Field of Science

Examples of good astrobiology please

The comments on my short post about whether my original criticism of the Wolfe-Simon paper was too 'personal' bring up the issue of whether 'astrobiology' is a genuine research field, or just a catchy title applied to conventional biology funded by NASA's astrobiology program.  Because the only papers from this program that come to my mind are seriously flawed*,  I want to raise a related question - what good science has this program produced? 

I know of excellent biologists funded by NASA, so I'm sure there are good papers out there.  I guess I'm wondering whether there's an inverse relationship between a paper's quality and its claims of astrobiological relevance.

Here are the bad papers I'm thinking of:
1.  The Mars meteorite paper (1996):  Here's a more even-handed evaluation than I would give it.

2.  This nanobacteria paper (2005):  I haven't posted about it, but the structures called 'nanobacteria' appear to be just aggregations of calcium salts.  I don't think any reputable microbiologist believes that they are bacteria.  Here's a critical review from PNAS.

3.  The Salmonella in microgravity paper (2007): See this post for my evaluation.

4.  The arsenic-DNA paper (2010): See this post for my evaluation.

5.  The fossil bacteria in a meteorite paper (2011): See this post for my evaluation.
So, commentors, please point me to good astrobiology papers. 

Just to clarify (after reading the comments so far):  What I'm looking for is papers that report competent experimental research and that self-identify as 'astrobiology'.

* Yes, I know that my memory of astrobiology papers is no doubt flawed because only the bad ones stick in my mind.  That's why I'm asking.


  1. I think the better astrobiology papers are of a more theoretical nature than the papers you mentioned. Your list of papers mainly features incredulous claims and few deliberations on the nature of life (both on earth as elsewhere).

    I quite like the McKay paper in plos biology a few years ago, in which he describes the biochemical selectivity of life (the 'lego principle').

    I wrote about that paper here last week:

  2. NotAnAstrobiologistMay 30, 2011 at 9:28 AM

    A bit of a diversion to Rosie's question, but here is a post that I found very interesting.

    The author (apparently a self professed exoplanetologist) used google Ngram to show the relationship between the published occurrences of "exoplanetology", "astrobiology" and the number of exoplanets discovered that year.

    He provides a very interesting take on why "astrobiology" (which doesn't really exist before 1992) seems to have over taken "exobiology". I think he is saying that "astro" is bigger than "exo" which is why

    "[astrobiology] locked on as the bastion to the science of "Life elsewhere in the universe""

    The discovery of exoplanets is one of the most profound of all time. As observation techniques are refined, I think many people are expecting to discover some amazing things; perhaps some will be filed under the "astrobiology" heading.

  3. Really, Dr. Redfield?

    This is about as silly as asking if there are any good papers that have ever been published in electrochemistry, and then saying "the only one I remember" is Fleishmann and Pons.

    I think a short lesson in the breadth of astrobiology is in order. For that you can go here:

    If you want to see what the "roadmap" is for astrobiology, you can go here:

    As to publications, I'm sure you can find a lot here:

    ... or here:

    ... or here:

    ... and while not being "exclusively" astrobiology, many astrobiology papers are also published here:

    The NAI has a links to lists of publications here:

    You can also view the portfolio of current astrobiology research at NASA here:
    (Note there are four programs on the top there, and the research extends well beyond the NAI.)

    Really. This is silly.

  4. NotAnAstrobiologistMay 30, 2011 at 10:40 AM

    Yikes Shawn, I think Rosie is implying something like "noteworthy and insightful" when she writes "good science"; she gives examples which seem to make sense and gives an idea what she is looking for.

    Your comparison to "electrochemistry" isn't really fair. People have been calling themselves electrochemists far longer than they have been calling themselves astrobiologists. I think Rosie is asking (in a fairly honest tone) what you'd point from astrobiology to say "See? This is cool, and this is astrobiology!".

    A link dump that includes a LMGTFY doesn't really help. I'm sure that most of the paper stores you point to contain mostly garbage research (as this would be true for any field of study), pick out some gems for us and tell us why they are great. Hopefully they might counter some of the higher profile papers that Rosie and others think of as "bad" papers.

  5. NAA,

    The field of astrobiology has been synonymous and has grown out of what was originally the exobiology program at NASA. People have been researching this field one way or another for at least 50 years. It is a large enough research area where there are textbooks, primers, roadmaps, and an international research effort. It was also extremely prominent in both the astrophysics and planetary sciences decadal surveys. Keep in mind that these were documents created by the National Academy of Sciences, and are meant to represent a survey of future research directions that are warranted in these areas.

