Mystery and Science by Carol Potenza
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In 1948 New Mexico, a disgraced physics student is hiding on her family ranch—until something not‑quite‑human crashes onto her land and blows her quiet exile to pieces. As Francie Cortez battles to save the only home she has left, she’s dragged into government secrets, the fallout from Roswell, and a buried family past that won’t stay dead. Caught between a menacing “spaceman” and a charming soldier with secrets of his own, Francie must decide what—and who—she’s willing to risk for the truth.
For readers who love smart, character‑driven historical fiction laced with Roswell‑era secrets, eerie SF twists, and a slow-burn romance that could rewrite one woman’s future.
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We may not be alone …
With all the Roswell stuff, you might think I mean “out there.” But I mean inside our bodies.
Hidden Guests by Lise Barnéoud (2025) dives into biology that makes logical sense but isn’t something I’ve ever really thought about. A lot of us are walking around with other people’s cells living inside us, a phenomenon called microchimerism.
Barnéoud follows the scientists who first found fetal cells in mothers and maternal cells in children, then realized these hitchhiking “hidden guests” can linger for decades, tuck themselves into different organs, and sometimes help with repair or tip the balance toward autoimmune disease. (It would explain a lot)
These microchimeric cells can speed wound healing, nudge the immune system to accept transplanted organs, and generally wreck the notion that our defenses simply sort everything into “self” and “non‑self.”
And because that’s not wild enough, Barnéoud dives straight into the melodramatic: if our bodies are mosaics built from relatives’ cells and pieces of us can go on living inside someone else, what does that do to our ideas of identity, individuality, and where life—and death—actually begin and end?
Manganese, Dark Oxygen Production, and the Periodic Table of DEATH and Mystery
The discovery of dark oxygen production has been so exciting and, well, revolutionary. I mean, biochemistry has long taught that photosynthesis—and its dependence on light—is the major generator of the oxygen that fills Earth’s atmosphere and therefore is directly linked to life on this planet. The claim that another major method of oxygen generation had been found in the depths of our oceans challenges a scientific dogma that is almost sacrosanct, and it was published Nature.
Nature Journal? Is that important?
Why, yes. Publication in Nature (UK) or Science (US) is a big deal. These journals are among the most selective and widely read in all of science, so publication signals that the work is both rigorous and broadly important. Their articles are highly cited and closely watched by other scientists, funding agencies, and the media, which can boost a researcher’s visibility and career opportunities. It’s like:
The scientific equivalent of a Pulitzer Prize–level spotlight.
The research equivalent of a best-picture nomination at the Oscars.
Like your album going multi-platinum—among scientists.
After publication, the dark oxygen paper shot into the top tier of 2024 articles because the research is so “sexy.” There are online newspaper posts, YouTube videos, podcasts, excitement in the sci-fi writing community—
Total scientific clickbait.
But before we fall madly in love with this idea, let’s meet manganese
Manganese (Mn) is a silvery‑gray transition metal in group 7, period 4 of the periodic table with atomic number 25 and an atomic weight of about 54.94. One of its earliest uses was by prehistoric cave painters of the Lascaux region of France around 30,000 years ago. Isolated in 1774 by Swedish scientist Johan Gahn, it is moderately abundant in Earth’s crust (~0.1% by weight), occurring mainly in oxides (MnnOm) and hydroxides (Mnn(OH)m)—you also might remember pinkish manganese chloride (MnCl2) crystals in a chemistry set you got for Christmas or your birthday.
It’s especially concentrated in deep‑sea polymetallic nodules (we’ll come back to these in a sec). Manganese melts at ~1,245°C and boils at ~2,060 °C, so it’s great as a steel hardening alloy—the Romans used it in their weapons, and look how far they got. But a lot of its technical value is due to its multiple oxidation states, most commonly +2, +3, +4, and +7, which means a lot of electrons can flow through it. Electron flow means electrical generation and … batteries (like alkaline cells using MnO₂ as cathode material).
