Stanley Miller's classic "primordial soup" experimental setup,
with a simulated ocean, lightning and broth
of hydrogen, methane, ammonia and water.
Posted on 04/08/2005 7:39:14 AM PDT by PatrickHenry
A new University of Colorado at Boulder study indicates Earth in its infancy probably had substantial quantities of hydrogen in its atmosphere, a surprising finding that may alter the way many scientists think about how life began on the planet.
Published in the April 7 issue of Science Express, the online edition of Science Magazine, the study concludes traditional models estimating hydrogen escape from Earth's atmosphere several billions of years ago are flawed. The new study indicates up to 40 percent of the early atmosphere was hydrogen, implying a more favorable climate for the production of pre-biotic organic compounds like amino acids, and ultimately, life.
The paper was authored by doctoral student Feng Tian, Professor Owen Toon and Research Associate Alexander Pavlov of CU-Boulder's Laboratory for Atmospheric and Space Physics with Hans De Sterk of the University of Waterloo. The study was supported by the NASA Institute of Astrobiology and NASA's Exobiology Program.
"I didn't expect this result when we began the study," said Tian, a doctoral student in CU-Boulder's Astrobiology Center at LASP and chief author of the paper. "If Earth's atmosphere was hydrogen-rich as we have shown, organic compounds could easily have been produced."
Scientists believe Earth was formed about 4.6 billion years ago, and geologic evidence indicates life may have begun on Earth roughly a billion years later.
"This study indicates that the carbon dioxide-rich, hydrogen-poor Mars and Venus-like model of Earth's early atmosphere that scientists have been working with for the last 25 years is incorrect," said Toon. In such atmospheres, organic molecules are not produced by photochemical reactions or electrical discharges.
Toon said the premise that early Earth had a CO2-dominated atmosphere long after its formation has caused many scientists to look for clues to the origin of life in hydrothermal vents in the sea, fresh-water hot springs or those delivered to Earth from space via meteorites or dust.
The team concluded that even if the atmospheric CO2 concentrations were large, the hydrogen concentrations would have been larger. "In that case, the production of organic compounds with the help of electrical discharge or photochemical reactions may have been efficient," said Toon.
Amino acids that likely formed from organic materials in the hydrogen-rich environment may have accumulated in the oceans or in bays, lakes and swamps, enhancing potential birthplaces for life, the team reported.
The new study indicates the escape of hydrogen from Earth's early atmosphere was probably two orders of magnitude slower than scientists previously believed, said Tian. The lower escape rate is based in part on the new estimates for past temperatures in the highest reaches of Earth's atmosphere some 5,000 miles in altitude where it meets the space environment.
While previous calculations assumed Earth's temperature at the top of the atmosphere to be well over 1,500 degrees F several billion years ago, the new mathematical models show temperatures would have been twice as cool back then. The new calculations involve supersonic flows of gas escaping from Earth's upper atmosphere as a planetary wind, according to the study.
"There seems to have been a blind assumption for years that atmospheric hydrogen was escaping from Earth three or four billion years ago as efficiently as it is today," said Pavlov. "We show the escape was limited considerably back then by low temperatures in the upper atmosphere and the supply of energy from the sun."
Despite somewhat higher ultraviolet radiation levels from the sun in Earth's infancy, the escape rate of hydrogen would have remained low, Tian said. The escaping hydrogen would have been balanced by hydrogen being vented by Earth's volcanoes several billion years ago, making it a major component of the atmosphere.
In 1953, University of Chicago graduate student Stanley Miller sent an electrical current through a chamber containing methane, ammonia, hydrogen and water, yielding amino acids, considered to be the building blocks of life. "I think this study makes the experiments by Miller and others relevant again," Toon said. "In this new scenario, organics can be produced efficiently in the early atmosphere, leading us back to the organic-rich soup-in-the-ocean concept."
In the new CU-Boulder scenario, it is a hydrogen and CO2-dominated atmosphere that leads to the production of organic molecules, not the methane and ammonia atmosphere used in Miller's experiment, Toon said.
