According to the Solar Nebular Disk Model, rocky planets form in the inner part of the protoplanetary disk, within the frost line, where the temperature is high enough to prevent condensation of water ...
Main article: History of Solar System formation and evolution hypothesesThere is evidence that the nebular hypothesis was first proposed in 1734 by Emanuel Swedenborg. Immanuel Kant, who was familiar ...
Some unstable isotopes which occur naturally (such as 14C, 3H, and 239Pu) are not primordial, as they must be constantly regenerated. This occurs by cosmic radiation (in the case of cosmogenic nuclide ...
Cosmic dust is made of dust grains and aggregates of dust grains. These particles are irregularly shaped, with porosity ranging from fluffy to compact. The composition, size, and other properties depe ...
Study and importance Cosmic dust was once solely an annoyance to astronomers, as it obscures objects they wish to observe. When infrared astronomy began, those previously annoying dust particles were ...
Main article: Protoplanetary diskAccording to the currently accepted model of star formation, sometimes referred to as the nebular hypothesis, a star is formed by the gravitational collapse of a pocke ...
Within the Milky Way, molecular gas clouds account for less than one percent of the volume of the interstellar medium (ISM), yet it is also the densest part of the medium, comprising roughly one-half ...
The various planets are thought to have formed from the solar nebula, the disc-shaped cloud of gas and dust left over from the Sun's formation. The currently accepted method by which the planets forme ...
In the long term, the greatest changes in the Solar System will come from changes in the Sun itself as it ages. As the Sun burns through its supply of hydrogen fuel, it gets hotter and burns the remai ...
Main article: History of Solar System formation and evolution hypothesesPierre-Simon Laplace, one of the originators of the nebular hypothesisIdeas concerning the origin and fate of the world date fro ...
In astrophysics, accretion is the growth of a massive object by gravitationally attracting more matter, typically gaseous matter in an accretion disk. Accretion disks are common around smaller stars o ...
Main article: PhanerozoicThe Phanerozoic is the current eon on Earth, which started approximately 542 million years ago. It consists of three eras: The Paleozoic, Mesozoic, and Cenozoic, and is the ti ...
Main article: Geologic time scaleThe history of the Earth is organized chronologically in a table known as the geologic time scale, which is split into intervals based on stratigraphic analysis. A ful ...
Lovelock has suggested that global biological feedback mechanisms could evolve by natural selection, stating that organisms that improve their environment for their survival do better than those that ...
Gaian hypotheses suggest that organisms co-evolve with their environment: that is, they "influence their abiotic environment, and that environment in turn influences the biota by Darwinian process". L ...
