Science Week — #17

Imagine being told fifteen times that your idea about where the machinery inside our cells came from was too out there—and then years later, watching the field come around and say, actually, that’s right. That’s the arc we’re starting with this week.

A timely reminder that good ideas can survive a long review process.

According to Yahoo, Lynn Margulis’ symbiogenesis theory—this idea that parts of our cells originated through symbiotic mergers—was rejected by fifteen journals before being published and later confirmed by research on mitochondria and chloroplasts. It had faced widespread skepticism, and then, slowly, it became accepted.

And that’s history, not a brand-new paper this week. But it’s a good case study in how evidence can shift consensus. Early resistance, later confirmation, and now a concept that frames how biologists think about the origin of key cell structures.

It taps into that bigger theme we love: science as a self-correcting process. Persistence, high-quality data, and time.

Also a good moment to mark where we are. This is episode 17, looking at the science of the week for November 3. And we’ve got a lot to unpack across health, climate, and space.

Including an astronaut who says a seven-hour walk outside a space station changed how he looks at Earth—because of course it did. But first, one more beat on Margulis. It matters because the idea affects how we think about collaboration in nature, right? Not just competition.

Yes—though we should keep our language precise. The concept proposes that organelles originated via symbiosis. The later confirmation mentioned in the Yahoo report anchored the idea with evidence. That’s the important piece: not just a compelling story, but supporting research.

And a nudge to anyone doing hard science: if the fifteenth “no” arrives, maybe the sixteenth submission is where it turns.

With the usual caveat: persistence helps, but data rules.

Data rules. On to health.

The health story that caught us this week comes from the University of Copenhagen. Researchers identified a decline in a mitochondrial lipid called cardiolipin as a driver of age-related muscle fiber changes. They reported that partially restoring this molecule in mice reversed muscle loss and prevented early death.

Important to stress: mice. The findings point to a potential therapeutic target, but this is preclinical. The report we have doesn’t list sample size or experimental duration, so we don’t know how big the effect was, how it varied across the cohort, or how robust it is across different mouse strains.

Still, it’s a striking result. Reversal of muscle loss and prevention of early death in an animal model is the kind of outcome that makes people sit up.

It is. But translation from mouse to human biology is a major step. We’d need replication, independent groups confirming the mechanism, toxicity profiles, dose-response curves, and then the long path of clinical studies if a therapy is envisioned. The summary we have doesn’t cover any of those.

Another caveat is the word “partially.” That suggests the intervention didn’t need to restore cardiolipin completely to see an effect in mice, which is interesting. But that’s as far as we can responsibly go on what’s in front of us.

Agreed. The mechanistic framing—decline in cardiolipin driving age-related muscle fiber changes—is a hypothesis supported by their data. Whether it generalizes beyond the experimental setting needs more work.

I like that it gives a concrete molecule to watch. Sometimes progress is about naming the thing. Now we can follow how cardiolipin shows up in future studies.

And track whether independent labs can reproduce the reversal of muscle loss in mice. Until then, promising but early.

Over to the planet we’re all standing on. Researchers at Caltech reported that smoke from the Eaton urban fire contained lead concentrations more than fifty times higher than typical wildfire smoke. They also found elevated chlorine, bromine, and arsenic.

That’s a stark contrast. The measurements were taken by an ASCENT monitoring station in Pico Rivera, which is part of the Atmospheric Science and—well, the program name is truncated in the report we have—but ASCENT is the system they used.

The point lands either way. Urban fires are not the same as wildfires, and this snapshot shows why. More than fifty times the lead you’d expect in typical wildfire smoke, plus those halogens and arsenic.

The report doesn’t cover health outcomes, exposure durations, or spatial dispersion. So we should avoid extrapolating. But from a monitoring and preparedness perspective, this is a reminder that smoke is not a single category.

It’s also a small piece of good news, in the sense that having a station in place to capture those measurements means communities can respond faster and more precisely.

Yes. Real-time or near-real-time measurements are valuable. The data here come from a specific event and location—Pico Rivera. The numbers emphasize how composition can vary dramatically from “typical” baselines.

And that word “typical” is doing a lot. Fifty times higher than typical wildfire smoke is not a nuance—it’s a klaxon. The elemental mix of what burns changes what’s in the air.

The next steps would be more stations, more events, standardized comparisons, and then policy that reflects compositional differences in smoke. The study summary doesn’t go into those steps, but they’re implied by the contrast.

For now, we have a clear signal: urban fire smoke can be chemically very different, and monitoring caught it.

Let’s leave the smoke and head to vacuum—for seven hours. Canadian astronaut Joshua Kutryk said a spacewalk on the International Space Station on October 29 gave him a new perspective on Earth. He and NASA astronaut Anil Menon completed the mission, and NASA and the Canadian Space Agency reported that the EVA lasted about seven hours.

A nice convergence of subjective experience and a tidy number: seven hours outside, and a reappraisal of the view of home.

It’s the kind of line that makes you stop. Someone spends a working day literally untethered from normal life, turns around, and says, I see Earth differently now. That’s science adjacent, but human at the core.

The report doesn’t list the specific tasks they completed, so we won’t speculate. What we do have are the duration, the date, and that reflection. The mission was completed.

There’s a quiet beauty to that. No exclamation points needed. Just: seven hours, a completed spacewalk, and a changed perspective.

It also pairs with our later items on spacecraft at the ends of their missions. Human spaceflight and robotic probes both feed perspective, in different ways.

Nicely put. And speaking of ends of missions…

This is a follow-up to something we covered earlier. NASA said the 1.5-ton Swift Observatory is expected to burn up during re-entry on November 4, with a low probability that any fragments will reach the ground.