    There is even have a "best of" list from the last 50 years of research in the field; a list that includes the ALH84001 claims... and the follow-up research from the AB community:

    NAA, if you look at that list and track down publications related to it I'm sure you'll find some gems. You read as a very intelligent scientist capable of following up on this on your own.

  6. ... and this is just the issue. When a field is a broad and well-populated as astrobiology has become, it is almost silly to point out a paper or two to say: here, this is THE good paper. There are simply so many that such an effort does not do justice to the breadth of good science in the field. (I also consider it an open invitation to play a game of "moving goalposts," which I am doing my best to decline.)

    Cherry-picking the most controversial work that has arisen from the field does not change the breadth or quality of the rest of its research and results.

  7. @Shawn: I'm not asking for the names of journals that publish astrobiology papers. I'm asking for citations to specific papers which the commentor has read and recommends as good science.

    @NAA: The papers don't have to be particularly noteworthy and insightful, just competent science.

    @Lucas: I'm looking for good experimental work, not just theory and hypothesis.

  8. @Rosie,

    "@Lucas: I'm looking for good experimental work, not just theory and hypothesis."

    Is that to say theory and hypothesis is not good science?

    This is precisely why I refuse to engage in such a request. The goalposts are too easy to move.... and when I sense mobile goalposts, I try not to kick anything through them, although I am sometimes sufficiently bated.

    I gave you plenty of resources through which one can find good science that has arisen from astrobiology research. The references within many of the documents and websites I linked to should be a nice starting point. I do not expect to convince you, but any aspiring astrobiologist reading this would be served well by starting there.

  9. Shawn,

    I think Rosie's request for experimental work is because this is all in the context of the GFAJ work. I didn't take it as a shot against theoretical astrobiology research or the field in general, and I'm a complete outsider. I'm just bringing this up because you're coming off pretty defensively and I think it's unwarranted.

  10. @NAA (I believe that's still you?),

    Perhaps I am being defensive. But I am faced with a post where someone cherry-picks a few of the most controversial papers from my field, and then asks "is there anything good here?"

    I hope you can understand why that would make one take up a defensive posture.

    I believe I have provided plenty of material through which a truly independent-minded party can find high-quality (and low-quality) astrobiology papers, whether they be experimental, theoretical, or field-related. I'm sure you could do this, as could Dr. Redfield.

    In case you are right that I am overly defensive - and to avoid fanning the flames any further - I am going to exit stage right and go cook some pork chops.

    Happy holidays, Dr. Redfield and Dr? Anonymous!

  11. NotAnAstrobiologistMay 30, 2011 at 11:49 AM

    Previous anon was not me. I agree, this is getting a little long in the tooth.

  12. Origin of life studies could be plausibly called 'astrobiology' studies, and there is a lot of interesting experimental work in that field, for example the discovery of iron/sulfur catalyzed organic reactions at deep sea hot vents, and other chemical routes to amino acids, fatty acids, sugars, glycosylamines (RNA/DNA material) and so on. The famous initial paper here is of course the lighting-induced synthesis experiments conducted by Miller. Astro-biochemistry, maybe?

    It's an interesting question - would an Earth-like watery planet also develop the same basic biochemistry as Earth?

    However, this field has had some major errors too, such as claims of microbial vent life surviving extremely hot conditions, well above the current record of 121C.

  13. Rosie, I am somewhat unclear as to what is encompassed by "astrobiology", both by astrobiologists and by yourself. Obviously, we have not discovered alien life yet. So Astrobiology deals with hypotheses and proof-of-principles, unless you extend the definition. The first are papers such as this which deal with how we might detect alien ("aleternative", "shadow", "non-CHON") life. However, you seem to be looking for experimental, or observation-based papers. Therefore, the proof-of-principle (or proof of possibility) group would be of interest. One recent good example of such would be Jonathan Eisen's "4th Domain" paper. Another would be the four-codon ribosome: or works on alternative amino-acids such as those by Peter Schultz (I doubt Schultz will define himself as an astrobiologist though!)

    Another class of papers are those coming from Astronomy. For example, dealing with planetary habitability. Those range from theoretical (i.e. the famous Drake Equation) to the observational. All dealing with the possible number of habitable planets in the galaxy, our ability to detect such habitability, and what constitutes a life-sustaining planet. One interesting anomaly is the detection of methane on Mars, and the methods being developed to try to distinguish whether this methane is of biological or non-biological origin.

