oxygen was the gas that most likely was not part of earth's early atmosphere.
oxygen was the gas that most likely was not part of earth's early atmosphere.
which gas most likely was not part of earth's early atmosphere?
oxygen
the geological time scale (gts), as defined by international convention, depicts the large spans of time from the beginning of the earth to the present, and its divisions chronicle some definitive events of earth history. (in the graphic: ga means "billion years ago"; ma, "million years ago".) earth formed around 4.54 billion years ago, approximately one-third the age of the universe, by accretion from the solar nebula. volcanic outgassing probably created the primordial atmosphere and then the ocean, but the early atmosphere contained almost no oxygen. much of the earth was molten because of frequent collisions with other bodies which led to extreme volcanism. while the earth was in its earliest stage (early earth), a giant impact collision with a planet-sized body named theia is thought to have formed the moon. over time, the earth cooled, causing the formation of a solid crust, and allowing liquid water on the surface.
history of earth
tentative constraints are available, with the current loss mostly due to low gravity and solar wind aided by photolysis. the loss of titan's early atmosphere can be estimated with the n–n isotopic ratio, because the lighter n is preferentially lost from the upper atmosphere under photolysis and heating. because titan's original n–n ratio is poorly constrained, the early atmosphere may have had more n by factors ranging from 1.5 to 100 with certainty only in the lower factor. because n is the primary component (98%) of titan's atmosphere, the isotopic ratio suggests that much of the atmosphere has been lost over geologic time. nevertheless, atmospheric pressure on its surface remains nearly 1.5 times that of earth as it began with a proportionally greater volatile budget than earth or mars. it is possible that most of the atmospheric loss was within 50 million years of accretion, from a highly energetic escape of light atoms carrying away a large portion of the atmosphere (hydrodynamic escape). such an event could be driven by heating and photolysis effects of the early sun's higher output of x-ray and ultraviolet (xuv) photons.
atmosphere of titan