Study turns back clock on origins of life on Earth
By Julie Steenhuysen | Reuters.com
The bombardment of Earth by asteroids 3.9 billion years ago may have enhanced early life, according to a new University of Colorado study. Credit: NASA/JPL
A heavy bombardment by asteroids the size of Ireland was not enough to wipe out life on Earth 3.9 billion years ago, researchers said on Wednesday in a finding that turns back the clock of life by 500 million years.
Many scientists had thought the violent pelting by massive asteroids during the period known as the Late Heavy Bombardment would have melted the Earth's crust and vaporized any life on the planet.
But new three-dimensional computer models developed by a team at the University of Colorado at Boulder shows much of Earth's crust, and the microbes living on it, could have survived and may even have thrived.
"These new results push back the possible beginnings of life on Earth to well before the bombardment period 3.9 billion years ago," said Oleg Abramov, a researcher at the university whose study appears in the journal Nature.
"It opens up the possibility that life emerged as far back as 4.4 billion years ago, about the time the first oceans are thought to have formed," Abramov said in a statement.
To study this period, Abramov and colleague Stephen Mojzsis used data from moon rocks, meteorite samples and the dented surfaces of neighboring planets to develop a three-dimensional model of this period of bombardment.
"What we did was recreate the Late Heavy Bombardment on a computer," Abramov said, adding that the simulation randomly "smacked the Earth" with giant asteroids.
The team then looked at the impact that would have had on the Earth's temperature in the so-called geophysical habitable zone -- a zone representing the top 2.5 miles of the Earth's crust.
Based on these models, Abramov said this sustained period of impacts would have killed any life on the Earth's surface, but not all life on Earth, as many had assumed.
"We find it is essentially impossible to sterilize the entire habitable zone of the Earth by this kind of bombardment," Abramov said in a telephone interview.
"Certainly, the surface of the Earth was sterilized repeatedly," he said.
But he said hydrothermal vents below the surface of the Earth may have offered sanctuaries for certain heat-loving microbes, and may have even provided a kind of incubator for life.
He said many scientists had thought that a cataclysmic bombardment event would have sterilized the planet and life would have had to start anew.
"The important thing about these results is they push back the possible beginnings of life as we know it," he said.
"Exactly when life originated on Earth is a hotly debated topic," said Michael New, an astrobiologist at the National Aeronautics and Space Administration, which sponsored the research.
"These findings are significant because they indicated life could have begun well before the Late Heavy Bombardment, during the so-called Hadean Eon of Earth's history 3.8 billion to 4.5 billion years ago," New said in a statement.
(Editing by Michael Conlon and Doina Chiacu)
Article from: www.Reuters.com
Dinosaur Killer May Have Been Volcanism, Not Asteroid
New Insight into Earth's Early Bombardment
Holes in the Earth: 170 and Counting
Greatest Mysteries: How Did Life Arise on Earth?
The Asteroid Paradox: Harm or Help? [Video]
Latest News from our Front Page
The Divorce Industry
Yes, that’s right. The “Divorce Industry”. There is an actual industry dedicated to making large sums of money off of people’s divorces. A 50 billion dollar industry to be exact. Unfortunately, I’m not too shocked about this one. What I was shocked about, however, was the amount of people that are using these “services”.
I’m sure ...
An Open Letter to #Cuckservatives
You aren’t just betraying your principles.
You are not alone. Like you, Erick Erickson at RedState.com, Matt Lewis at the Daily Caller, Taylor Millard at Hot Air, the blogger Ace of Spades, and Jim Harper with the Cato Institute are all squirming under the lash of this new coinage. They are squirming because a single word–cuckservative–lays bare the rot at the ...
Aurora Shooting Victim Parents Face $200K Court Fees, Bankruptcy, After Failing to Sue Ammo Dealers
The 2012 Colorado Theater Shooting still doesn’t add up…
Media character and ‘Shooter’ James Holmes in court in 2012-2013.
In 2014, Sandy and Lonnie Phillips, the mother and stepfather of Aurora Theater Shooting victim Jessica Redfield Ghawi, tried to sue the ammo companies they believe supplied shooter James Holmes with his ammunition, body armor and other items. They bleived that the online retailer BulkAmmo.com had sold Holmes ...
FBI's Joint Terrorism Task Force Investigating Confederate Flags at MLK's Ebenezer Baptist Church
According to the Atlanta Police Department, two White men left four small Confederate Battle Flags outside MLK’s Ebenezer Baptist Church in Atlanta … and get this, the FBI’s Joint Terrorism Task Force is on the scene investigating the incident.
Atlanta police Chief George Turner said his agency was working with federal authorities and they have not determined what charges might be ...
Democratic National Committee Chair Wasserman Schultz Can’t Explain Difference Between Democrat Party and Socialism
Things got very awkward today when Chris Matthews asked DNC Chair Debbie Wasserman Schultz what the difference was between the modern Democratic Party and Socialism.
We haven’t seen that dazed look since Rachel Dolezal was busted as a fraud.
Wasserman Schultz was speechless.
Then changed the subject.
Because we all know there is no difference between today’s Democrat Party and the radical ...
|More News » |