By Caroline Delbert
Could there be mushrooms on Mars? In a new paper, an international team of scientists from the U.S., France, and China has gathered and compared photographic evidence that they claim shows fungus-like objects growing on the Red Planet.
In their paper, which appears in Scientific Research Publishings Advances in Microbiology, the scientists analyze images taken by NASAs Opportunity and Curiosity rovers, plus the Mars Reconnaissance Orbiters HiRISE camera. The objects in question showchalky-white colored spherical shaped specimens, which the Mars Opportunity team initially said was a mineral called hematite.
Later studies refuted the hematite claim. Soon, some scientists coined the termMartian mushrooms to describe the mysterious objects, because of how they resemble lichens and mushrooms, while in another study, fungi and lichen experts classified the spheres aspuffballsa white, spherical fungus belonging to the phylum Basidiomycota found on Earth.
In the new paper, the scientists point to a set of Opportunity photos that shows nine spheres increasing in size, and an additional 12 spheres emerging from beneath the soil, over a 3-day sequence. The researchers claim Martian wind didnt uncover the amorphous spheres, and that theyexpand in size, or conversely, change shape, move to new locations, and/or wane in size and nearly disappear.
Many of these ground-level spherical specimens also have stalks or have shed portions of their outer membranespossibly crustoseand are surrounded by white chunks and fluffy spore-like material that may consist of leprose.
Crustose and leprose are kinds of fungus surface textures, where crust or scales form and can flake away.
The presence of these peripheral parts is important, the scientists say, because it helps them make the case that what were seeing really is fungus instead of simply some spherical rocks. Mushrooms grow and reproduce like gangbustersits one of the defining characteristics of the entire family of fungi. Small mushrooms grow in about a day, while large mushrooms take up to 4 days.
In their research, the scientists carefully document all the ways their proposed fungi change from one photo to the next.White amorphous mass alters shape, location, and almost completely disappears from inside the crevice of a rock shelter over a three day (Sol) period, they explain of one image set.
Besides something like a gust of wind blowing away loose sand, fungi are one of the only living things that could experience such noticeable growth and change in just a few days.
The scientists acknowledge theevidence they present isnt ironclad, and seem to predict the scrutiny that will inevitably come with their paper, writing thatsimilarities in morphology are not proof of life.
It is possible that all the specimens presented here are abiotic. We cannot completely rule out minerals, weathering, and unknown geological forces that are unique to Mars and unknown and alien to Earth. However, growth, movement, alterations in location and shape, constitute behavior, and coupled with life-like morphology, strongly support the hypothesis there is life on Mars.
But if there really were mushrooms on Mars, what would that mean in a future where humans hope to settle on the Red Planet? Well, the scientists say many fungi on Earth are also extremophilesmeaning organisms that can thrive in conditions consideredextreme in terms of the usual building blocks of life. So to find mushrooms on Mars is perhaps less surprising than we think.
This is not the first time that these controversial photos have made their rounds in the media. In May of 2016, Dr. Rhawn Gabriel Joseph provided evidence and reported that 40 experts in fungi and 30 experts in geomorphology, after examining photos of Martian specimens taken by NASA, formed a statistically significant consensus that there is a high chance of life on Mars.
In February of 2019, Dr. Joseph and four colleagues published a major monograph detailing their finding in the Journal of Astrobiology and Space Science Reviews, 1, 40-82, 2019: Evidence of Life on Mars: Viking LR, Meteor ALH8401, Stromatolites, Methane, Lichens, Fungi.
However, the monograph was promptly retracted after finding the paper 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.
Dr. Josephs latest paper was published in the journal Advances in Microbiology, a journal headquartered in China thats been criticized for republishing existing articles, as Nature reported back in 2010.
Nevertheless, until we actually land people on Mars and are able to collect samples and check for ourselves, the idea that life of any sort on Mars is still up in the air. Scientists, however, should allow themselves to keep an open mind on whether life on Mars is possible, rather than immediately shooting down any theories that fly in the face of “conventional wisdom”
In his 2018 novel Red Moon, Kim Stanley Robinson imagined a moon settlement with fast-growing bamboo as its primary building material. Its not hard to imagine fungus used as anything from a building material, to an insulator, to even a hypothetical food source for Mars residents or their livestock animals.