    I think, however, that you are too quick in discounting theoretical papers. In a field such as astrobiology, those make a strong contribution and help pave the way towards asking the proper experimental questions.

    Summary of above: (1) define "astrobiology" and "experiemntal" (doe that include observations?) more clearly (2) don't be so quick to discount theoretical work.

  14. @Iddo: Right now I'm interested in evaluating experimental work that self-identifies as 'astrobiology'. I'm not discounting theoretical work; it's just not what I'm looking for.

    As usual, it's only after I've asked my question that I realize how ambiguous it is. I'll add a clarification to the post.

  15. To meet the "self identify as astrobiology" criterion, is it sufficient that the experiments be funded by NASA astrobiology? If so, a great deal of the best prebiotic chemistry and experimental origin of life research in the US is funded by that program, and by its predecessor NASA exobiology.
    To list labs I'm familiar with, and, full disclosure, have worked in, Jack Szostak and Jerry Joyce are both NASA astrobiology-funded and have a very good reputation. For example:
    Lincoln, TA and Joyce, GF "Self-Sustained Replication of an RNA Enzyme" Science 2009
    Mansy, SS et al "Template-directed synthesis of a genetic polymer in a model protocell" Nature 2008
    Check out the acknowledgements, both were NASA funded.

  16. Dr. Redfield,

    How specific are we talking here? Based on the "bad" work you are citing, you seem to allow analyses of samples as "laboratory" work. Would the follow-up work on ALH84001 suffice? Or are you looking for something more in your area of expertise, so you can be a reasonable arbiter of the "goodness" of the experimental approach?

    Trying to better define what you are looking for here so as to avoid getting caught in a strawman argument... Also please realize I'm a theoretician, and the work I do is about as far afield from what you do as it gets within astrobiology.

  17. ... and what counts as self-identifying as "astrobiology"? Publication in an astrobiology journal? Claim funding from astrobiology sources? Discuss astrobiology in the introduction/conclusions?

  18. Dr. Redfield,

    Could you perhaps find something here you could judge?

    I've given you quite a series of lists of publications for you to browse, both here in my previous posts. Can you find something in one of those lists that you have the expertise to judge? Perhaps a google scholar search with "journal:astrobiology" and some of your preferred keywords would do the trick?

    Doing my best here to give you what you are asking for without walking into a potential strawman trap, or providing you with a paper I have not personally read (and thus am uncomfortable vouching for) because it is too far afield from my own work.

  19. And I apologize if I am being overly defensive.

    I do not know anyone on this thread personally (although perhaps I know the anonymous posters?), and I have had extremely frustrating experiences in the past debating much less important topics (BASEBALL!) on the internet with those I do not have the ability to sit across a table from. That, combined with what appears to be an antagonistic attitude towards my area of research, have me on the defensive.

    Colleagues and I will be posting more about much all of this over at a new blog I've started with colleagues. There are legitimate questions underneath much of the skepticism I have been defensive of: what is astrobiology? who does astrobiology research? what are the implications and perils of doing high-risk research? We'll cover all of this.... eventually. We don't plan to do it all in a weekend, not even a 3-day one. ;-)

    Oh, and please, please, PLEASE do not take me as "speaking for astrobiologist. I'm just an astrobiologist that happens to be speaking.

  20. Since theoretical papers have been discounted (for reasons which are not at all clear to me) from entering this 'challenge', I'm going to suggest the original chemical experiments as done by the Viking Mars explorer.

    This review by Harold Klein on the results and the implications for life on Mars is a nice example:

    Whether it's astrobiology or microbiology, there's good and bad science everywhere.

  21. "What have the Romans (NASA Astrobiology) ever done for us?"

  22. In a 50-year-old field of research so broad and diverse as exo/astrobiology (and increasingly so over time), it is difficult to produce short list of papers representing “good science” in the field. The list necessarily must be long to be representative. I’ll offer here some thoughts on gauging the “good science” output of exo/astrobiology. Meanwhile, to provide some context, I’ve posted a paper reviewing 50 years of exobiology and astrobiology at NASA here:

    Where am I coming from? I’m a social scientist, a research professor with the School of Media and Public Affairs at George Washington University, and a principal investigator with NASA’s astrobiology program, engaged in science communication research.

