|
Diatom shells have been found in the Earth’s stratosphere at a height of 27 kilometers. Since there have not been any violent volcanic eruptions in the last three years, the presumption is that they came from space, and probably from inside a comet, according to Professor Milton Wainwright (University of Sheffield, England), who is the lead author of a new paper titled, Isolation of a Diatom Frustule Fragment From the Lower Stratosphere (22-27 km) – Evidence For A Cosmic Origin (Journal of Cosmology, 2013, Vol. 22, pp. 10183-10188). Here’s how the report’s Abstract summarizes the discovery:
Sampling of the stratosphere at heights between 22 and 27 km was carried out in the UK on 31st July 2013 using balloon-borne equipment carrying aseptically clean electron microscope stubs onto which aerosols were directly captured. The experiment revealed the presence of a diatom frustule captured from a height of >25km. On account of the very short residence time of particles of diatom size and mass at these heights, we argue for its incidence from space, with a probable origin in the watery environment of a comet.
A frustule, for the benefit of those readers who may be wondering, is the hard and porous cell wall or external layer of a diatom. It’s principally composed of silica and is coated with a layer of an organic substance made of various polysaccharides. Diatoms comprise a major group of algae, and are mostly unicellular. The cell walls of diatoms display a wide variety of forms, but in the majority of cases they are almost (but not quite) bilaterally symmetrical, enabling one valve to just fit inside the edge of the other. Diatoms can be found in the oceans, in freshwater, in soils and on damp surfaces.
The paper adds that the diatoms retrieved by Professor Wainwright and his team apparently belong to the genus Nitzschia (pictured above, courtesy of Hannes Grobe/AWI and Wikipedia), judging from their shells. Nitzschia is a common marine diatom, found mostly in colder waters. One species is capable of mutiplying exponentially, even at a temperature of −6 degrees Celsius!
A report in Sci-News.com (19 September 2013) describes how the diatoms were retrieved from the stratosphere by balloon:
The balloon was launched near Chester, UK, and carried microscope studs which were only exposed to the atmosphere when the balloon reached heights of between 22 and 27 km.
The balloon landed safely and intact near Wakefield, UK. The scientists then discovered that they had captured a diatom fragment and some unusual biological entities from the stratosphere, all of which are too large to have come from Earth.
According to a report by Tom Mendelsohn in The Independent, the diatom shells are very clean, making them unlikely to be terrestrial, and they may even contain DNA:
The organisms are probably not alive, but, excitingly, probably do contain DNA. Similar ones harvested during an earlier experiment have contained the chemical, which is one of the fundamental building blocks of life on earth…
“The particles are very clean,” added Prof Wainwright. “They don’t have any dust attached to them, which again suggests they’re not coming to earth. Similarly, cosmic dust isn’t stuck to them, so we think they came from an aquatic environment, and the most obvious aquatic environment in space is a comet.
Mendelsohn notes that “the Journal of Cosmology has had its reputation called into question more than once by other members of the scientific community.” And a reader of the Sci-News.com report has pointed out that this isn’t the first time that Professor Wainwright has retrieved organisms at high altitudes which he claimed were from space: in 2002, he co-authored a report detailing how microorganisms had been retrieved from a height of 41 kilometers. In that report, Professor Wainwright acknowledged the possibility of contamination – as he did in a subsequent 2006 report. But on this occasion, he was much more careful, as he notes in his Journal of Cosmology paper:
A separate control flight was made to the stratosphere prior to the sampling flight, when the draw was not opened, but all other sampling procedures were observed. No particulate matter was found (using the SEM) on any of the unexposed microscope studs, showing that the draw remained airtight and that none of the stubs was exposed to particles at, or near, ground-level or at any height up to the stratosphere. These results also show convincingly that no particles contaminated the stubs during any of the sample processing procedures, thereby demonstrating that the scrupulous procedures used to prevent ground level contamination proved effective and that no such contamination occurred.
