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The nebular hypothesis is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System (as well as other planetary systems). It suggests the Solar System is formed from gas and dust orbiting the Sun which clumped up together to form the planets.
The nebular hypothesis says that the Solar System formed from the gravitational collapse of a fragment of a giant molecular cloud, [9] most likely at the edge of a Wolf-Rayet bubble. [10] The cloud was about 20 parsecs (65 light years) across, [9] while the fragments were roughly 1 parsec (three and a quarter light-years) across. [11]
The history of scientific thought about the formation and evolution of the Solar System began with the Copernican Revolution. The first recorded use of the term " Solar System " dates from 1704. [ 1 ] [ 2 ] Since the seventeenth century, philosophers and scientists have been forming hypotheses concerning the origins of the Solar System and the ...
The Andromeda Galaxy, for instance, was once 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, and others. Edwin Hubble discovered that most nebulae are associated with stars and illuminated by starlight.
The chronology of the universe describes the history and future of the universe according to Big Bang cosmology.. Research published in 2015 estimates the earliest stages of the universe's existence as taking place 13.8 billion years ago, with an uncertainty of around 21 million years at the 68% confidence level.
The nature of the dust particles, reflecting blue light better than red, is a factor in giving the Witch Head its blue color. Radio observations show substantial carbon monoxide emission throughout parts of IC 2118, an indicator of the presence of molecular clouds and star formation in the nebula.
It is approximately 2,500 light-years away. NGC 6326 , a planetary nebula with glowing wisps of outpouring gas that are lit up by a binary [ 3 ] central star A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.
It was composed of hydrogen and helium created shortly after the Big Bang 13.8 Ga (billion years ago) and heavier elements ejected by supernovae. About 4.5 Ga, the nebula began a contraction that may have been triggered by the shock wave from a nearby supernova. [23] A shock wave would have also made the nebula rotate.