Latest News: Technology |  Celebrity |  Movies |  Apple |  Cars |  Business |  Sports |  TV Shows |  Geek


Filed under: News


Life On Earth Didn't Begin On Mars, Says Astrochemist

Dec 27 2013, 5:06am CST | by

10 Updates
Life On Earth Didn't Begin On Mars, Says Astrochemist
Photo Credit: Forbes


Recommend Your Tweet as Top Tweet:

Full Story

Life On Earth Didn't Begin On Mars, Says Astrochemist

The eternal chicken or egg question — did Mars seed life on earth or did earth seed life on the Red Planet? — is utter astrobiological “nonsense.”

Or so says Pascale Ehrenfreund, an astrochemist at George Washington University in Washington , D.C.

Ehrenfreund says that there are two major arguments against “panspermia” (or the notion that microbial life could spread from one planetary body to another).

The first is simply that both ultraviolet radiation from the sun and galactic cosmic rays would likely destroy microbial life in the unprotected vacuum of space. The second is that, even if such life survived a journey from Mars to earth, among other factors, its survival would also likely depend on entry through a roiling, young planetary atmosphere and adaptation to its new home.

Thus, Ehrenfreund views any “We are Martians” scenario as “highly unlikely.”/>/>

So, did early life here get a crucial boost from complex molecules from beyond our forming solar system, or even from our young solar nebula itself?

Ehrenfreund says that although molecules like hydrogen cyanide, formaldehyde and water all form in the interstellar medium, prebiotic chemistry really involves replication and structure.

“I don’t think this happens anywhere in [free-floating] space itself,” said Ehrenfreund.

Even so, to date, some 180 different molecular species have been detected in space.

In their gas phase, Polycyclic Aromatic Hydrocarbons (PAHs) which on earth encompass everything from naphthalene, the active ingredient in mothballs, to chimney soot, pine tar, even the “char” residue found on backyard grills, appear to be ubiquitous throughout the universe.

Some estimates are that PAHs make up some 15 percent of the cosmos’ total carbon supply. But how important are they for our own chemistry on earth?

Ehrenfreund says PAHs, as well as solid macromolecules, did make it to earth’s surface, because they were more stable and abundant and may have decayed into smaller subunits incorporated into primitive protocells.

But she says small biomolecules such as amino acids and sugars are fragile and likely were easily destroyed by radiation and high temperatures prevalent on the young earth.

Even so, Ehrenfreund says complex molecules and gases which form in the interstellar medium will be included in the solar nebula, as such, they are precursors for prebiotic chemistry that may have contributed to life on earth.

Ehrenfreund says that via meteoritic analysis, there is now ample evidence that processes involving water on asteroids can form new organic compounds such as amino acids.

She points out that an incredible amount of material, including a tiny fraction of amino acids, was delivered through earth’s atmosphere. But Ehrenfreund says most researchers think that amino acids found in meteorites didn’t form in the Interstellar Medium but rather from water processes in the parent body asteroid.

There is still no undisputed detection of an amino acid in the interstellar medium.

“We have the first undebated indications of life at 3.5 billion years ago,” said Ehrenfreund, who notes that the inner solar system’s epoch of asteroidal and cometary Late Heavy Bombardment, ended about 3.9 billion years ago. But even after such an epoch of impactors, she says our young earth was still plagued by a very violent and hostile surface environment.

The biggest mystery is what basic compounds were available that could also assemble under such inhospitable conditions?

“That’s a key point in the origin of life,” said Ehrenfreund. “That’s a crucial point on which we have a real gap.”

Did these ubiquitous PAHs make the crucial difference in prebiotic chemistry for life?

Ehrenfreund notes that even though researchers now realize that complex carbon chemistry is universal, they are much less knowledgeable about what happens to such chemistry after an interstellar cloud collapses and forms a planetary system.

That’s because what’s really important for the origin of life on earth and by rote, other earthlike planets, is what is actually delivered from extraterrestrial sources.

Although there’s a whole subgroup of microbiologists trying to create artificial life in the lab, says Ehrenfreund, none of these researchers are trying to recreate the assembly of protocells in a simulated early earth environment.

Why not?

“It’s intrinsically very difficult because there’s a lot of debate about what the conditions actually were,” said Ehrenfreund.

And biotech researchers trying to construct protocells for potential use in contemporary medicine have arguably vastly different goals than astrochemists and astrobiologists.

Partly as a result, Ehrenfreund says that although biotech funding is readily available, it’s very difficult to get funding and grants for research into earth’s early prebiotic chemistry.

No one has tried to create a protocell under early earth conditions, she says.

“There are lots of ongoing Mars simulations,” said Ehrenfreund. “But we do much less for simulations of early earth.”

Answering such fundamental questions about life’s origins on earth, she says, will require astronomers, geologists and chemists working with simulation chambers that include fluctuations in early earth changes in temperatures, atmospherics, radiation and hydrothermal conditions.

“We would be able to see which [prebiotic] components could self-assemble and which could not,” said Ehrenfreund. “We could then extrapolate from where those compounds came.”

Follow me on Facebook , Twitter and Google + .

Source: Forbes


iPad Air Giveaway. Win a free iPad Air.

