Exoplanet TRAPPIST-1E in Habitable Zone, Black Death Volcanism Theory, and Sick Ants: NPR Shortwave Science Episode

Three science stories from NPR's Shortwave explore far‑flung questions and tiny behaviors: the possibility that the Earth-sized exoplanet TRAPPIST-1E lies in a habitable Goldilocks zone, whether ancient volcanic eruptions could have shaped the climate and crops that fueled the Black Death, and a surprising look at social insects where sick ants signal others to destroy them to protect the colony. The episode frames how new measurements and clever inferences push the boundaries of where life could exist, how climate perturbations may ripple through history, and how collective behavior in ants reveals new biological strategies for disease control. Together these segments highlight how discovery blends astronomy, history, and biology.

Exoplanet TRAPPIST-1E and the Habitable Zone

The episode begins with astronomy updates on exoplanets, focusing on TRAPPIST-1E, a rocky world similar in size to Earth that sits in the star’s habitable zone. Scientists explain why this zone is considered Goldilocks territory: not too hot for liquid water, not too cold for global ice. By analyzing the planet's atmosphere as it transits its star, researchers search for molecules like CO2 and methane, which could hint at atmospheric conditions conducive to life. The lead author emphasizes that TRAPPIST-1E offers the best chances to detect life if it exists there, underscoring how transit spectroscopy can reveal atmospheric fingerprints. “we have the best chances of detecting it if it's present on TRAPPIST-1E.” - Sukhrit Ranjan

These findings are framed alongside broader questions about Titan-like exotitans and the challenges of confirming atmospheres around distant worlds. The discussion underscores how improvements in telescope technology and observational methods shape our understanding of where life could thrive beyond the solar system.

Black Death and Volcanoes: A Climate Connection?

The narrative shifts to a medieval mystery: the Black Death that swept through Europe in the 14th century. The hosts recount the prevailing bacterial cause linked to fleas on rodents, but then introduce a provocative volcanic hypothesis. A scientist proposes that a major eruption years earlier injected sulfate aerosols into the atmosphere, potentially triggering climate disruptions that contributed to crop failures and food shortages, which in turn affected grain transport and rat populations. Evidence drawn from tree rings and ice cores is discussed, suggesting climate downturns linked to volcanic activity could have cascaded into one of history’s deadliest pandemics. The host summarizes the cautious nature of the claim, noting that this remains a hypothesis requiring more data and better records from centuries past. “volcanic activity in 1345 led to extreme rainfall.” - Martin Bach

Sick Ants: Self-Sacrifice for Colony Health

The final segment turns to the insect world, reporting on a Nature Communications study about sick pupae signaling their illness to worker ants. The workers respond by removing and disinfecting the infected pupae with formic acid, a process that can save the colony by curbing fungal spread. The researchers explain the sequence: pupae exposed to infection emit chemical cues, workers peel the cocoon, bite the pupae, and spray disinfectant. An intriguing twist reveals that queen pupae—destined to become future queens—do not emit these signals, and can resist infection, suggesting a division of labor and risk tolerance within ant colonies. “the queen pupae didn't release the signal even when they were infected.” - Erica Dawson

Across these segments, the episode demonstrates how astrophysical observations, historical climate data, and animal behavior converge to illuminate big questions about life, disease, and resilience in complex systems.