This Week in Science: Flight Crews Face Highest Radiation Risk, a Galactic Speedster, Jellyfish vs. Reactors, and More

Welcome to This Week in Science — a roundup of striking research and notable events from the world of science. This edition covers an occupational study that flags flight attendants as having the highest share of radiation‑related cancer deaths, a record‑setting object orbiting our galaxy’s central black hole, fresh links between daily sugary drinks and stomach cancer, jellyfish repeatedly disabling a French reactor, lab‑grown brain organoids that track time, and technical barriers to burning hydrogen in existing turbines.

Flight Crews Top Occupational Radiation Risk

Researchers who analyzed data across more than 500 occupations report that flight attendants account for the largest proportion of radiation‑related cancer deaths, with pilots ranking second. The most likely explanation is increased exposure to cosmic radiation at typical cruising altitudes: the atmosphere provides substantially less shielding from high‑energy particles at flight levels than at ground level, so aircrew accumulate higher doses over time.

A Galactic Speedster: S301 Around Sagittarius A*

Astronomers studying the Milky Way’s crowded center have identified an extraordinary object named S301 orbiting near Sagittarius A* — the Galaxy’s supermassive black hole (~4.3 million solar masses). S301 follows an 8.7‑year orbit and achieves speeds exceeding 25,000 km/s (about 15,500 miles/s) at closest approach, coming as close as the distance between Saturn and the Sun. The discovery, reported in Nature, reveals extreme, compact orbits that test our understanding of dynamics in the galactic core.

Daily Sugary Drinks Linked To Higher Stomach Cancer Risk

New analysis published in Gastro Hep Advances suggests that people who drink at least one sugar‑sweetened beverage per day have an elevated risk of stomach cancer: roughly a 2.45‑fold increase compared with never‑drinkers. With many adults and children consuming sugary drinks regularly, the study adds to growing evidence of diet‑related cancer risks and underscores the importance of public health guidance on sugar consumption.

Jellyfish Twice Force Reactor Shutdowns

In northern France, jellyfish clogged cooling intakes and forced the shutdown of a nuclear reactor — an event that reportedly occurred on the same calendar date two years running. While the animals aren’t taking a side in energy policy, the incidents highlight how biological and environmental phenomena can unexpectedly disrupt critical infrastructure and the need to design systems resilient to such events.

Lab‑Grown Mini‑Brains Encode Developmental Time

Scientists working with brain organoids — miniature, lab‑grown assemblies of neural tissue — report that these structures can ‘sense’ the passage of time and retain a cellular memory of how long they have been developing. Described in Nature, the finding offers a new experimental tool for probing developmental timing, maturation processes, and the cellular states that emerge as neural tissue forms outside the skull.

Gas Turbines Aren’t Ready For Hydrogen Yet

A multinational team publishing in Nature Materials warns that most existing gas turbines are not yet suitable to run on hydrogen without substantial redesign. Although hydrogen promises low‑carbon energy when produced from renewables, widespread adoption faces challenges beyond production — including material compatibility, combustion stability, and retrofit feasibility for current infrastructure.

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ScienceAlert stories are written, fact‑checked, and edited by humans. This summary synthesizes recent reporting and peer‑reviewed studies.