    One widely accepted gauge of “good science” is evaluations by the U.S. National Research Council. While this is not a comprehensive list, here are some reports that may be of interest (references tend to be listed at the end of each chapter). All are available free from
     An Astrobiology Strategy for the Exploration of Mars (2007)
     Exploring Organic Environments in the Solar System (2007)
     The Limits of Organic Life in Planetary Systems (2007)
     The Astrophysical Context of Life (2005)
     Life in the Universe: An Assessment of United States and International Programs in Astrobiology (2005)
     The Search for Life’s Origins: Progress and Future Directions in Planetary Biology and Chemical Evolution (1990)
     Origin and Evolution of Life – Implications for the Planets: A Scientific Strategy for the 1980s (1979)
     Post-Viking Biological Investigations of Mars (1977)

    The following four papers report on just a few of many important products of research supported by NASA’s exobiology program in the years before NASA expanded its breadth and depth to become astrobiology. (I expect that others, if asked “what good science has come out of exo/astrobiology,” would offer other findings and papers – there are many to choose from):
     Carl Woese and George Fox, Phylogenetic structure of the prokaryotic domain: the primary kingdoms, PNAS Nov. 1, 1977, 74:11, 5088-5090.
     Lynn Margulis, Microbial evolution on the early earth (Hereditary endosymbiotic model of microbial evolution of Precambrian prokaryotic and eukaryotic cells), Chemical evolution and the origin of life; Proceedings of the Third International Conference, Pont-a-Mousson, France, 19-25 Apr. 1970; pp. 480-484.
     Stanley L. Miller, Harold C. Urey, and J. Oro, Origin of organic compounds on the primitive earth and in meteorites, Journal of Molecular Evolution, 1976, 9:1, 59-72.
     John B. Corliss et al, Submarine thermal springs on the Gal├ípagos Rift, Science 16 March 1979, 203: 4385, 1073-1083.

    One could assemble a “top papers in astrobiology” list according to any number of criteria. I’m posting a list of “Key Papers in Astrobiology, 1998-2007” here: (I can’t include it in this comment because of character-count limits.) The list originally was prepared in 2007 as input for a National Research Council study. It roughly tracks with the goals of the "roadmap" for NASA’s Astrobiology Program. It focuses primarily on papers in Science, Nature, PNAS, and annual reviews and does not include papers published in astrobiology journals or other highly specialized publications. The papers on the list are not necessarily the first to report on a particular theory or finding or the most cited. Much, but not all, of the research reported was supported by NASA’s exo/astrobiology program (for example, while research on biosignatures is funded by NASA’s astrobiology program, much of the work in planetary formation and extrasolar planet searching is funded by NASA’s astronomy and astrophysics program).

    Check out the list!

  23. Rosie,

    The National Research Council provided a selection of astrobiology research highlights (accompanied by literature citations) in their 2008 report “Assessment of the NASA Astrobiology Institute (NAI),” the result of a comprehensive review of the NAI 10 years after its formation. The report is available on line at The research highlights include studies of the rise of oxygen in Earth’s atmosphere more than 2 billion years ago; snowball Earth events when ice cover extended to the equator; the complex ecology of microbial mats; life beneath the sea floor; subsurface life that exists completely independently of the photosynthetic biosphere; the “rare biosphere” that co-exists with more familiar life in the deep ocean; organic compounds in comets, studied both observationally and in detailed laboratory investigations of returned samples; and methane in the atmosphere of Mars, indicating that Mars is geologically or biologically active, or perhaps both. There are close to 50 papers cited in association with these highlights. Although there are many, many other publications that could cited as well (as pointed out by Shawn and Linda), this list is a manageable place to start.

    In the interest of full disclosure, I’m the current Director of the NAI.

  24. Something more recent, with 59 citations in google scholar.

    Johnson et al. 2008. The Miller volcanic spark discharge experiment. (Science)

    though I'm not sure if you'd consider it "astrobiology". And since science has not discovered life outside our planet, much of these data is useful in the "search for life in other planets"

    It's easy to cling the "astrobiology" keyword. But the truth is that good origin of life or astrobiology research is very hard to do regarding experimental design, controls and conclusions.

  25. Astrobiology is an interdisciplinary endeavor that integrates and synthesizes information from many fields. Its function is to bring scientists together from diverse backgrounds. Therefore, to ask for specific examples of "astrobiology research" is to miss the point of what astrobiology is. Astrobiology includes everything that is relevant to studying biology on this planet or other planets. Any paper that affects our concept of the nature of life in the universe is a good astrobiology paper. In this context, this paper is definitely an astrobiology paper:

    Watson J.D. and Crick F.H.C. (1953). "A Structure for Deoxyribose Nucleic Acid" Nature 171 (4356): 737–738.

    Is that good enough for you?


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