Science Week — #4

Picture this: you peel back a rainforest like a translucent curtain and suddenly see straight lines, circles, and entire ancient designs stitched into the ground. No machete, no mud, just lasers from the sky. That’s the promise of lidar mapping, and this week it helped researchers uncover nearly four hundred previously unknown geoglyphs in the southwestern Amazon.

The numbers are striking. Almost four hundred new earthwork designs, dated to roughly 600 BC through about 850 AD. That’s a span of well over a millennium. These aren’t small doodles either—they’re engineered shapes etched into the landscape, and lidar’s ability to see through the canopy is what makes them visible at scale.

It’s like we finally got the rainforest to stop hiding its diary. And hey, welcome back—this is episode 4, our science of the week for August 4. I’m Grace, he’s Daniel, and we’ve got a lot to get into: archaeology lit up by lasers, hard evidence of smallpox from colonial Chile, a Moon impact science moment, a rescue spacecraft that needs rescuing, and more.

The Amazon geoglyphs are a great place to start because they remind us that silence in the archaeological record doesn’t mean absence—it can mean the tools weren’t good enough yet. Lidar sends out pulses of light and measures their return time to map terrain in three dimensions, canopy and all. When you remove the trees virtually, the earthworks pop into view.

And it also expands the emotional scale of the Amazon story—beyond impenetrable wilderness into a place of deep design and memory. Earlier studies hinted that the region’s ancient earthworks were more extensive than anyone guessed. This week’s mapping makes that picture even sharper. It doesn’t answer every question about who built what and why, but it draws the map we needed to even ask those questions at the right scale.

Which is science at its best: first reveal the pattern, then start testing the explanations. For archaeology, that might mean ground surveys, careful dating, and cultural comparisons. For listeners, it’s a nudge to update mental maps—there was complex landscape engineering in parts of the Amazon long before modern times.

From lines on the land to letters in our DNA. Another story this week takes us to the Camarones area of northern Chile, where researchers extracted DNA from two colonial-era mummies and found a historic smallpox virus. That’s a sobering, precise confirmation that the disease arrived in the Americas with European contact.

The specificity matters. We’re not talking about circumstantial artifacts or case descriptions; this is genetic material from two individuals. For epidemiology, confirming the presence of a historic smallpox virus in that time and place anchors the timeline in a very literal way.

And it puts weight behind a narrative we often hear in broad strokes—disease arrival shaping entire histories. There’s something both clinical and intimate about it: centuries later, the virus leaves a trace that can be read.

Methodologically, it’s also a reminder that ancient DNA studies have advanced to the point where we can recover and identify viral sequences from human remains, not just human ancestry. But I want to be clear about boundaries here: the sample size in this announcement is two mummies. That’s strong evidence for presence, not a full reconstruction of spread or mortality. It confirms that smallpox was there; it doesn’t, on its own, quantify impact or sequence exact routes of transmission.

Still, the directness changes the tone. It’s one thing to say “smallpox likely arrived with contact,” and another to say “we found the virus in these two colonial-era individuals.” That’s the difference between a history book paragraph and a lab result.

And it shows how multiple lines of evidence—documents, archaeology, and now pathogen DNA—can interlock. Each has its limits; together, they tighten the picture.

Speaking of threads coming together, the global question about the origins of the COVID-19 pandemic was back in the news. The World Health Organization said the balance of scientific evidence points to a natural animal origin for SARS-CoV-2, citing recent studies and its own report. Its Scientific Advisory Group for the Origins of Novel Pathogens contributed the assessment after reviewing three years of research.

Language matters here. “Balance of scientific evidence” is a weight-of-evidence conclusion—it says what’s currently most supported, not what’s proven beyond doubt. It’s an assessment, based on multiple studies and the WHO’s prior work, that a zoonotic origin—meaning spillover from animals—is the likeliest scenario.

Right, no cinematic reveal here, more like “this is where the scales point.” For people trying to keep score, that’s a reminder that science often closes questions gradually, not with a single drumroll.

