WebThe IAU published the original definition proposal on August 16, 2006. Its form followed loosely the second of three options proposed by the original committee. It stated that: A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is …

WebA dwarf planet is a small planetary-mass object that is in direct orbit of the Sun, smaller than any of the eight classical planets but still a world in its own right. The prototypical dwarf planet is Pluto.The interest of dwarf planets to planetary geologists is that they may be geologically active bodies, an expectation that was borne out in 2015 by the Dawn …

WebPlanet atau bintang siarah (dari bahasa Yunani Kuno αστήρ πλανήτης (astēr planētēs), berarti "bintang pengelana") adalah benda astronomi yang mengorbit sebuah bintang atau sisa bintang yang cukup besar untuk memiliki gravitasi sendiri, tidak terlalu besar untuk menciptakan fusi termonuklir, dan telah "membersihkan" daerah sekitar orbitnya yang …

WebA planet is a large, rounded astronomical body that is neither a star nor its remnant.The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a young protostar orbited by a protoplanetary disk.Planets grow in this disk by the gradual accumulation of material …

WebThe IAU's definition does not attach specific numbers or equations to this term, but all IAU-recognised planets have cleared their neighbourhoods to a much greater extent (by orders of magnitude) than any dwarf planet or candidate for dwarf planet. [citation needed]

WebA solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator, rather than north or south of the equator. On the day of the equinox, the Sun appears to rise "due east" and set "due west". This occurs twice each year, around 20 March and 23 September.. More precisely, an equinox is …

WebSaturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter.It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; however, with its larger volume, Saturn is over 95 times more massive. Saturn's interior is most likely composed of a core of …

WebEsta distinción se realizaba básandose en la apariencia visual al efectuarse su descubrimiento; los cometas debían mostrar una coma, y eran listados en sus propios catálogos.En contraste, los planetas menores aparecen como estrellas («asteroide», del griego αστεροειδές, asteroides = «como estrella», «con forma de estrella», del griego …

WebThe physical and orbital characteristics of the moons vary widely. The four Galileans are all over 3,100 kilometres (1,900 mi) in diameter; the largest Galilean, Ganymede, is the ninth largest object in the Solar System, after the Sun and seven of the planets, Ganymede being larger than Mercury.All other Jovian moons are less than 250 kilometres (160 mi) in …

WebIn classical antiquity, the seven classical planets or seven luminaries are the seven moving astronomical objects in the sky visible to the naked eye: the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn.The word planet comes from two related Greek words, πλάνης planēs (whence πλάνητες ἀστέρες planētes asteres "wandering stars, planets") and …