Sentences with phrase «early atmosphere»

This creates a stumbling block for those who thought the solution to the faint sun paradox lay in a dense early atmosphere.

Furthermore, it is likely that Miller and Urey erred by simulating Earth's early atmosphere with gases containing hydrogen, which reacts easily, as opposed to carbon dioxide, a gas that is far less reactive but was probably far more plentiful at the time.

Measurements of heavy - versus - light variants of elements in the Martian atmosphere indicate that much of Mars» early atmosphere disappeared by processes favoring loss of lighter atoms, such as from the top of the atmosphere.

This hint of more oxygen in Mars» early atmosphere adds to other Curiosity findings — such as evidence about ancient lakes — revealing how Earth - like our neighboring planet once was.

If the carbon dioxide sprang from a geothermal source, it would not provide much information about Mars's early atmosphere as claimed by the new study, Catling says.

The hot early atmosphere probably contained methane too, Lowe says.

The interpretation is that the atmosphere of Mars was thicker and warmer in former times, and perhaps much like the Earth's early atmosphere before the appearance of oxygen.

Studying this complex chemistry may provide insights into the properties of Earth's very early atmosphere, which may have shared many chemical characteristics with present - day Titan.

If lowly bluegreen algae can change our early atmosphere from reducing to oxidizing, then why can't humans also affect climate?

Fifty years ago last summer, chemist Stanley Miller demonstrated that electric sparks passing through a simulation of Earth's early atmosphere and oceans trigger the formation of amino acids, building blocks of proteins.

There's no proof that was the case, Kasting says, and some preliminary modeling experiments have suggested that carbon dioxide dominated the early atmosphere.

The results suggest that Earth's early atmosphere could have produced chemicals necessary for life — contradicting the view that life's building blocks had to come from comets and meteors.

Nitrogen gas (N2) is thought to have been abundant in the early atmosphere, but it's largely nonreactive and therefore an unlikely source.

Today, many scientists argue that the early atmosphere was dominated by other gases, such as carbon dioxide.

Over the past 40 years, researchers have thought that there must have been a small amount of oxygen in the early atmosphere.

Previous modelling efforts to resolve the paradox by loading the early atmosphere with greenhouse gases assumed that it has always had the same concentration of nitrogen.

Our planet's early atmosphere was rich in methane and carbon dioxide and had only very low levels of O2.

Scientists think that billions of years ago the sun may have burned off Earth's early atmosphere in the same way it is now blowing off Pluto's.

Even if Proxima Centauri b is in the habitable zone, it could have had an early atmosphere ripped away by the first billion years of violent stellar activity common with red dwarfs.

Once these planets migrate in, their star strips off the early atmosphere of lighter elements.

This indicates that the early atmosphere must have contained greenhouse gases in addition to carbon dioxide.

The surprising success of the Miller - Urey experiment has made it a classic in many textbooks, but there was also a problem at its core — namely, Urey's hypothesis that the early atmosphere was flush with methane and ammonia.

But with little oxygen in the early atmosphere, ancient microbes evolved a very different chemical pathway to break down orthophosphate into phosphite, a reduced form of phosphorus that has just three oxygens.

Geologists know that the early atmosphere contained carbon dioxide because carbonate rocks, formed when carbon dioxide reacts with minerals, were laid down at least 3.8 billion years ago.

Earth's early atmosphere and oceans were devoid of free oxygen, even though tiny cyanobacteria were producing the gas as a byproduct of photosynthesis.

The problem was that theoretical models and analyses of ancient rocks eventually convinced scientists that Earth's earliest atmosphere was not rich in hydrogen.

For the research team, one of the most - exciting aspects of this finding is the potential of a reservoir of oxygen deep in the planet's interior, which if periodically released to Earth's surface could significantly alter Earth's early atmosphere, potentially explaining the dramatic increase in atmospheric oxygen that occurred about 2.4 billion years ago according to the geologic record.

Consistent with this scenario, research published online March 18 in Nature Geoscience suggests that the early atmosphere cycled through periods of a «hydrocarbon haze» that included potent greenhouse gases like methane.

By using lasers to scan the craters — and comparing the indentations with those created today — astrobiologist Sanjoy Som of the NASA Ames Research Center and his colleagues have derived a measurement of the pressure exerted by the early atmosphere.

But even more surprising, say the Stanford scientists who report these findings in the May 25 issue of the journal Geology, is the critical role that rocks played in the evolution of the early atmosphere.

«This is really the first time we've tried to put together a picture of how the early atmosphere, early climate and early continental evolution went hand in hand,» said Donald R. Lowe, a professor of geological and environmental science who wrote the paper with Michael M. Tice, a graduate student investigating early life.

To piece together geologic clues about what the early atmosphere was like and how it evolved, Lowe, a field geologist, has spent virtually every summer since 1977 in South Africa or Western Australia collecting rocks that are, literally, older than the hills.

The geologic record tells a story in which continents removed the greenhouse gas carbon dioxide from an early atmosphere that may have been as hot as 70 degrees Celsius (158 F).

One reason is that geologists changed their minds about the composition of the earth's early atmosphere.

After all green plants and plankton oxygenated the early atmosphere of Earth, creating an environment that allowed new life forms to emerge.

For the research team, one of the most - exciting aspects of this finding is the potential of a reservoir of oxygen deep in the planet's interior, which if periodically released to the Earth's surface could significantly alter the Earth's early atmosphere, potentially explaining the dramatic increase in atmospheric oxygen that occurred about 2.4 billion years ago according to the geologic record.

And that's why many scientists had argued photosynthesis must have been behind the buildup of oxygen in Earth's early atmosphere.

Where did the carbon dioxide go from an early atmosphere?»

The results quantify the nature of gas molecules containing carbon, hydrogen, and sulfur in the earliest atmosphere, but they shed no light on the much later rise of free oxygen in the air.

Space Comet are thought to have created major changes to Earth's early atmosphere and climate by striking Earth billions of years ago.

After all green plants and plankton oxygenated the early atmosphere of Earth, creating an environment that allowed new life forms to emerge.

Wordsworth R and Pierrehumbert RT 2013: Hydrogen - nitrogen greenhouse warming in Earth's early atmosphere.

In the early atmosphere / ocean computer models they simply assumed a «swamp» approach of 100 percent evaporation.

We know this because the earth's early atmosphere was similar to Venus».