And for those readers wanting technical details, here are some excerpts from the body of the Journal of Cosmology paper by Professor Milton Wainwright and his team:
Here we report, using a relatively simple low-cost stratospheric sampling methodology, the isolation of a particle which, beyond doubt, is a fragment of a diatom frustule. We believe that this is the first ever report of the isolation of a diatom frustule from the stratosphere and we provide arguments to support our view that this biological particle may have arrived from space…
Figure 1 shows a scanning electron micrograph of the surface of an SEM (scanning electron microscope) stub which was exposed to the lower stratosphere (at a height of between 22-27 km) over Northern England on 31st July 2013. On one stub was discovered part of a diatom which, we assume, is clear enough for experts on diatom taxonomy to precisely identify. Similarities with a broad class of diatoms belonging to the Nitzschia species point to a probable tentative identification with a terrestrially known similar organism. The diatom in Fig.1 is obviously incomplete and probably does not contain a protoplast, and is therefore part of an empty frustule. It is not known if the diatom reached the stratosphere as a fragment or whether it arrived with a viable protoplast encased within an intact frustule…
There are clearly two possibilities to explain how the diatom isolated here reached the lower stratosphere; either it was lofted from Earth’s surface, or it was falling to Earth from space. Occam’s razor might suggest to some that the latter possibility occurred and that the diatom was in some way lofted from Earth to the stratosphere. The most obvious means by which a particle of the size and mass of the diatom fragment shown in Fig.1 could be lifted from Earth’s surface to, say 25 km, is by a violent volcanic eruption. However, no such eruption appears to have taken place in the months prior to the short period of our stratosphere sampling. The residence time in the stratosphere of such a relatively large and dense particle as the diatom fragment would have been very short…
…[W]e calculate that a diatom of radius in the range 3-10 micron would fall at an average of 1 cm/s at a height of 20 km, and that the residence time of any particle lofted to this height is about 6 hours. The conclusion is that even if a major volcanic eruption occurred a few days before the sampling event, no particles of the size of the diatom fragment resulting from it would have been retained in the stratosphere at the point of sampling. There is no record that any such eruption took place. In fact, the most recent major volcanic activity occurring close to the UK was the Evjafjallajokull volcano, which erupted on Iceland in early 2010 and caused considerable problems to commercial flights. There is certainly no way, as is often casually suggested by unthinking critics, that a particle, like the one seen in Fig.1, could simply float into the stratosphere or be carried by winds up to heights well above the tropopause. It is also unlikely that the fragment could have come from commercial aircraft, which fly below well below our stratospheric sampling height. Other possible mechanisms by which the particle could theoretically be carried into the stratosphere include gravito-electrophoresis and the involvement of blue lightning (Wainwright et al, 2004), but even these would probably only theoretically elevate particles of radii greater than 1micron to the stratosphere. It is noticeable that the diatom fragment is remarkably clean and free of soil or other solid material, thereby suggesting that it originated from a water environment, rather than being associated with volcanic debris; in relation to an Earth origin it could have resided in the oceans, while a comet could have provided a cosmic origin for the diatom fragment (Hoover et al, 1984; Wickramasinghe and Hoyle, 1999).
I should point out that according to the Volcano Disovery news for July 2013, the greatest height reached by ash particles in any volcanic eruption that month was 13 kilometers. That’s well below the height of 25-27 kilometers, at which the diatom shells were retrieved by Professor Wainwright and his team.
The following excerpt from the Conclusion of Professor Wainwright’s report in the Journal of Cosmology is highly relevant to the Intelligent Design debate:
Of course the standard mode of rebuttal to a space origin for the fragment is to assert that Occam’s razor informs us that there must be a mechanism for lofting particles of this size from Earth to the stratosphere and that our findings are proof of the existence of such an unknown mechanism, the search for which must now begin. While an Earth–bound origin for this diatom fragment may be invoked in order to meet criteria of parsimony or conservatism, we argue that since no major violent volcanic event or other atmospheric event occurred close to the time and place of sampling, the diatom fragment shown in Fig. 1 must most plausibly have come from space – thus establishing consistency with theories of cometary panspermia (Hoyle and Wickramasinghe, 2000; Gibson et al, 2011).
The good news, according to the Sci-News.com report, is that it’s possible to test experimentally whether the diatom shells come from space:
“…The absolutely crucial experiment will come when we do what is called ‘isotope fractionation’. We will take some of the samples which we have isolated from the stratosphere and introduce them into a complex machine – a button will be pressed. If the ratio of certain isotopes gives one number then our organisms are from Earth, if it gives another, then they are from space. The tension will obviously be almost impossible to live with!” Prof Wainwright said.
Until then, stay tuned!
UPDATE 1: Terry Kee, President of the Astrobiological Society of Britain and Reader at the University of Leeds, has written a skeptical response to Professor Wainwight’s paper, available here. His central argument is that since we already know that Earth is teeming with life and we don’t know of anywhere in space that has life, Earth seems a better place to look, when attempting to account for the presence of diatoms 27 kilometers up in the atmosphere. Unfortunately, the remarks he makes about the reliability of the Journal of Cosmology are regrettably ad hominem.
UPDATE 2: I have been informed unofficially that diatom frustules were also found some years ago (correction: last year) on a meteorite from Sri Lanka -the Polonnaruwa meteorite – and that the oxygen triple isotopes do not match the terrestrial fractionation, and carbon isotopes are likewise non-terrestrial. If that’s correct, and if ‘isotope fractionation’ testing of the latest sample recovered by Professor Wainwright reveals the same thing, then the consequences would be pretty awesome.
UPDATE 3: For a more skeptical view on the Polonnaruwa meteorite, see here.