Tag Archives: history of Earth

On Space Cattle and Looking for the Origin of Life

Or, A Little Mars &  Origins of Life History (and other related thoughts) Before Tackling Today’s Space Exploration Debates, Part IV

Space Cattle Image
Space Cattle Mash-up by Terry Bailey

Okay, so a couple of posts ago we left Stanley Miller and Harold Urey at the University of Chicago, in 1952, trying to create chemical reactions that would simulate Jupiter’s atmosphere. They were doing this because it was thought that Jupiter’s current atmosphere might closely resemble the atmosphere on early Earth. And the reason they wanted to simulate Earth in its early days was so they might see what conditions were present that led to the emergence of life.

The goal here, remember, was to figure out the origin of life. What kind of environment would be required for life to begin, and what might “spark” life.

Miller and Urey took molecules known to be present in Jupiter’s 1950’s atmosphere and placed them into a closed system. The gas molecules they used were methane (CH4), ammonia (NH3), hydrogen (H2), and water (H2O). Then they ran an electric current through the contained gases, to simulate lightning storms believed to be common in the early days of Earth’s formation. What they had accomplished was to simulate the presumed atmospheric environment of Early Earth. And, remember from our previous discussion with scientist Sherwood Chang, they were looking for some sort of chemical reaction ( a chemical reaction results from something – in this case, gas molecules – reacting with a source of energy – in this case, faked lightening).

So, qué pasó? Well, the scientific journals describe it a bit more scientifically, but I like what Sherwood Chang said to me: “At the end of one week, they fished out what was left in the pot and made the astounding discovery of the presence of amino acids, the building blocks of proteins, and therefore of life!”

At week’s end as much as 10-15% of the carbon was now in the form of organic compounds. Two percent of the carbon had formed some of the amino acids. (source duke.edu) And, also according to Chang, “Three or four of the amino acids they found – in the pot – were the very specific amino acids that all biology uses. Out of a potentially almost limitless number of amino acids that are theoretically possible.   Most importantly, The Miller-Urey experiment showed that organic compounds such as amino acids could be made easily under the conditions that scientists believed to be present on  Early Earth.

Today most of us don’t realize how big this was. Not just that the scientists “created” the building blocks of life but that they had been able to study something so successfully in a laboratory using a technique of simulation. We take simulations for granted today. But in the 1950s this was huge. And the Miller-Urey experiment resulted in an avalanche of such experiments by other scientists. Simulations of the Early Land, the Early Oceans, the ability of of volcanic events (stuff + energy) or sunlight (energy) and other “stuff” to create organic matter (life), on an on.

As ideas changed about what the Early Earth atmosphere actually consisted of, the simulation ingredients changed. But, eventually these Early Earth chemists managed to produce all the biological amino acids, and lots of other amino acids that are not used in biology.

Scientists at first became very optimistic that they were on the cusp of actually discovering and understanding the origin of life on Earth. In the 1950s many thought that they would have the question of life’s origins wrapped up in a couple of decades. But, in fact, their journey was just beginning.

One of the many interesting things that Sherwood Chang shared with me during our drive between Berkeley and Vallejo came in response to my questioning him about how much he follows scientific progress now that he has turned in his Ames Laboratory garb for a cowboy hat in order to roam and manage his cattle ranch in Northern California.

Sherwood patiently addressed my perhaps over the top enthusiasm about the recent Mars mission and space exploration in general. He explained that a big aha moment for him was the realization of how slow research is. How many years go by, and how little we really learn in each chunk of time. Sherwood played his role in the timeline of human exploration and discovery. Now he is doing something else, cattle ranching. The scientific exploration continues, but the pace is  slow and will always be so. It took me a while to “get” what Sherwood was telling me about this.

My aha moment came when I began to read about the controversies that have followed the life creation simulation phase of those enthusiastic 1950s and 1960s scientists. For since that time, controversies have sprung up about the validity of their experiments, and many more, alternate, ideas have been proposed as to how those early amino acid building blocks of life might have “emerged” on Earth. Research takes time. Sometimes results and discoveries are validated, and sometimes they are invalidated – both the validating and the invalidating  taking years and years. Sometimes results and discoveries force the asking of many more new questions, the turning in new directions, which, in turn, takes more time. What seems to us in the moment some “great” discovery is usually just a pinpoint on the continuum of exploration – a continuum that will last as long as we do!

So, hats off to Sherwood for the role he played in the search for life on Earth, and happy trails to him on his Northern California ranch.

