No, NASA photos are not evidence of fungus growing on Mars, sorry

Despite what you might have read, the claims about life on Mars are shoddy and unscientific.

Jackson Ryan Former Science Editor
Jackson Ryan was CNET's science editor, and a multiple award-winning one at that. Earlier, he'd been a scientist, but he realized he wasn't very happy sitting at a lab bench all day. Science writing, he realized, was the best job in the world -- it let him tell stories about space, the planet, climate change and the people working at the frontiers of human knowledge. He also owns a lot of ugly Christmas sweaters.
Jackson Ryan
5 min read

Martian "blueberries" are rocky spheres that form on the surface of Mars. 


Mars is very in right now. NASA's Perseverance rover is up there searching for life, and the agency's Ingenuity Mars helicopter is pulling off daring aerial feats. But on Wednesday, Mars appeared in the news for all the wrong reasons. According to websites like the Daily Mail, scientists were making a pretty wild claim: Fungi were alive and well on the red planet. 

The first thought: Ah shit, here we go again

The "mushrooms on Mars and fungi on Venus" theory is a worn-out, debunked idea that appears like clockwork, about once a year. The headlines certainly are interesting: Imagine if we found fungi on Mars or Venus! It would literally rewrite our ideas about life in the cosmos -- but the articles rarely interrogate the scientific evidence for the wild claims.

Part of me wants to let it slide because in some cases any publicity really is good publicity, but this is bad science and some websites have erroneously headlined articles with "Scientists Found Evidence of Fungus Growing on Mars" when that is simply not the case.

So let's pull back the curtain and explain what is really going on (again!)

The 'Space Tiger King'

At the center, or sometimes just off to the side, of these outlandish claims is a man named Rhawn Gabriel Joseph. 

According to his webpage "brainmind.com," Joseph is a lapsed neuroscientist who made major contributions to the field of neuroplasticity in the 1970s. Joseph has, for over a decade, published claims about life on other planets on his website and in pseudo-scientific journals he oversees. 

His assertions sometimes make it to the big leagues and spill over into the press but, for the most part, they haven't landed in legitimate scientific journals or been scrutinized by other experts in space science.

Until 2019, when Joseph's claims really hit the big leagues. In November of that year, Joseph got a piece through peer review and into the journal Astrophysics & Space Science. Last June, I published a piece on Joseph and these claims, which eventually led to the journal retracting Joseph's article, stating "the article proffers insufficient critical assessment of the material presented and literature cited, and fails to provide a solid underpinning for the speculative statements made in the article which, in their view, invalidates the conclusions drawn."

But on Wednesday, Joseph's claims made it into another journal, known as Advances in Microbiology.

NASA Perseverance rover and Ingenuity helicopter explore the wilds of Mars

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Day of the truffles 

Advances in Microbiology is a relatively obscure journal published by Scientific Research Publishing, which is headquartered in China and has previously been caught out for republishing scientific articles, according to Nature. It has been accused of being a predatory publisher, charging scientists fees to be published in its journals without checking the quality of the submitted papers.

The new paper, dubbed "Fungi on Mars? Evidence of Growth and Behavior From Sequential Images" and available on ResearchGate, rehashes some of the old arguments for life on Mars, using inaccurate methodology to draw its conclusions. For the most part, Joseph and his co-authors use images obtained by NASA rovers and draw red lines and arrows to point out features they believe correspond to fungal growth. 

"Claiming that mushrooms are sprouting all over Mars is an extraordinary claim that requires better evidence than an analysis of photographic morphology by a known crank who has claimed, on the basis of the same kind of analysis, that he has seen fields of skulls on Mars," says Paul Myers, a developmental biologist at the University of Minnesota, Morris, who has followed Joseph's work in the past.

One experiment, performed by the authors, is to analyze the size and movement of "spherical specimens" in the paper. It routinely references previous work by Joseph as evidence for its conclusions. The team suggests it "would be surprising" if there were no life on Mars -- but this is not true. We have mountains of data showing the conditions of Mars are not conducive to life as we know it. Could fungi get around these conditions? Perhaps, but the evidence for that is thin.

After being alerted to the new paper on Wednesday, I sent emails to the associate editors-in-chief of Advances in Microbiology,  asking for clarification around the peer review process. They have not responded to requests for comment. 

I also emailed members of the editorial board listed on SCIRP's website, including Jian Li, a microbiologist at Monash University in Australia. He says he has not been on the journal's editorial board "for at least five to six years" and has not handled any of the papers in the journal. 

Bad science

One of the bigger problems in publishing about Joseph's claims is allowing bad science to make its way to the public. 

The pandemic has shown us that misinformation can be harmful, eroding the confidence in science, researchers and institutes. We've seen, time and again, how erroneous reports can go viral and then later be used to suggest scientists are backflipping on previous claims. To be clear, there's no backflip here. The majority of scientists agree that the conditions on Mars' surface are not great for fungi to flourish.

"All available evidence suggests the surface of Mars is not hospitable to life," says Brendan Burns, an astrobiologist from the University of New South Wales in Australia.

When publications promote the unscientific "mushrooms on Mars" theory without critique, it can be damaging for scientists like Burns and organizations like NASA, who are attempting to find legitimate signs of life on other planets

If we were to find life elsewhere in the solar system, it wouldn't first appear in the Advances in Microbiology journal. Readers should remain skeptical of any fungi claims they see -- especially those promulgated by a single group of scientists. 

And look, I'm totally happy to be wrong here. If it turns out this is fungus on Mars, I will be the first to say "we stuffed up."

I'm hopeful that NASA's Perseverance rover, which is rolling along an ancient Martian lakebed, might be able to find the first signs life once existed on the red planet. China's soon-to-be-delivered rover, Zhurong, could also help understand whether Mars harbored alien life forms. We'll have to wait and see.