroids and planets and the conclusion that new discoveries had ceased after Neptune's discovery in 1846, there appeared to be no need for a formal definition. Following the detection during the latter half of the 20th century of numerous objects within our solar system and large celestial bodies orbiting other stars, disputes arose over what should define a planet. Notable disagreements existed over whether an object should be classified as a planet if it formed part of a distinct population such as a belt or was substantial enough to produce energy via the thermonuclear fusion of deuterium. An increasing number of astronomers argued for Pluto's reclassification from a planet because numerous similar objects approaching its size had been discovered within the same region of our solar system (the Kuiper belt) during the 1990s and early 2000s. Pluto was revealed to be merely one small body in a population consisting of thousands. Some bodies like Quaoar, Sedna, and Eris were proclaimed as the tenth planet by the media, but failed to garner scientific recognition. The announcement of Eris in 2005, an entity believed to possess a mass of about 27% more than Pluto, created the necessity and public desire for a formal definition of a planet. To address this concern, the International Astronomical Union established a task force to define a planet, and released its decision in August 2006. The number of planets decreased significantly to the eight distinctly larger bodies that had cleared their orbit (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune). A new category of dwarf planets was also created initially containing three objects: Ceres, Pluto, and Eris.