In biology, manganese is essential to life. It’s a cofactor for various enzymes and, critically, sits at the heart of the oxygen-evolving complex of photosystem II, where a manganese, calcium, and oxygen cluster (Mn₄CaO₅) helps split water into oxygen during photosynthesis or Light Oxygen Production (LOP). While trace manganese is a necessary micronutrient for human health, excessive exposure (especially airborne in “occupational” settings) can be neurotoxic, leading to manganism, a Parkinson‑like syndrome.
Back to deep‑sea polymetallic nodules, manganese, and Dark Oxygen Production
Deep-sea polymetallic nodules are potato-sized lumps of rock that sit loose on the abyssal seafloor, typically 4,000–6,000 meters (~2.5–3.7 miles) down. They grow over millions of years as metals precipitate from seawater around a core. They’re unusually rich in nickel, cobalt, copper, and manganese—all the elements needed for batteries (think energy generation for artificial intelligence), renewable energy tech (solar, wind), and electronics.
Because each field of these nodules (thousands and thousands of them) on the sea floor can contain very high concentrations of battery metals, countries, companies, and researchers see them as a key source for our energy transition from fossil fuels to “clean” energy. Harvesting these nodules could also decrease terrestrial mining in sensitive areas.
But these fields aren’t sterile. Nodules act as habitats for deep‑sea animals and microbes (another thing we’ll get back to), creating unique environmental communities that don’t exist on the surrounding soft mud—so nodule fields themselves could be considered “sensitive areas.”
Studies on the impact of nodule mining are ongoing, and many are funded—surprise—by mining companies. One high-profile example is Sweetman, A.K., Smith, A.J., de Jonge, D.S.W. et al. Evidence of dark oxygen production at the abyssal seafloor. Nat. Geosci. 17, 737–739 (2024).
Sweetman et al. used a common method to measure oxygen in their study: Benthic chambers. Briefly, imagine putting an upside-down mixing bowl on the seafloor, trapping a patch of water and sand—or polymetallic nodules—so you can watch how they “breathe” over time. The chamber is a sealed, usually clear dome or cylinder pushed into the seabed that encloses sediment, organisms, and the water above, so scientists can track how gases like oxygen change inside without disruption from waves or currents. Sensors inside constantly record oxygen levels, letting researchers see whether life in the sediment is using up oxygen (as expected) or whether something in that little patch is mysteriously making more.
To support such a bold claim as dark oxygen production, rigorous repetition and well-designed controls are essential. Doing that kind of work on the abyssal seafloor, miles beneath a research vessel, is anything but trivial or easy.
What Sweetman’s “dark oxygen” study claims
Sweetman’s team placed benthic chambers on nodule-rich abyssal seafloor in the Clarion‑Clipperton Zone, an area rich in polymetallic nodules. They expected to see oxygen slowly decrease inside the chambers as microbes respired. Instead, in several chambers, dissolved oxygen rose over two days, even though there was no sunlight and no photosynthesis at those depths.
Unexpected? Oh, yeah.
Since the seafloor in the CCZ is carpeted with polymetallic nodules containing the same manganese and other metals used in both electrical current generation AND photophysiologic light generation, the team proposed that these nodules act like tiny “geobatteries”, generating electrical currents that split seawater into hydrogen and oxygen inside the chambers(!)
Sweetman et al. even tested the generation of electricity in polymetallic nodules in the lab and found one nodule that generated 0.95V. Not enough to split water to oxygen and hydrogen (~1.5V is needed for that), so they hypothesized that electrochemical reactions on and between nodules might be driving oxygen production.
And, because this oxygen would be produced in total darkness and potentially support seafloor life or even have implications for how early aerobic life could have started on Earth, they called it “dark oxygen,” suggesting it might be a previously unrecognized oxygen source in the deep ocean.
This finding is ground-breaking and is making scientists rethink everything from the start of life on Earth to the potential of life on dark moons and planets …
Until you read the rebuttals to the article. They are strong because they argue that Sweetman et al. did something researchers are not supposed to do: they discarded data that didn’t support their hypothesis.
Which we’ll hear about in the next episode of the Periodic Table of DEATH and Mystery. Oh. And those microbes on the deep-sea floor? Could they be the source of oxygen instead of the nodules? We’ll learn something about that, too.
Thank you for getting ALL the way to the bottom! And as always, thanks for reading my books.