Tian and other team members said the research effort will continue. The duration of the hydrogen-rich atmosphere on early Earth still is unknown, they said.
"Are you sayign that it's the common consensus? You assume much, young padawan."
If you read the very next sentance you just quoted you will see me say I know not everyone believes this. Give me a break.
According to the greatest scientific minds, something, a conciseness, a word, had to have started it all. The rest is our own free will (that's in the Bible, too).
You remind me of myself 6 years ago. Full of stupid answers and incomplete thoughts. I still have some, but I'm no longer full of them.
THINK for just a minute before you post what you do.
If life came from non-life (in the building block sense) then how did it get organized? We are yet to witness it happen. Life came from something else "coaxing" it along.
"Any Bible thumper knows life didn't come from nothing. It even suggests that life came from non-living things. But another being was required to form it."
MacDorcha is saying exactly that. So please explain this to them.
Yeah, its great!
These amino acids "evolve" into single cell animals who later "invent" sex.
Over time they adapt and specialize into all of the species we have today.
That's "science"?
"If life came from non-life (in the building block sense) then how did it get organized?"
It became organized by the right chemical mix, with the right temperature and pressure billions of years of time and many many other factors.
If life did not spring from non-life where did it come from?
You may have been quite stupid 6 years ago as you say, but please don't compare yourself to me.
you said "not everyone" you didn't say "almost noone" or "only the undereducated"
You implied that it was common for Christians to believe the world was made in 6 days, and that anyone who reads the Bible would suppose that life came from nothing.
It is actually rare for that to be the case, and yuo just presented an ignorant view of the Christian World.
Again, THINK for just one more minute before you post.
"Yeah, its great!
These amino acids "evolve" into single cell animals who later "invent" sex.
Over time they adapt and specialize into all of the species we have today.
That's "science"?"
Since my ideas are so funny? Lets hear your explanation.
"If life did not spring from non-life where did it come from?
You may have been quite stupid 6 years ago as you say, but please don't compare yourself to me."
That is EXACTLY me 6 years ago! LOL!
"It became organized by the right chemical mix, with the right temperature and pressure billions of years of time and many many other factors. "
Then provide the right environment for this to happen. You can synthesize pressure and you can speed up the processes of reactions and atomic speed. I'll wait.
MacDorcha,
Where did life come from?
BTW, it's worth adding that I haven't dismissed the possibility that god/s might exist, I've just dismissed the notion that the answer can be found through reason. If God does exist, then to date he's clearly seen fit to conceal that fact from me.
"Then provide the right environment for this to happen. You can synthesize pressure and you can speed up the processes of reactions and atomic speed. I'll wait."
Oh its happening in millions of places as we speak. I didn't realize scientists had the ability to make billions of years pass in a few weeks.
I don't know if you're trying to be funny, but I posted that.
Read the Bible. The first book. Show me where it says that life came directly from nothing (magical wand of the Big Buy)
God made matter, then with that matter, God made Man.
::sigh:: your blind faith is silly and petty. Talk to me once you have your fist kiss. Maybe you'll be more grown up by then.
I'll go with that. Keep an open mind though, there will be a quiz later :)
Oh more name calling from a person who cannot or will not answer a simple question. I'm shocked utterly shocked.
Life came from God. God is Truth.
Where did the laws conerning how matter coem from arise?
And the polls also said John Kerry was going to win the election.
The reason there's overwhelming support for evolution is:
Atheist rule the scientific institutions.
It's taught to those who are unaware there are other choices just as factual.
"Modern Science" started with the old alchemist who hated the Catholic Church. The Church frowned on their use of the black magic. What they were doing was studying quantum psychics, but masked what they were doing by acting like mad men trying to turn matter into gold. The rest of science spun off the ant-Church agenda.
To this very day, they spend their lives and monies to prove there is no God, and thousands of years later they still have nothing.
Unfortunately for the old alchemists, the very science they were using to disprove an existence of God has the exact opposite conclusion! Something with a conciseness had to have started it all! LOL.
Until you can offer a better hypothesis of where life came from I will stick with my conclusion that life emerges on planets with suitable conditions.
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