Also important: this is a synthesis of existing research, not a report of a newly discovered animal reservoir or a definitive genetic marker. That’s because a lot of origin work depends on assembling many indirect clues—epidemiology, viral genetics, known animal hosts, and the plausibility of transmission pathways.

And the tone matters. An official body saying “based on what we have, natural origin is most likely” doesn’t end every debate, but it guides public understanding. It also underscores the need for surveillance in animal populations and at the human–animal interface—because whatever the precise origin pathway, preventing future spillovers is a very practical, here-and-now task.

And as with the mummy study, methods set the guardrails. Reviews can tell you the likely story arc, but they don’t substitute for fresh, on-the-ground data. That’s why continued research remains essential.

From viruses in history to hitchhikers on hulls. Researchers warned this week that thousands of cargo ships idling in the Strait of Hormuz and the Gulf of Oman could spread invasive marine species globally once trade fully resumes. Their advice is straightforward: prioritize hull cleaning, inspections, and monitoring.

Mechanistically, this is about biofouling—organisms that attach to ship hulls and thrive while the ship sits still. The longer a vessel idles, the more time those communities have to establish. When ships leave and visit new ports, those organisms can get a free ride across oceans.

It’s a classic “stability isn’t always safer” scenario. Still water, stationary ships—yet the risk accumulates quietly. And the proposed mitigations are not high glamour: clean the hulls, inspect, keep watch.

To be precise, this is a warning, not a report of a measured global spread event. The researchers are flagging a plausible, well-understood pathway and urging preventive steps. “Thousands” gives a sense of scale; the movement of that many ships after prolonged idling is a nontrivial biosecurity factor.

And because it’s global shipping, the ripple effects are, well, global. The prudent move is to act before waves of surprises hit ports that didn’t see them coming.

It’s a nice throughline with the earlier stories: when systems are large—ecologies, pandemics, trade—the best science often tells you where to reduce risk early, not after the fact.

Let’s look up. There’s a space story with a clear date and a literal impact. A SpaceX Falcon 9 upper stage is scheduled to hit the Moon on August 5, near Einstein Crater, at around 5,400 miles per hour. The expected result: a fresh crater, roughly up to 100 feet wide and about 16 feet deep. Not an everyday thing.

And it’s not just for spectacle. Observing the impact and its aftermath is scientifically useful. NASA’s Lunar Reconnaissance Orbiter is slated to capture images. Earlier reports also noted that NASA and South Korea’s Danuri mission would observe. This kind of controlled—or at least predictable—impact helps researchers study the lunar surface response and ejecta patterns.

The part of me that loved backyard science projects is cheering: you drop something, you watch what happens, you learn what the ground is made of. Except here the “ground” is the Moon, the “rock” is a forty-foot upper stage, and the high-speed camera is a spacecraft already in orbit.

For expectations, the speed and crater size are estimates. The location near Einstein Crater is a helpful landmark, but the exact morphology of the new impact feature will depend on local terrain and the stage’s approach. That’s exactly why you want an orbiter ready to take pictures afterward.

And beyond the numbers, there’s a line connecting the ground truth of ancient geoglyphs and this lunar crater: we learn by making careful marks, then reading them. Humans etched circles in Amazonian soil long ago; now a rocket stage will etch a circle in lunar regolith and we’ll read that, too.

With the key difference that the lunar mark isn’t a message—it’s a probe. The message is in the data we collect when we compare before-and-after images.

Also, the Moon continues to be a very patient collaborator. No press conferences, just quiet craters.

Another space story this week landed on the “things did not go as planned” list. NASA confirmed that the Katalyst LINK spacecraft—launched to boost the Swift Observatory—suffered reaction-wheel and thruster failures. The result: it’s spinning and only able to communicate intermittently.

For context, reaction wheels are internal flywheels that spin up or down to change a spacecraft’s orientation without firing thrusters. If both the reaction wheels and thrusters have issues, you lose your main tools for pointing and stabilizing. Earlier, Katalyst had reported thruster problems that sent the spacecraft into an uncontrolled spin.

Which is rough, because a “rescue tug” becomes the one needing the tow. Space is hard; steering in a vacuum at high speed with delicate hardware always has a failure mode lurking in the margins.

