Tag Archives: astrophysics

Recurrent Dreams of Life in Meteorites

Meteorite in Aurora

This stunningly beautiful image of a meteorite falling through aurora borealis was taken at Patricia Beach, Manitoba by photographer Shannon Bileski of Signature Exposures in March 2013       and is used with her kind permission.

Humans have probably been looking for signs of life from the stars since we first looked up. The first claim for life in meteorites was for a meteorite that fell in 1682. The most famous claim is based on an examination of a carbonaceous chondrite meteorite that fell in Orgueil, France in 1864. There a no less than 440 papers on that meteorite alone. All told there have been eight rounds of claims of discovery of life in meteorites including the Orgueil one.

There are two approaches to deciding if life is in a meteorite: morphology and chemistry. When considering the possibility of morphological evidence in meteorites the friability, salinity, and porosity of the meteorite samples has to be considered. One problem is that primitive life consists of single cells, sometimes strung in filaments or in clusters. It is hard to tell a “real” fossil of such life from an inorganic growth or precipitate.

Some chemicals have been presumed to be unique to life. However, the development of organic chemistry soon showed it was possible to create organic compounds (including those found in meteorites) in the laboratory. Now we know that many of them abound in interstellar space. Therefore, organic compounds alone are no longer considered sufficient proof of life.

Another problem is that life is everywhere on Earth. Examining a meteorite found on the Earth means that if you do find life, it is far more likely to be contamination from life we already have here than any sort of novel panspermia sample. It has been argued that if a possible microfossil were found on the interior of a meteorite it could not be the result of contamination. However, a huge taxonomic diversity of prokaryotes colonized the Tatahouine meteorite in less than 70 years making such claims dubious. And when a meteorite lands on earth it comes from a vacuum and so will suck in air into its interior upon entry and cooling. Carbonaceous chondrites, the most likely kind of meteorite to contain life from space, are hygroscopic, i.e., drawing into them any moisture in the vicinity. And so it is possible for some eager microorganism to be drawn into or crawl into the interior of the meteorite. It is far more reasonable to assume that motile microorganisms, perhaps from spores in the air falling on the surface, invaded museum specimens at times of high humidity and subsequently fossilized. We give an example in Embryogenesis Explained of hot springs bacteria that get fossilized in 2 days. Earth rocks often contain live bacteria deep inside. Similarly, organic chemicals can seep into rocks and meteorites. It can even be assumed that anything that got close to Earth might get contaminated since Earth life, like diatoms, have been claimed to be found floating about on the outer reaches of our planet’s atmosphere. Since the 1960s, if a meteorite fell through our atmosphere, then any life found on or in it can be safely presumed to be Earth life contamination.

And then there are hoaxes. Dick was involved as an undergraduate in a 100-year reexamination of the Orgueil meteorite. Ed Anders and he uncovered a hoax in which some unknown person placed a piece of coal and the dried bud of a local plant into a sample of the meteorite. Dick showed, by analyzing it for the amino acid hydroxyproline, that the mass had been put back together with animal glue. The hoaxster placed the specimen on the local museum shelf, where it sat 100 years. They probably didn’t live to see their crafty work found, but it did make scientists extremely wary a century later.

We therefore agree with the decision of NASA to keep Rover far away from the place where NASA seems they have found water. No matter how carefully NASA cleaned up Rover before sending it off, there is always the possibility one of our more persistent and clever forms of Earth life hopped a ride and would immediately start colonizing the Red planet’s water. That would not only be bad science, it might also be a violation of the Prime Directive.

You can read the full article on this topic with references and additional information at: Recurrent Dreams of Life in Meteorites by Richard Gordon and Jesse C. McNichol (2012), a chapter in Genesis – In The Beginning Volume 22 of the series Cellular Origin, Life in Extreme Habitats and Astrobiology. Or ask Dick for a reprint: DickGordonCan@gmail.com

If you would like a hard copy of the gorgeous picture of the meteorite against the aurora, you can purchase it by contacting Signature Exposures.

Could there have been a single origin of life in a big bang universe?

Abell 2218 HST WFPC2 I, V, B

Hubble Telescope Image, one of the best ever views of the massive galaxy cluster Abell

Excerpt from our book Embryogenesis Explained:

We define embryogenesis as the ability to produce the right kind of new cell, in the right place at the right time. This phrase “the right cell, in the right place, at the right time” is an expression due to Hans Driesch around 1890. All other aspects of embryology like morphogenesis, differentiation, and regeneration arise from embryogenesis of a first simplest proto-life form. Where and how did this first life originate?

There is a delightful scene from the Star Trek Next Generation television series where a powerful, immortal being, Q, takes Captain Jean Luc Picard back in time and space to stand looking down at a tiny pool on a hostile volcanic planet. Q tells Picard this is Earth eons ago and Picard should look in the pool. Q then laughs. Q says that THE miracle is about to occur. Right there in that puddle, Picard’s far distant first ancestor is about to come into existence. Q comments that humans are the mere product of a pond of goo. In their ongoing debate about the merit of humans Picard quotes Shakespeare saying:

“I know Hamlet. And what he might say with irony I say with conviction. ‘What a piece of work is man! How noble in reason! How infinite in faculty! In form, in moving, how express and admirable. In action, how like an angel. In apprehension, how like a god…’”.

