Lab study adds credence to life arriving on Earth from asteroids theory

December 19, 2018 by Bob Yirka, Phys.org report
This enormous mosaic of the Milky Way galaxy from NASA's Wide-field Infrared Survey Explorer, or WISE, shows areas of interstellar space where dozens of dense clouds, called nebulas, are forming into new stars. Credit: NASA

A team of researchers at NASA's Ames Research Center has found some evidence that adds credence to the theory that the basic ingredients for life came to Earth from asteroids. In their paper published in the journal Nature Communications, the group describes the experiments they carried out, what they found, and why they believe their work offers evidence of life arriving from elsewhere.

Despite a lot of effort, scientists still do not know how life started on planet Earth. They also do not know if it sprang out of existing ingredients or if those ingredients came from somewhere else, via asteroid or comet. There are two current leading theories. The first suggests that life began in a hot spring on land or in a deep-sea thermal vent, because the right mix of ingredients were there to allow it to happen. The other main theory suggests that the basic ingredients for life arrived on a comet or asteroid and things took off from there. In this new effort, the researchers have found some evidence that supports the latter theory.

One of the main ingredients of life is sugar—it provides energy. One kind of sugar, 2-deoxyribose, is the component in DNA. In their lab, the researchers created space-like conditions and found they were sufficient for spontaneously creating 2-deoxyribose. More specifically, they put a sample of an aluminum substrate in a freezer, cooling it down to near absolute zero. They then placed it in a vacuum chamber. That allowed for simulating conditions in deep space. Next, the team piped in a water and methanol gas mixture, similar to that found in the interstellar medium. To simulate radiation from stars, they bathed the sample in UV light.

The researchers report that initially, ice built up on the sample, but it was melted by the UV light. The team found that a small amount of 2-deoxyribose had formed along with some other sugars. Intrigued by their findings, the researchers examined samples from several carbonaceous meteorites that have been found over the years and found of alcohols and deoxysugar acids—not exactly 2-deoxyribose, but the researchers note that their sampling was small—it might be found on others.

In the Astrophysics and Astrochemistry Lab at NASA's Ames Research Center researchers Michel Nuevo, Christopher Materese and Scott Sandford study the cosmic origins of molecules that are important to life. Credit: NASA/Ames Research Center/Dominic Hart

The researchers suggest that their findings add yet more credence to the that the basic ingredients for came to us from elsewhere, and only required the right conditions to make the jump from a cocktail of chemicals to living creatures.

Explore further: New evidence that comets deposited building blocks of life on primordial Earth

More information: Michel Nuevo et al. Deoxyribose and deoxysugar derivatives from photoprocessed astrophysical ice analogues and comparison to meteorites, Nature Communications (2018). DOI: 10.1038/s41467-018-07693-x

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heyheybo
3.3 / 5 (6) Dec 19, 2018
Organic compunds and water are everywhere. I really dont understand what is the difference if organics molecules can be created in space, if a)the same compounds can be created on earth after long term chemical reactions, b)primordial earth was very different than today.

And who said that life needed to kick-start?

All life exists because of….all other life that exists. Everything makes sense as just complex organic biochemistry. Just consider life as a whole single system.
We are deluded that self-organization, self-replication, creating order from disorder, fine tuning exist, because of our perspective bias from being embedded inside the system, that makes us want to separate life into biological units.

rrwillsj
2.9 / 5 (7) Dec 19, 2018
Another poorly written clickbait headline.
Are there no adults with scientific knowledge available to edit these travesties before posting to pop-science sites?
wduckss
1 / 5 (2) Dec 19, 2018
Very scientific research and thinking.
Life today is solely on asteroids (sometimes comets). It is logical that the source of life comes from the asteroid, when there is no life anywhere elsewhere in the near universe.
Bravo smart researchers.
https://www.svemi...html#21b "The originator of life passed near Mars?
Surveillance_Egg_Unit
2 / 5 (4) Dec 19, 2018
Basic ingredients from meteors, asteroids, comets, space debris - dust and gases - even from solar flares possibly. The Solar System is a veritable warehouse of key ingredients for the making of planets, comets, asteroids, etc. plus key ingredients for creating of Life. Humans are so lucky.
Bongstar420
2 / 5 (2) Dec 19, 2018
If a giant comet or asteroid hit the Earth near water, it would leave hot springs for quite some time given the crust was not very thick where it hit. It seems Carbonacious asteroids are probably integral for the soup.
Old_C_Code
1 / 5 (1) Dec 20, 2018
hit the Earth near water, it would leave hot springs for quite some time


Take another bong hit, your fiction is almost sensible.
torbjorn_b_g_larsson
not rated yet Dec 20, 2018
There were plenty of sources for organics on early Earth, and impactors - either directly or by causing hydrothermal systems as Bongstar mentions - were one large if not sole source. And of course if key biochemicals were sourced that way they could have been part of the environment that went into the evolution of life.

However of DNA sugars were produced it would point *away* from impact sources being crucial for that - in modern cells - key molecule, since DNA both genetically and metabolically was a later adoption of cells. The use of RNA, which has a less robust sugar, evolved before it (since the core of the shared genetic machinery is RNA and not DNA, and DNA nucleotides are modified from RNA precursors metabolically).
Sahstar
3 / 5 (1) Dec 23, 2018
And who said that life needed to kick-start? All life exists because of…all other life that exists. Everything makes sense as just complex organic biochemistry. Just consider life as a whole single system.

@heyheybo You do not make any sense. You require no more than common sense to know that life *had* to start at some point on Earth since initially it was nothing more than a magma-hot sterile rock, before that a collection of smaller rocks which coalesced into one, and even before that there was nothing. So what's the point of your tautology?

Now, your other points (self-organization, self-replication, order from disorder etc) are effectively about the systemic thinking or approach (systems & complexity theory, emergence etc) in science. These have absolutely nothing to do with "separating life into biological units". That is the reductionist approach, which is the complete opposite of them. On the contrary, they *do* tend to consider life as a "whole single system".
torbjorn_b_g_larsson
5 / 5 (1) Dec 25, 2018
You require no more than common sense to know that life *had* to start at some point on Earth since initially it was nothing more than a magma-hot sterile rock,


Not even common sense (which has a terrible track record in science when we start exploring uncommon outcomes or systems), it is an observation based on the proxy observations that early Earth was uninhabitable and now it is habitable and inhabited. Since 2016 it is suspected - based on best available observation - that the last common universal ancestor was still half alive, not able to live outside the vent geology that it had diverged from.

In retrospect the emergence seems unremarkable (no problematic transition) and easy (happened early).
morbas
not rated yet Dec 27, 2018
And no where Panspermia Theory,
NOVA Life's Rocky Start posits signal of life soon after water found pre-400Ma after Earth formation. Ocean rift thermal vents represent an obvious path of deep strata microbial life into the deep sea biosphere. The existence of microbial life in deep nutrient barren rock beg recognition of interstellar Panspermia residue from other worlds. With larger windows of time, is that the chemistry of life source? Is Rare Earth the sole harbinger of Terrestrial Intelligence?

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