Theia is a hypothesized ancient planet in the early Solar System that, according to the giant-impact hypothesis, collided with the early Earth around 4.5 billion years ago, with some of the resulting ejected debris gathering to form the Moon.. In addition to explaining Earth's large satellite, the Theia hypothesis can also explain why Earth's core is larger than expected for a …

The giant-impact hypothesis, sometimes called the Big Splash, or the Theia Impact, suggests that the Moon formed from the ejecta of a collision between the proto-Earth and a Mars-sized planet, approximately 4.5 billion years ago, in the Hadean eon (about 20 to 100 million years after the Solar System coalesced). The colliding body is sometimes called Theia, from the name of …

Planet 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 dipenuhi planetesimal.

Phaeton (alternatively Phaethon / ˈ f eɪ. ə θ ən / or Phaëton / ˈ f eɪ. ə t ən /; from Ancient Greek: Φαέθων, romanized: Phaéthōn, pronounced [pʰa.é.tʰɔːn]) was the hypothetical planet hypothesized by the Titius–Bode law to have existed between the orbits of Mars and Jupiter, the destruction of which supposedly led to the formation of the asteroid belt (including the ...

The 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 in orbit around a star, and …

A giant planet is a massive planet and has a thick atmosphere of hydrogen and helium.They may have a dense molten core of rocky elements, or the core may have completely dissolved and dispersed throughout the planet if the planet is hot enough. In "traditional" giant planets such as Jupiter and Saturn (the gas giants) hydrogen and helium constitute most of the mass of the …

Theia is een speculatieve planeet die volgens een theorie meer dan vier miljard jaar geleden, voorafgaand aan de formatie van de Maan, is ingeslagen op de Aarde.Deze inslag vernietigde Theia en gooide grote hoeveelheden materiaal in een baan om de Aarde, waaruit vervolgens de Maan is ontstaan in een periode van waarschijnlijk enkele duizenden jaren. De Aarde kreeg …

A 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, since they are possibly differentiated and geologically active bodies, they may display planetary geology, an …

Earth is the third planet from the Sun and the only astronomical object known to harbor life.While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water.About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers.The remaining 29% of Earth's surface is land, consisting of continents and …

Eons. In geochronology, time is generally measured in mya (million years ago), each unit representing the period of approximately 1,000,000 years in the past.The history of Earth is divided into four great eons, starting 4,540 mya with the formation of the planet.Each eon saw the most significant changes in Earth's composition, climate and life. Each eon is subsequently …