Our God-like form is assumed to have begun in a primordial soup from some primitive bit of RNA (or proteins) that was able to self-replicate. There are many hypotheses about the conditions that allowed first life to form and attempts to simulate the event by chemistry or computer. The two most common are that this remarkable feat was accomplished while inside the simplest of membranes in a pool of water or near a hot hydrothermal vent.

Our universe started with the Big Bang 13.75 billion years ago. It started hot and cooled down, forming galaxies and stars and perhaps planets as early as 200 million years after the Big Bang. Our records of life on Earth begin a mere 3.8 billion years ago with what looks like prokaryotes in fossils and the unique chemical signatures of life. While prokaryotes are simple compared to us, they are organisms that have evolved to levels of complexity far beyond the proto-life forms scientists envision at the origin of life. So where did life begin? Did first life start here on Earth at some time before 3.8 billion years? Did it begin somewhere else and then transported here? As mankind gets ready to travel beyond our moon this is becoming a more urgent question and more hypotheses have been brought forward to try to answer it.

If life started elsewhere in our turbulent Milky Way galaxy and traveled to Earth, this increases the possible environments that life may have started in. It also increases the time total available for life to have evolved to form those first recorded prokaryotes. If life formed on earth then the maximum time is sometime after the 4.8 billion years since Earth started. If life started elsewhere and traveled here, then the time is stretched to a maximum of about 13.55 billion years ago. We eukaryotes are far more complex than our prokaryotic ancestors. Humanity arose from our prokaryotic ancestors in a mere 3.8 billion years. This means, if life began beyond Earth, then complex intelligent beings like us could have arisen in our universe as soon as 9 billion years ago, well before Earth even formed.

Maybe life on Earth started with nothing more complicated than prokaryotes because it took 9 billion years for life to evolve that far. Extrapolated data suggests this might have been the case. If that idea holds up, then life indeed did not originate on earth but life did find the right conditions for the first evolution of complexity beyond prokaryotes to produce us here on this obscure little blue planet. In our own galaxy there may be 15 to 30 billion habitable planets and even more exomoons that are habitable. If that is true then the prokaryotes that arrived here on Earth may have also been deposited on other suitable planets as well and may have been evolving along at the same pace as us. Perhaps we are not alone and all complex life like us is approximately the same age as we are.

The universe is expanding much faster than primitive life could have travelled about in space, borne on the winds of supernovae explosions, hypervelocity stars, galactic ejecta, or transferred during frequent galaxy collisions. Whole “rogue” planets are occasionally ejected from their solar systems and bounced out and sometimes towards capture by other stars like celestial billiard balls. Taking into account all of these phenomena, we can estimate that the “speed of life” without technological assistance is limited to 1000 kilometers per second. This is 1/300th of the speed of light, which is 300,000 kilometers per second (299.792458 kilometers per second in vacuum, to be more precise). Despite the vast distances in space, there are many means for life to get around, even between galaxies. But life can only get so far.

Making the generous assumption that life is somewhat evenly distributed across the universe, Dick, writing with Richard Hoover, calculated that life must have started independently at least 50,000 times, if not many more. New results suggest that the speed of life could approach the speed of light, as may happen with stars and their solar systems flung out of colliding galaxies by close encounters with the pair of their black holes, possibly carrying along their inhabited planets. Even then there would still have to have been 170 independent starts to life, to fill our universe.

If we assume first life began here on earth and did not arrive from elsewhere, then the organic molecules required for life to start must be from somewhere. There is more than one hypothesis about that. Perhaps organic molecules were made fresh here on Earth from nothing more than simple gases by fierce activity of lightning and/or volcanoes. Perhaps they were delivered by crashing comets or meteorites on our young planet before it had an atmosphere. Our galaxy is certainly rich in organic molecules we know are synthesized around stars.

The religious among us who nonetheless embrace the overwhelming evidence for evolution often see the finger of God as stirring that primordial goo: yes, life did start out as goo somewhere in the universe, maybe more than once, but it could only have done so because God did it. With 170 to 50,000 plus start ups, we could suggest that He’s still busy doing it. As none of us have a Q to take us back to the very first primordial goo, these questions may never be satisfactorily resolved. The best we can aim for now is a re-creation “from scratch” of something we would call life. And if one must invoke God, then we can at the very least, expect to figure out exactly how He does it.

Finis

Could there have been a single origin of life in a big bang universe? No, unless we accept that only our remote corner of the universe has life. If life exists throughout the universe, as in the vision of Roddenberry’s Star Trek universe, then there must have been multiple origins of life. But we have yet to discover any real evidence that there is life beyond our planet. Stay tuned.

