Don't Believe the Hype: We Haven't Been Invaded by Space Algae

Finding extraterrestrial life has been NASA’s main goal in planetary exploration for decades. Missions have been designed to follow known life-giving materials like water in the hope of finding life or even evidence of past life on another world. But it’s a pricey way to do it. Launching robotic missions are expensive, especially when they fail or crash into their target planet. Wouldn’t it be great if evidence of extraterrestrial life came to us?

Well, that’s exactly what a new paper from an international team of astrobiologists is saying. It’s been floating around since it was published online last week, and it’s been gaining some pretty good traction online, feeding into the public’s fascination with alien life. Unfortunately, the study isn’t quite deserving of the hype.

One of the paper’s authors in Chandra Wickramasinghe, an astrobiologist who has made claims of finding extraterrestrial life in meteorites in the past. And the paper in question was published in the rather questionable the Journal of Cosmology. More on that in a minute. First, the scientists’ story.

On December 29, 2012, a meteorite burned through the skies of Polonnaruwa, Sri Lanka. It fell to Earth, where those who came into immediate contact with the rock were burned, according to the paper’s introduction. Police then came on the scene, collecting pieces of debris and distributing them among research institutions. One piece was delivered to Cardiff University, where the team had previously studied the freshly cleaved interior surfaces of meteorites using the Environmental Scanning Electron Microscope at the University’s School of Earth and Ocean Sciences.

Already the introduction is suspect. You’re very unlikely to be burned after touching a newly-landed meteorite. Yes, rocks falling from space turn into a fireball, but it’s a brief fireball, and it’s not hot enough to heat a rock that’s been chilled to near absolute zero in space. The heat of atmospheric entry may melt the rock’s outside, but it wouldn’t burn you.

So the team added some drama into their story. What’s the harm, right? None, really. The harm comes when they make a leap of faith assuming the rock they have in the lab is part of the December 2012 meteorite.

The team’s paper says they have unequivocal evidence, thanks to oxygen isotopes, that their rock is a space rock. The ratios, they say, match that of other confirmed meteorites. The problem is contamination. It’s really common for meteorites to become contaminated in our oxygen-rich environment filled with carbon based life forms, which throws off the oxygen isotope readings. It can be impossible to determine whether the rock came from space or if it’s a regular old Earth rock. Unfortunately, this paper doesn’t offer sound evidence that the rock is indeed from space.

As for the evidence of life the team has found inside their rock, the paper says they found extremely well-preserved fossils of diatoms, which are a type of algae. Finding this kind of biological evidence in a meteorite would be historic to say the least. But in light of the rock’s unconfirmed origin, it’s more likely the “fossil” is some kind of Sri Lankan algae that crawled into the rock and died. There are some pretty tiny things in this world that can worm their way into even the smallest places as long as they’re porous.

This isn’t the first time this group of scientists has claimed to have found life in this very rock. In January, Wickramasinghe was the lead author on a paper that made similarly baseless claims about fossilized life in a meteorite.

Despite the lack of solid evidence, these papers get passed around and people get really excited about alien life reaching Earth. As the team’s January paper said in its introduction, “the new data on ‘fossil’ diatoms provide strong evidence to support the theory of cometary panspermia.”

Cometary panspermia is the idea that extremophiles, life forms that can survive the effects of space, can travel through space locked in rocks. They arrive at planets as comets or meteorites. Following this explanation, populating the solar system becomes a matter of a planet being in the path of the right rock at the right time. (And having the conditions to support life, of course, but let’s just pretend for argument’s sake that its the 19th century and we think all planets can support some kind of life.)

Panspermia is an appealing prospect, knowing that life has a good shot of arriving on all planets and that the evidence can fall right into our laps. But it’s an hypothesis, and not one Wickramasinghe’s work lends any support to. In neither case, the January paper or the more recent publication, did the team consult experts in meteorites or diatoms. This isn’t peer reviewed science.

We haven’t been visited by aliens, either the death-ray wielding kind or the dead in a rock kind. At least, not yet. But there’s always that chance we’ll find evidence of something living in a rock from space yet.