Welcome to Peer Review'd, the podcast where we dig into the latest and most fascinating science news from around the world. I'm your host, and today we have an absolutely packed episode. From the oldest artwork ever discovered to impossible atmospheres on distant planets, and from ancient antibiotics to revolutionary cancer treatments — let's dive in.

Let's start with a discovery that literally rewrites the story of human creativity. Researchers have identified a 67,800-year-old hand stencil in Indonesia, and it's now officially the oldest known cave art ever found. What makes it even more intriguing is its unusual, claw-like shape, which hints at early symbolic thinking and possibly even spiritual beliefs among our earliest ancestors. This discovery also strengthens the argument that humans reached Australia at least 65,000 years ago. Think about that — nearly 68,000 years ago, someone pressed their hand against a cave wall and left a mark. That impulse to create, to say 'I was here,' appears to be one of the most ancient things about us.

Staying in the ancient past, a new study is challenging one of archaeology's most foundational ideas — the timeline of the First Americans. Research led by a University of Wyoming archaeologist, focusing on an ancient site in Chile, is questioning whether the Clovis people were truly the first settlers of the Americas. This adds to a growing body of evidence suggesting people arrived in the Americas much earlier than the Clovis-first model proposes. History, it seems, keeps getting older.

And speaking of ancient humans doing surprisingly sophisticated things — Neanderthals may have been using birch tar as an antibiotic. A study from universities in Cologne, Oxford, Liège, and Cape Breton recreated birch tar using Neanderthal techniques and tested its antimicrobial properties. We already knew Neanderthals used birch tar as a kind of adhesive for their tools, but this research suggests it may have served a medicinal purpose too. So next time someone implies Neanderthals were primitive, you might want to mention their potential pharmaceutical knowledge.

Now let's talk about something that's rewriting physics. Researchers have discovered friction without contact — yes, you heard that right. Two magnetic layers sliding past each other experience resistance driven entirely by magnetic interactions, with no physical touching required. Their internal forces constantly compete and rearrange, creating a surprising peak in friction at certain distances rather than a steady increase. This breaks a 300-year-old law of physics. It's a reminder that even the most well-established rules in science are still subject to revision when someone looks closely enough.

Up in space, the James Webb Space Telescope has done it again. Astronomers have found what they're calling an 'impossible' atmosphere on a planet called TOI-561 b — a scorching, ancient, rocky super-Earth where a year lasts just over ten hours. Scientists expected it to be a bare rock, but Webb revealed the planet is far cooler than it should be, suggesting a thick atmosphere is distributing heat across its surface. Researchers think it may be a churning magma ocean beneath that atmosphere, and the planet might even be rich in volatile materials, earning it the nickname a 'wet lava ball.' Strange doesn't even begin to cover it.

And while we're looking for life out there, astronomers have narrowed down the most promising candidates. Out of more than 6,000 known exoplanets, researchers have identified just 45 rocky worlds most likely to support life. The study is even being compared to the sci-fi novel Project Hail Mary in terms of its spirit of searching. Forty-five worlds. That's our current shortlist for finding neighbors in the universe.

Back on Earth, let's talk about a hidden treasure sitting beneath one of America's most iconic landmarks. Scientists have discovered a massive freshwater reservoir hiding under the Great Salt Lake in Utah. Using airborne electromagnetic surveys, researchers found freshwater extending up to four kilometers below the lake's surface — far deeper than anyone expected. The discovery actually began when researchers noticed mysterious reed-covered mounds formed by pressurized groundwater pushing upward. Scientists are now exploring whether this underground water could help manage hazardous dust from the lake's shrinking, exposed lakebed. It's an unexpected lifeline hiding in plain sight.

Now, let's talk health. Scientists have identified a specific strain of 'good' bacteria in the respiratory tract that may help prevent long COVID. According to the WHO, around 400 million people worldwide have experienced long COVID. Understanding why some people develop it and others don't is one of medicine's most pressing questions, and the microbiome may hold important clues.

In another surprising health finding, researchers at Aarhus University are re-examining what they call a 'forgotten organ' — a small immune structure once thought to stop functioning early in adulthood. Their findings suggest it continues to influence cancer risk, cardiovascular disease, and how well patients respond to treatment. Sometimes the answers are hiding in the parts of biology we stopped paying attention to.

On the topic of cancer, there's genuinely exciting news about CAR-T cell therapy — a powerful treatment for certain blood cancers. Traditionally, it requires removing a patient's immune cells, shipping them to a lab for genetic modification, and then reinfusing them. It's complex, expensive, and time-consuming. But a new approach is reprogramming immune cells directly inside the body, potentially making this life-saving therapy faster, cheaper, and more widely accessible.

And there's a fascinating development in brain health. A new study points to an overlooked structure deep in the brain that may play a key role in maintaining physical strength as we age. Researchers believe it may be possible to identify and address frailty before it even develops by monitoring this brain region. The connection between brain activity and muscle strength is turning out to be more direct than we ever imagined.

In diet and dementia research, a long-term Swedish study has added a wrinkle to conventional wisdom. Older adults with a genetic predisposition to Alzheimer's disease did not show the expected increase in cognitive decline when they ate relatively high amounts of meat. The relationship between diet and dementia, it turns out, may be far more nuanced than simple dietary guidelines suggest.

On the weight loss front — and this one is genuinely wild — scientists studying pythons have found a natural molecule that triggers Ozempic-like weight loss effects. Pythons can consume prey equal to their own body weight and then go months without eating, all while maintaining metabolic efficiency. The molecule identified in their biology could point to entirely new approaches for treating obesity in humans. Nature, as always, got there first.

Moving to materials science, researchers have identified a new quantum mechanism that boosts energy transfer in nanomaterials. It turns out that proton motion — not just electron movement — can powerfully influence how energy is transferred at the nanoscale. This could have real implications for solar energy, medical devices, and advanced materials.

There's also a proposal to detect gravitational waves in a completely new way — using the light emitted by atoms rather than giant kilometer-scale detectors. This theoretical approach could open up an entirely new window on some of the most extreme events in the universe, like colliding black holes.

In archaeology and ancient DNA, a study of Argentina's Uspallata Valley reveals that farming was adopted by local hunter-gatherers rather than being introduced by outsiders. Centuries later, a stressed group of maize-heavy farmers migrated into the region facing climate instability, disease, and declining populations. Remarkably, there's no evidence of violence — instead, families used kinship networks to survive. Cooperation, not conflict, carried them through the crisis. That's a story worth remembering.

And finally, two stories with serious implications for our present and future. A new study warns that the global cobalt supply chain — absolutely critical for lithium-ion batteries and electric vehicles — is far more fragile than it appears, with risks of sudden, system-wide collapse. As the clean energy transition accelerates, the materials underpinning it are becoming geopolitical pressure points.

And in Brazil, scientists have found antibiotics accumulating in a major river, with a banned drug even detected inside fish sold for food. A common aquatic plant showed promise in filtering these chemicals out — but it also changed how fish absorb them, creating unexpected new risks. Antibiotic contamination in food systems is a growing global concern, and this study underscores just how complicated the solutions can be.

What a week in science. From the oldest art ever made to impossible alien atmospheres, from forgotten organs to python-inspired weight loss drugs — the pace of discovery right now is extraordinary. That's all for today's episode of Peer Review'd. If you enjoyed this episode, share it with someone curious, leave us a review, and we'll be back soon with more science that matters. Stay curious out there.