Read about The Speed of Life. The speed of life as postulated in Gordon&Hoover may be an underestimate. We previously reviewed From the First Star to Milkomeda where a star doing a slingshot around two black holes in colliding galaxies could increase the speed of life to near the speed of light, assuming anything on its planets could survive such a ride.

(Ultimately) Alone in the Universe, by Richard (Dick) Gordon

Loeb2015

I was trying to convince Abraham (Avi) Loeb to join me as an editor of Habitability of the Universe before Earth (HUBE), a book I’m planning in the new book series Astrobiology: Exploring Life on Earth and Beyond (World Scientific Publishing, London) with series editors Joseph Seckbach (Israel), Pabulo Henrique Rampelotto (Brazil) and me (Canada & USA). Now, as Natalie and I have long observed, organizing scientists is much like herding cats. Avi turned me down, despite saying he is very drawn to the subject, on the basis that he is writing yet another book (Books by Abraham Loeb) and that he is heading some sort of award giving group (Breakthrough Initiatives Project of the Breakthrough Prize Foundation). Then he sent me his latest book, available only in Kindle format, From the First Star to Milkomeda. (He did not ask me to do this review.) Milkomeda refers to the result of collision of our Milky Way Galaxy with the “nearby” Andromeda Galaxy “within a few billion years”. Whew! Imagine trying to absorb and assimilate migrants from another 100 billion planets.

This is a semi-autobiographical account of a fine mature scientist and academic who has reached the peak in his career. By reading this book you can see how his mind works and sense his high personal and academic standards. You can also sense the intense loneliness that comes with reaching such a place. It’s a weird book giving you a view most people never see, the workings of an imaginative, clever, sharp, yet careful mind. He is a theoretician, par excellence, with substantial immunity from the grant system and the committees who decide who gets viewing time on expensive, communal telescopes. As a theoretical biologist I understand this independence. It allows our ideas to pour forth.

Avi thinks big. His latest work is on the earliest formation of water in our universe, and the possibility that life developed way back when. I have long been annoyed with the many books on the origin of life that presume, without discussion, that life began on Earth. This is one of the last anthropocentrisms, the first being that Earth is the center of the universe. I had an opportunity to knock the idea down a bit when Alexei Sharov and I wrote Life Before Earth. He came at the problem from a biological point of view, extrapolating a measure of organism complexity back in time, and I helped spell out the consequences. Avi calculates the first time the universe had places warm and cool enough to support liquid water. Both calculations allow for life for most of the 13.6 billion years our universe has been around, not just the paltry 4.54 billion years since the formation of our solar system.

When you start Milkomeda, you think you are about to be treated to a proper autobiography, farm boy near Tel Aviv rocketing to theoretical astrophysicist. But the book in short order plunges into the kind of language one expects in grant applications, giving only hints of Avi’s personal life. As all of Avi’s work is new to me, his 500 or so papers not having crossed my computer desktop previously, I saw past the “justifications” in the grant style of writing to fascinating ideas, like stars doing sling shots around pairs of black holes to achieve speeds near the speed of light. What a ride! Now I have to know whether life on planets around such flying stars would have any chance of surviving the trip? If so, we’d have a mechanism that could spread life well beyond the confines of galaxies. Close encounters with black holes are tales worth telling. I really enjoyed this.

Avi has reached that point in scientific life where he gives much thought to mentoring. A substantial portion of Milkomeda is devoted to the cultivation of the minds of young astrophysicists, trying to strike a balance between them towing the line and being obnoxiously creative. Here Avi shows he is one of us unherded cats. Did you ever hear of a labor union of scientists? No such thing. I’m still nominally President of CARRF, the Canadian Association for Responsible Research Funding, whose members have long since dispersed or departed Earth. My cofounders rejected my preferred moniker UNFUN, the Union of Unfunded Scientists. But under the CARRF banner, we produced much peer reviewed and other literature on how to improve/replace the peer review system for grants. Avi has rediscovered many of these ideas, our tiltings at windmills, unaware of our published efforts. So many scientists independently come to these conclusions, but ununionized, nothing happens. The shame of it all is that the taxpayer, who foots most of the bill for scientific discovery, gets far less bang for the buck than should be possible. I so completely agree with him but I found the whole topic maddening to read about, again. He gives ten specific examples in astrophysics of scientists suppressing the research of other scientists they thought were wrong. It is a warning for anyone who practices science by consensus. If you are someone who has looked with curiosity at the inner workings of astrophysics and wondered what being in the field is about, this book will give you keen insights.

Good ole Lord Kelvin predicted the Heat Death of the Universe, back before nuclear energy was discovered, a rather depressing scenario. Avi, while holding his head high in contemplating the universe on the cover of Milkomeda, points out that with the universe expanding, most of the galaxies we see beyond our local cluster will vanish from the sky. Their light will not reach us, because the rate of expansion of the universe exceeds the speed of light. Somehow gravity will keep our small corner of the universe intact, but alone. Well, perhaps: another depressing outcome. But maybe we could hitch a ride around that pair of black holes from the Milky Way and Andromeda as they hurl towards each other, and be out of here. Stay tuned. And buy the book. You still have time.