So, a team of scientists in the UK claims theyâve found evidence for alien life coming to Earth. According to their paper, published in the Journal of Cosmology (more on that in a moment) they lofted a balloon to a height of 22-27 kilometers (13-17 miles). When they retrieved it, they found a single particle that appears to be part of a diatom, a microscopic plant. This, they claim, is evidence of life coming from space.
Um, yeah. Except really not so much.
A Bit of Historyâ¦
First off, Iâll note that the team publishing this paper includes one Chandra Wickramasinghe. This is the same man who has claimed, time and again, to have found diatoms in meteorites. However, his previous claims have been less than convincing: The methodology was sloppy, the conclusions were not at all supported by the evidence, and heck, he hadnât even established that the rocks they found were in fact meteorites! He also has a history of seeing life from space everywhere based on pretty thin evidence.
Given that, any claims associated with his work should be taken with a large grain of salt. Moreover, this team published their results in the Journal of Cosmology, an online journal that doesnât have the most discerning track record with scienceâsee here and here and links therein (and even more in the links in the paragraph above) for plenty of evidence of this.
But what about their actual claims?
They found what appears to be a fragment of a frustrule, the hard outer casing around a diatom. It certainly does look like one. But is it?
Weirdly, they apparently didnât even check. Seriously, in the paper they describe the photo of the object and say [emphasis mine],
On one stub was discovered part of a diatom which, we assume, is clear enough for experts on diatom taxonomy to precisely identify.
That implies very strongly they didnât ask an expert in diatoms to look at their sample. Thatâs bizarre. If I were claiming this were an ET plant, thatâs the very first thing Iâd do!
Still, letâs go with it. Diatoms are endemic on Earth, found essentially everywhere there is water. Did this one come from Earth? They do claim they took precautions to make sure none could contaminate their sample, so thatâs good. I wouldnât rule it out, but again, letâs go with that as well. The diatom looks very like known species on Earth (they comment on this fact in the paper, actually). How would it get up to the stratosphere?
Volcanoes would be a possible mechanism, though they say no volcanoes had erupted recently, and claim that a particle that size would fall out of the stratosphere rapidly. But Iâm not so sure thatâs the case. They quote a paper showing how rapidly a particle would fall from various heights, and say the diatom would fall within hours. But I read the paper, and it assumes the atmosphere is stable and unmoving; it specifically mentions no other forces acting on the particle except gravity and buoyancy. There is, however, wind and turbulence in the stratosphere that could conceivably keep a tiny object like that aloft for quite some time. Iâm not saying it did, but thereâs no indication in their paper they firmly eliminated the possibility.
And just because they canât think of a way to get it up there doesnât mean there isnât one. Given the alternative is alien life, for which we have zero other evidence (despite their linking to Wickramasingheâs previous claims about diatoms in meteorites, which I am satisfied are wrong), they should try a lot harder to look for more mundane ways this beastie made it up there. They dismiss other pathways, just stating they wonât work, but Iâm unconvinced.
Clearly, though, they are. In the paper itself they stop just short of claiming itâs alien for sure, but in the press release they are not so circumspect:
In the absence of a mechanism by which large particles like these can be transported to the stratosphere we can only conclude that the biological entities originated from space.
In other words, if they canât figure it out, it must be aliens. This âgod of the gapsâ argument leaves me underwhelmed. Theyâre making an extraordinary claim: This diatom originated in space, perhaps in a comet, and got into the stratosphere as part of a meteor or meteoric material.
There are a lot of reasons to think this claim is unfounded, but one is right in their very paper. Look at the picture they published of the diatom (shown above): It appears clean, even pristine. As they themselves say,
It is noticeable that the diatom fragment is remarkably clean and free of soil or other solid materialâ¦
which would be incredibly unlikely if it did come from a comet or a meteoroid. Why wasnât it embedded in some bit of rock? That point works against them more than it supports their claims.
It seems to me to be far more likely that like the other claims about diatoms from space, this is actually a case of one from Earth getting into their sample.
Iâll note that I find the idea of panspermiaâlife on Earth originating in spaceâreally interesting. We certainly have good circumstantial evidence life could exist in space; conditions on Mars looked pretty good a billion years ago, and weâve found amino acids in comets and meteorites. What we donât have is direct evidence.
Panspermia is worth investigating, but itâs worth investigating correctly. Outrageous claims on thin evidence with huge conclusion-jumping donât comprise the best way to do it. Stories like this one are sexy and sure bait for an unskeptical media, of course. But at the very least they donât help the public understand science and the scientific process, and I know some scientists take an even dimmer view of it (for example, read this, and this).
The lead author, Milton Wainwright of the University of Sheffield, says he is â95% convincedâ the diatom didnât come from Earth. That may be the case, but the evidence given in the paper doesnât support it.