You Might Also Like


Sponsored Update

Update: 10

GLCs told to provide RM7 billion to develop Bumiputera firms

Source: Malaysia Today

EurAsia Cup presented by DRB-HICOM - Day One
(The Malaysian Insider) – Putrajaya has directed government-linked companies (GLC) to generate RM7 billion in business opportunities for Bumiputera firms this year, Prime Minister Prime Minis ...
Source: Malaysia Today   Full article at: Malaysia Today 5 days ago, 2:05am CDT


Update: 9

Rafizi shows proof of Putrajaya’s hand in contentious carpet-trader loan

Source: Malaysia Today

Eileen Ng, The Malaysian Insider PKR lawmaker Rafizi Ramli today revealed documents to prove Putrajaya interfered in the RM32 million Bank Rakyat loan to ‎controversial businessman Deep ...
Source: Malaysia Today   Full article at: Malaysia Today 6 days ago, 2:16am CDT

More From the Web

Update: 8

PAS MP claims Bank Rakyat loaned carpet-trader RM215m, interest free

Source: Malaysia Today

(Malay Mail Online) – Controversial businessman Deepak Jaikishan (pic) was given a whopping RM215 million interest-free loan from state-owned Bank Rakyat, a PAS lawmaker alleged today, despite Putrajaya’s clai ...
Source: Malaysia Today   Full article at: Malaysia Today Jul 14 2014, 5:52am CDT

Update: 7

MRCB, Nusa Gapurna and PKNS settle suit over RM3 billion PJ Sentral project

Source: Malaysia Today

(The Malaysian Insider) – Malaysian Resources Corp Bhd (MRCB), Nusa Gapurna Development Sdn Bhd (NGD) and PKNS Holdings Sdn Bhd have reached an out-of-court settlement over ...
Source: Malaysia Today   Full article at: Malaysia Today Jun 21 2014, 2:53am CDT

Update: 6

Story behind Syed Mokhtar’s ‘RM2.25 billion tax-exempt’ Bernas deal revealed, says PKR MP

Source: Malaysia Today

(The Malaysian Insider) – An innocuous written reply in Parliament has provided a peek into the cosy relationship between the Najib administration and Malaysia’s best-known businessman, ...
Source: Malaysia Today   Full article at: Malaysia Today Jun 15 2014, 12:56pm CDT

Update: 5

Constitutional monarchy still murky concept

Source: Malaysia Today

After the RM4.5 billion land sale, the Sultan of Johor secured a 15% stake in MOL Access Portal (MOL) for RM396 million and took a 20% stake in Berjaya Times... READ MO ...
Source: Malaysia Today   Full article at: Malaysia Today Jun 14 2014, 12:37am CDT

Update: 4

Sultan of Johor’s RM4.5 bil backlash?

Source: Malaysia Today

"GOLDEN ASIA" Tokyo Premiere Press Conference
Has Sultan Ibrahim of Johor’s succession of big money deals over the last six months caused the tide of public opinion to turn against Johor’s royal palace? KiniBiz examines the... READ M ...
Source: Malaysia Today   Full article at: Malaysia Today Jun 11 2014, 8:49am CDT

Update: 3

Putrajaya denies carpet dealer given interest-free loan

Source: Malaysia Today

Eileen Ng, The Malaysian Insider Putrajaya today refuted allegations that Bank Rakyat had allowed carpet dealer Deepak Jaikishan to repay a RM32 million loan without interest following intervention fr ...
Source: Malaysia Today   Full article at: Malaysia Today Jun 11 2014, 5:44am CDT

Update: 2

Malaysia Spends Over $9 million on MH370 Hunt: Report

Source: NDTV

"GOLDEN ASIA" Tokyo Premiere Press Conference
Malaysia has so far spent about RM27.6 million (over $9 million) on search operations for missing Malaysia Airlines flight MH370, an official said ...
Source: NDTV   Full article at: NDTV Jun 9 2014, 3:12am CDT

Update: 1

Bill for Kidex likely to soar to RM3.4b

Source: Malaysia Today

The original RM2.4 billion tag on the proposed highway did not take into account the cost of acquiring the land mostly in the urban areas, claims an assemblywoman Fabian Comelius,... ...
Source: Malaysia Today   Full article at: Malaysia Today Jun 9 2014, 2:51am CDT

Shopping Deals


<a href="/latest_stories/all/all/31" rel="author">Forbes</a>
Forbes is among the most trusted resources for the world's business and investment leaders, providing them the uncompromising commentary, concise analysis, relevant tools and real-time reporting they need to succeed at work, profit from investing and have fun with the rewards of winning.




blog comments powered by Disqus

Latest stories

Apple reports $7.7 billion profit fueled by strong iPhone sales
Apple reports $7.7 billion profit fueled by strong iPhone sales
Apple's third quarter revenue is $37.4 billion - up from last year's $35.3 billion. Quarterly net profit is $7.7 billion, an increase from the previous $6.9 billion net profit.
Johnny Manziel's Jersey is NFL's Top Seller
Johnny Manziel's Jersey is NFL's Top Seller
Cleveland Browns rookie quarterback Johnny Manziel's jersey is the NFL's top seller.
Baltimore Orioles Hope Ubaldo Jimenez Returns Soon
Baltimore Orioles Hope Ubaldo Jimenez Returns Soon
The Baltimore Orioles hope starting pitcher Ubaldo Jimenez, who hasn't taken the mound since July 5 due to a sprained right ankle, can return soon.
David Ortiz Moves Up to 36th All-Time in Home Runs
David Ortiz Moves Up to 36th All-Time in Home Runs
Boston Red Sox designated hitter David Ortiz homered twice in his team's 14-1 rout of the Toronto Blue Jays on July 21 to move up to 36th all-time in home runs, surpassing Red Sox legend Carl Yastrzemski.

About the Geek Mind

Read more about The Geek Mind.