Right. We talked about Swift last week, and what’s new now is the re-entry expectation—November 4—and NASA’s note on low probability of debris making it to the ground. The observatory launched in 2004, ended its scientific operations on October 20 after nearly two decades of observations of gamma-ray bursts and supernovae, and then entered the end-of-life phase.

There’s something elegant about that summary. Two decades of watching the most dramatic flashes in the universe, and then a carefully managed goodbye.

The probabilities matter. “Low probability” is not zero, but it’s meant to convey that ground risk is small. The report doesn’t quantify it, so we’ll stick with their wording.

We’ll keep an eye on how cleanly the burn-up proceeds, but as of now, the expectation is set.

And it’s a good time to appreciate that record: gamma-ray bursts and supernovae, nearly two decades. Not bad for a 1.5-ton spacecraft.

Not bad at all. From an orbiting veteran to the most distant traveler we’ve built.

NASA’s Jet Propulsion Laboratory in Pasadena, California said on November 2 that Voyager 1 will be one light-day from Earth on November 18, 2026. That’s about 16 billion miles, and it sets a new distance record for a human-made object.

The note also mentions a mid-October incident in which contact with Voyager was affected. The report doesn’t detail the cause or the resolution, so we won’t add anything there. The key point is the projection: one light-day by late 2026.

I love the phrasing “one light-day,” and that they translated it into miles—about 16 billion. It’s a unit that forces you to feel scale. A day of light’s travel.

It situates Swift’s goodbye too. One mission completing its arc in Earth’s neighborhood, another stretching a line out to a single day of light, which is a remarkable milestone.

And the reminder that this is a projection—“will be” in 2026—keeps us honest. It’s forward-looking.

Also worth noting: “new distance record for a human-made object.” That’s a clean superlative, anchored to a clear metric.

It makes you want to step outside and stare up, even though the spacecraft is well beyond what you can point to. That’s the gift of a number like that: it reframes the night sky.

And signals that, despite incidents and aging hardware, milestones are still being marked.

While we’re out past Neptune in our minds, astronomers using the Vera C. Rubin Observatory announced the discovery of 2026 ED138, a trans-Neptunian object that may be large enough to qualify as a dwarf planet.

“May be” is the operative phrase. Earlier reports indicated that the object, provisionally designated 2026 ED138, was identified from observatory data and that further observations are needed. So we’re at the candidate stage.

The best kind of “maybe” in astronomy: a new dot in the deep that could be a dwarf planet, pending more data.

And a nice example of how discovery pipelines work: detection, provisional designation, then follow-up to constrain size and other properties. The report doesn’t give measurements, so we won’t estimate.

It’s enough to know that the searchlight is working, and that the outer solar system still has surprises tucked away. Even the name—2026 ED138—feels like a placeholder that invites a story later.

Which will come, if and when the “may be” shifts to “is.” For now, it’s an announcement of a potential dwarf planet, pending confirmation.

Add it to the watchlist, right next to cardiolipin and Voyager’s itinerary.

Quite the shelf.

Let’s take a short detour into the physics of scale and endings, because both showed up all over this week. A “light-day” being about 16 billion miles is the kind of translation that helps anchor an abstract unit. And a 1.5-ton observatory burning up with a low probability of debris reaching the ground reminds you that even retirements are engineered.

And in between, a seven-hour spacewalk is both a human-scale shift in perspective and a carefully timed operation. The numbers themselves—seven hours, 1.5 tons, 16 billion miles—are concise anchors. They also keep us from drifting into hype.

We don’t need to add drama to space. The hard numbers already press the edges of a human imagination. One day of light’s travel. That’s enough poetry.

And it’s a helpful check on our health and climate stories too. “More than fifty times higher than typical wildfire smoke” is a precise contrast. “Partially restoring cardiolipin in mice reversed muscle loss and prevented early death” is an outcome tied to a model organism. In each case, the phrasing counts.

Which is why we read the verbs carefully on this show. “Reported,” “said,” “announced,” “may be.” Each one tells you how solid the ground is under the claim.

And how far you can responsibly walk on it.

Seven hours max.

Preferably with a tether.

Time to stitch these threads into one big picture. This week, we had a hard-won idea in biology—symbiogenesis—held up as a case where skepticism yielded to evidence. We had a mouse study pointing to cardiolipin as a driver of age-related muscle fiber changes, with an intervention that reversed muscle loss and prevented early death in that model.

We also had a precise warning signal from an urban fire: lead in smoke at more than fifty times typical wildfire levels, plus elevated chlorine, bromine, and arsenic, measured by an ASCENT station in Pico Rivera. And in space, a human reflecting on Earth after a seven-hour spacewalk, a veteran observatory preparing to re-enter with a low probability of debris reaching the ground, a pioneer probe on track for one light-day—about 16 billion miles—by November 18, 2026, and a potential dwarf planet, 2026 ED138, awaiting confirmation.

The throughline for me is humility. This is what the world is actually doing, not what we wish it would do. Cells carry a legacy of merger. Muscles age in ways that might be reversible in one animal model. Smoke chemistry can jump far beyond what’s “typical.” Machines retire, machines persist, new worlds flicker into view, and people come home from a walk outside a station saying, I see differently now.

And the method is consistent: observe, measure, qualify, repeat. When the data are preliminary, say so. When they’re projections, say so. When they’re confirmed, say that too.

Which is how we try to run this show. One careful week at a time.

Speaking of which, if you want a clean way to keep up without drowning in headlines, head to factslane.com or the apps on the App Store and Google Play. You pick what matters to you—topics, people, companies, places—and FactsLane tracks and catches you up with checked facts.

And if you like a weekly dose of good news or a tour through the tech week, check out Good Week and Tech Week. They’re thoughtful, grounded, and a nice complement to this show.

That’s it for us this week.

Stay curious, take good care, and we’ll see you next week.