Next we will look at some of the controversies that succeeded the 1950s and 1960s simulator explorers, and start looking about the theories and research that has followed them. . . .

 

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How Sixto Rodriguez’s Searching for Sugarman Led Me To an Amazing Personal Lecture by a Space Scientist About the Search for Life

Or, A Little Mars &  Origins of Life History Before Tackling Today’s Space Exploration Debates, Part I

picture of Stanley Miller, Harold Urey and Sixto Rodriguez
Stanley Miller, Harold Urey and Sixto Rodriguez

In my post before last I mentioned I’d share some Mars exploration history before moving on to Mars in current events.

In the midst of my interest in the current state of space exploration I coincidentally was offered a ride by a space scientist between my friend Karen’s apartment in Berkeley and my friend Joe’s house in Vallejo last October. I was visiting the Bay Area in order to see and hear the amazing Sixto Rodriguez, who was appearing at Bimbo’s 365 Club in San Francisco.

I’d discovered Sixto was soon to play in San Francisco (my home town) after I saw the documentary about his remarkable life, Searching for Sugarman, in Pasadena. I went home, jumped online, and, in a happy spontaneous act, bought several tickets for his performance. I then called a few friends in the Bay Area to tell them I was coming up for a week visit, and asked them all to join me for the concert. Karen had insisted that I not bother renting a car as I could take BART or hitch rides any where I wanted to go. I saw this as a real adventure, and was later glad I took her advice. One experiences a whole new social world without the “protection and safety” of one’s own vehicle.

Sherwood Chang, the scientist who gave me the lift to Vallejo,  is a retired space scientist now living in Northern California and running the largest organic cattle ranch in the state. He spent his previous career as a scientist with NASA ‘s Ames Laboratory in Northern California. I know that scientists David Peat and David Bohm would not have been surprised by what I considered a very happy coincidence (to meet a space scientist on vacation when I am blogging about space), because Peat and Bohm noted that it is of greater interest that we all do not notice more life coincidences given the mathematical likelihood of their abundance.

I hopped into Sherwood’s SUV, buckled up, turned on my GPS as neither of us knew how to get to Joe’s from Karen’s, and asked him, “So. Tell me about your career as a scientist.” He questioned what I wanted to know, and I told him, “Everything.” I also told him that I have read lots of science since I was a very young kid, even though I am professionally a writer and artist, so that he did not have to talk down to me. Sherwood took me at my word, and proceeded to thoroughly entertain me with the most elaborate and compact one hour lecture (about the history of the search for life in space exploration ) I have ever experienced.

This is what I learned:

One way we can begin to understand the history of our universe biosphere is by studying molecular biology. Because the history of living things is stored in the genetic code of all organisms. But if we want a full understanding, we must also glean information from a bunch of other scientific disciplines. Astrophysicists look deep into space, and back in time, and try to figure out how planets formed around stars. Geochemists and Geophysicists help us to understand how planets formed  and what the environment is/was like in each of the star systems planets they study. They are all wondering if and when any planets or planetary systems are/were receptive to life or not.

While these scientists are doing their research, mathematicians and computer scientists are busy analyzing the data these  scientists come up with, and developing theories based on that data. One can certainly imagine that we are able to understand a great deal more today with the powerful computers at everyone’s disposal for modeling, calculating and analyzing, than we were able to understand when all we had was a roomful of mathematicians sitting around calculating on their own (as recently as WWII to my knowledge) or working with a room-sized computer that had about 100K of memory!

Sherwood began his career in the 1950s as a chemist. Chemists study reactions. And the reactions Sherwood and his buddies were interested in were those that occurred in ancient, primordial, environments on Earth and on other planets in our solar system. If we are going to understand the beginning(s) of life, a great place to start is on the young Earth at the time our planets formed. And the first thing we would need to know, is what was the environment like then, before life appeared. Of course the goal then was to understand when and why life appeared here on Earth, and if it did on other planets as well.

Back in the day (as my college design students are fond of saying) not much was known about primordial (earliest stage of development) environments. Many scientists thought that the early atmosphere of Earth was similar to that of Jupiter. That belief was based on actual science according to my space history travel guide, Sherwood; it was just that Jupiter’s was the only atmosphere they thought relevant to early Earth’s.

So in 1952 at the University of Chicago, two scientists, Stanley Miller and Harold Urey, decided to create chemical reactions that would simulate Jupiter’s atmosphere . . . to be continued

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