Life manufactured in space

November 26, 2010 | By | 5 Replies More

Every once in a while, I would read an article that claimed that life originated somewhere else and then came to earth on an asteroid. This claim puzzled me, because it sounded like an eternal regress. If life began on some other planet and then came to earth, how did it originally develop on that other planet? It turns out that I misunderstood the claim, and I have been set straight by a recent article called “Cosmic Blueprint of Life,” by Andrew Grant, published in the November 2010 edition of Discover Magazine (this particular article is not yet available on the Internet).

The claim is not that life developed on some other planet and then eventually came to earth on asteroid. Rather, the claim is that many of the basic chemicals necessary for life were manufactured in space, and then showered upon earth (and presumably other planets where–presumably–life exists). In this article, Grant writes that:

[The notion that the] underlying chemistry of life could have begun in the far reaches of space, long before our planet even existed, used to be controversial, even comical. No longer. Recent observations show that nebulas throughout our galaxy are bursting with prebiotic molecules. Laboratory simulations demonstrate how intricate molecular reactions can occur efficiently even under exceedingly cold, dry, near vacuum conditions. Most persuasively, we know for sure that organic chemicals from space could have landed on Earth in the past–because they are doing so right now. Detailed analysis of a meteorite that landed in Australia reveals that it is chock-full of prebiotic molecules. Similar meteorites and comets would have blanketed earth with organic chemicals from the time it was born about 4.5 billion years ago until the era when life appeared, a few hundred million years later. Maybe this is how Earth became a living world.

According to Grant, there’s two ways to look at the famous 1953 experiment by Stanley Miller and Harold Urey. They prepared a closed environment with the gases they assumed constituted the early Earth atmosphere (methane, ammonia, hydrogen and water). They then simulated lightning strikes through the use of electric sparks. Within a week, the process had produced a variety of prebiotic compounds. As Grant points out, however, the experiment did not show that “all the building blocks of life could have emerged on Earth from non-biological reactions.”

Even the simplest lifeforms incorporate two amazingly complex types of organic molecules: proteins and nucleic acids. Proteins perform the basic task of metabolism. Nucleic acids (specifically RNA and DNA) encode genetic information and pass it along from one generation to the next. Although the Miller-Urey experiment produce amino acids, the fundamental units of proteins, it never came close to manufacturing nuclear bases, the molecular building blocks of DNA and RNA.

Grant points out that space was long considered to cold and too low-density to form molecules, but this has now been disproved. Scientists have now found ammonia molecules near the center of the Milky Way using a radiotelescope. They have also found formaldehyde, formic acid and methanol. Laboratory simulations of the environment of outer space had produced “dozens of prebiotic molecules, among them the same amino acids that Miller and Urey found.” Further, these experiments have produced “intricate molecular rings containing carbon, nitrogen and hydrogen: fatty acid like molecules that look and behave like the membranes protecting living cells; and nucleic acids or nucleotides, the primary components of RNA and DNA.

Orion Nebula - NASA

Even if these substances are produced in space, one still needs to explain how they reached Earth (and other planets). Scientists now believe that some of this material remains nearly intact in the comets and asteroids which have collided with the Earth. Consider that a 200-pound meteorite struck Murchison Australia in 1969.

Analysis indicates that the rock contains millions of organic compounds, including amino acids that could not have come from terrestrial contamination. Two years later, Sita Martens from Leiden showed that the meteorite contains nuclear bases. David Diemer of the University of California, Santa Cruz, even found a fatty acid like molecules similar to those [created in the lab].

Scientists have found rocks from Mars and the moon “all right here on earth.”

A new experiment that begins with the organic molecules found in the atmosphere of Titan (one of Saturn’s moons) pushed the envelope even further: They ended up with all of the nuclear bases that make up RNA and DNA. The study suggests that life’s chemistry could have begun on earth, in space, or on the surface of a planet (or moon).

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Category: Astronomy, nature, Science

About the Author ()

Erich Vieth is an attorney focusing on consumer law litigation and appellate practice. He is also a working musician and a writer, having founded Dangerous Intersection in 2006. Erich lives in the Shaw Neighborhood of St. Louis, Missouri, where he lives half-time with his two extraordinary daughters.

Comments (5)

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  1. Rich Paxson says:

    Great distinction! Life chemicals were maufactured in space and then showered on earth; as opposed to life itself migrating to earth from outer space.

    Stephen Hawking writes about the manufacture of life chemicals in his new book, The Grand Design(2010). In Chapter 7: "The Apparent Miracle" Hawking discusses the requirements first for creating carbon atoms, and then for those atoms to form human beings. Paraphrasing Hawking, carbon is formed inside the core of a collapsed star at temperatures of about 100 million degrees Kelvin. Quoting Hawking now:

    "But that carbon [in the core of the collapsed star] is still a long may from forming ordered aggregates of chemical compounds of the type that can enjoy a glass of Bordeaux, juggle flaming bowling pins, or ask questions about the universe. For beings such as humans to exist, the carbon must be moved from inside the star to friendlier neighborhoods. That, as we've said, is accomplished when the star, at the end of its life cycle, explodes as a supernova, expelling carbon and other heavy elements that later condense into a planet."

    I've read "The Grand Design" once, and need to read it more than once again. Not only does Hawking explain incredibly complex subjects with great clarity, but also he has a wonderful sense of humor to boot!

    At least that's the humble opinion of this "aggregate of chemical compounds," who while not quite able to "juggle flaming bowling pins" does indeed enjoy an occasional glass of "glass of Bordeaux" and "asking questions about the universe."

  2. Ben says:

    NASA's secret is finally out: Researchers say they've forced microbes from a gnarly California lake to become arsenic-gobbling aliens. It may not be as thrilling as discovering life on Titan, but the claim is so radical that some chemists aren't yet ready to believe it.

    Wolfe-Simon theorized that some organisms could have evolved in ancient times to make use of arsenic-based compounds known as arsenates, in place of the phosphates used by virtually all the organisms we know today. Such arsenophiles might even persist in environments with unusually high levels of arsenic — environments such as the hydrothermal vents at the bottom of the ocean, or Mono Lake in California.

    http://cosmiclog.msnbc.msn.com/_news/2010/12/02/5

  3. Ambrose Mnemopolous says:

    These curious things do happen.

    http://www.technologyreview.com/blog/arxiv/25699/

    You might also like this:

    http://home.fnal.gov/~annis/silence.ps

    Things are moving along on schedule.

  4. Star Larvae says:

    The Discover article and commentary here display the timidity typical of people who follow these developments. Why o why do we cling to the idea that the first cell must have been assembled on Earth? There’s this funny assumption that organic chemistry in space can grow in complexity but not become so complex that viruses and bacteria result. The final assembly must occur on our humble planet. This is nonsense. Conditions in interstellar space are more conducive to biogenesis than is the surface of a planet. The case is made here:

    http://www.starlarvae.org/Star_Larvae_Silicon_and_Biogenesis.html

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