The practical implication is that intermittent communications limit the ability to correct the situation or carry out planned operations. I’ll stay within the reported facts: NASA confirmed the failures and the spin; Katalyst had already flagged the thruster problem. It’s a reminder of redundancy in spacecraft design—and of how critical attitude control is for almost any mission goal.

The human side of this is easy to feel. A lot of smart teams put a lot of thought into getting a helping hand up to Swift. When that hand starts tumbling, you can sense the collective breath being held at consoles across multiple time zones.

And we’ll emphasize: this is a developing technical situation. For our purposes this week, the confirmed state is spinning, with intermittent contact, following failures in both reaction wheels and thrusters.

Back on Earth, under the most extreme conditions humans have ever created, something new took shape. Researchers analyzing fallout particles from the 1945 Hiroshima bombing identified a previously unknown multicomponent metal alloy, formed in the blast’s extreme temperatures.

In simple terms, a multicomponent alloy is a mixture of several metals forming a single, stable material with its own structure and properties. Under normal industrial conditions, we carefully control compositions and temperatures to make alloys. In a nuclear explosion, conditions are uncontrolled—but the heat and pressure can still drive unique phases to form.

It’s sobering science: a novel material born in a catastrophe. Yet it’s important to catalog what nature—and our interventions—can produce. If microscopic particles collected from the environment retain such materials, they become archives of the event’s physics and chemistry.

The report we’re discussing is an identification step: researchers found a previously unknown alloy in fallout particles. That’s discovery, not application. It adds to the understanding of what can form under extreme temperatures, but it doesn’t claim immediate utility or a blueprint for reproducing the material in a lab.

And like the geoglyphs or the smallpox DNA, this is evidence you can point to: a thing that exists, with a pedigree written into its atoms. I find that idea both unsettling and rigorous. Science is not about moral endorsement—it’s about accurate description.

Also note the chain of work. Earlier analyses of microscopic particles from Hiroshima Bay had already revealed certain features; this latest report adds a newly identified alloy to the list. Each step refines the picture of how materials transform under extreme conditions.

The thread running through all of today’s stories is that the world holds records of itself—etched in earthworks, preserved in mummies, burned into fallout, written into ship hulls, and traced in lunar dust. Our job is to learn how to read.

So what did this week teach us about how the world works? First, tools matter. Lidar turns a forest into a readable page. Ancient DNA turns remains into historical documents. Orbital cameras turn a fleeting impact into a dataset. When methods evolve, history becomes legible in new ways.

Second, language matters. “Balance of evidence” is not a shrug; it’s a disciplined statement about what the data currently support. “Expected” and “scheduled” around a lunar impact mean estimates and plans, not guarantees. “Warned” about invasive species is a call to act early, not an after-the-fact obituary for a reef.

Third, humility matters. The Amazonian geoglyphs remind us we often underestimate past complexity. The smallpox DNA grounds difficult truths. The rescue tug’s troubles remind us: even with engineering stacked high, reality has the final say. And the Hiroshima alloy shows that knowledge can be born from tragedy—and it’s still knowledge we have to face squarely.

Finally, scale matters. Nearly four hundred earthworks is a lot. Two mummies is precise but small. Thousands of ships create a risk that crosses borders. A forty-foot stage hitting the Moon is both tiny in cosmic terms and large enough to be scientifically interesting. Keeping those scales distinct is what keeps science from turning into hype.

And because we’re all trying to make sense of a noisy world, there’s comfort in that measured cadence: look closely, weigh carefully, say exactly what you know. It’s less flashy than shouting, but it’s how we actually learn.

Plus, if you shout at the Moon, it never shouts back. The data do, though—if you listen the right way.

If you like your news checked and calm, come see us at factslane.com, and grab the app on the App Store or Google Play. It’s the best way to keep your curiosity fed without the sugar rush.

And if you want more good company in your week, check out our sister shows, Good Week and Tech Week—both smart, both grounded.

That’s our time. Thanks for spending part of your week with us. Stay curious, take good care, and we’ll see you next week.

Until then.