Little Red Dots and the Black Hole “Cocoon Phase”: JWST’s “Little Red Dots” are infrared-bright sources seen when the universe was about 1 billion years old. Their broad emission lines first suggested gas racing at thousands of km/s, implying black holes that were “overmassive”—10–100% of their host galaxies’ mass. A new Nature study led by Vadim Rusakov argues the widths are an optical trick. The team models the triangular line profiles as Thomson scattering in a dense cocoon of free electrons that broadens otherwise narrow lines. With scattering accounted for, intrinsic gas speeds drop and black-hole masses shrink by ~100×, to roughly 10–100 million solar masses—closer to normal galaxy/black-hole ratios. The same cocoon can absorb X-rays, explaining why Chandra sees little; what remains is pinning down how long and how common this phase is. (Ars Technica)

Wearables Reveal the Real “Minimum Dose” of Exercise: Wearable data are redefining how much exercise is needed for health. Guidelines recommend 150–300 minutes of moderate activity weekly (or 75–150 vigorous) plus muscle strengthening, but device-based studies show benefits begin well below those targets. Large cohorts find risk drops fastest when people move from “none” to “some,” with diminishing returns at higher volumes. One long-term analysis linked 20–74 minutes of moderate activity per week to a 9% lower all-cause mortality risk, and 150–300 minutes to about a 20–21% reduction. Brief “exercise snacks” can count: 1–2 minute bursts of vigorous intermittent lifestyle activity, repeated a few times daily, were associated with big mortality reductions in non-exercisers. Wearables also spotlight sedentary time as a separate hazard, encouraging a 24-hour approach: move more, sit less, sleep well. (Nature)

How Greenland Sharks Defy Aging: Greenland sharks can live for centuries, and new work is teasing apart the “maintenance tricks” that keep key tissues functioning over extraordinary spans of time. Science News reports that researchers examined eye tissue from 10 sharks (some estimated to be ~150 years old) and found molecular and cellular features consistent with vision in dim Arctic waters, plus signs the eyes avoid typical age-related wear—potentially helped by elevated DNA-repair activity. But the story also highlights an apparent contrast: a separate team’s dissections suggest the sharks’ hearts do accumulate scarring and cellular damage with age, yet still function—hinting at unusual resilience mechanisms that may buffer organ performance despite chronic injury. Together, the findings sharpen the distinction between “repair,” “damage tolerance,” and true anti-aging biology. (Science News)

Trauma Exposure Is Linked to “Older” Biological Aging Profiles: An open-access GeroScience study analyzed UK Biobank data from 152,863 adults (mean age 56.4) to test whether lifetime exposure to non-relational trauma (e.g., serious accidents, war, life-threatening illness) correlates with multiple biological aging markers. The authors report that trauma exposure is associated with a metabolite-predicted age exceeding chronological age (MileAge delta), higher metabolomic mortality profile scores, and higher frailty—showing graded patterns with greater trauma burden, especially for frailty. By contrast, they find no evidence of an association with leukocyte telomere length and mixed findings for grip strength. All trauma types were linked to greater frailty, with the strongest association for life-threatening illness, and some effects differed by sex (e.g., trauma burden more strongly tied to frailty in females). (Springer)

A “Senescence Switch” in Tumors Tied to STAT1 and NFκB Signatures: A new GeroScience paper focuses on cytokine-induced senescence inside tumors, reporting that sustained activation of STAT1- and NFκB-dependent gene regulatory signatures underpins this senescent state. While senescence is often framed as a double-edged sword—halting proliferation but potentially reshaping tissue environments—this work emphasizes the transcriptional logic that appears to lock cytokine-driven senescence in place. The study’s framing matters for longevity science because cellular senescence is a core aging hallmark and a major therapeutic target (senolytics, senomorphics, immune-based clearance). By specifying the regulatory programs implicated here, the results point toward more precise strategies: instead of treating “senescence” as one thing, interventions could be tailored to the upstream signaling context (cytokine-driven vs. damage-driven) and the downstream gene programs that maintain it. (GeoScience)

NASA’s Juno Pins Down Europa’s Ice Shell Thickness: NASA reports that Juno’s Microwave Radiometer (MWR) has provided a new measurement of Europa’s ice shell: about 18 miles (29 km) thick in the region observed during Juno’s Sept. 29, 2022 flyby. The key advance is discrimination between thin- and thick-shell models that previously ranged from under half a mile to tens of miles. The article explains MWR’s “peek beneath the ice” approach—using microwave signals to infer temperatures at depth—and notes that the 18-mile estimate applies to the cold, rigid, conductive outer layer of (largely) water ice, with caveats: a warmer convective layer could mean thicker total ice, while modest salt could reduce the estimate by ~3 miles. Juno also inferred small “scatterers” (cracks/pores/voids) extending hundreds of feet, likely not major nutrient pathways. (NASA)

A Black Hole “Feeding Frenzy” May Explain JWST’s Early-Universe Mystery: Space.com covers new simulation work aimed at a JWST-driven puzzle: supermassive black holes appearing when the universe was under 1 billion years old—too early for standard growth-by-mergers and steady accretion. The researchers argue that chaotic, dense, gas-rich conditions in the first galaxies could trigger brief “feeding frenzies” in which early black holes grow via super-Eddington accretion—temporarily exceeding the Eddington limit that normally self-regulates inflow by radiation pressure. In simulations, first-generation black holes can balloon to tens of thousands of solar masses in a few hundred million years, providing a critical “head start” toward later supermassive scales. The piece links this to JWST’s “Little Red Dots” and suggests future gravitational-wave observatories (notably LISA) could test the merger-heavy implications of this pathway. (space.com)

‘Dark Oxygen’ Returns: Scientists Launch Deep-Sea Tests to Confirm a Sunless Source: Researchers are mounting a new push to verify and explain “dark oxygen” — unexpectedly large amounts of O₂ detected about 4,000 meters down in the Pacific, far below depths where sunlight could drive photosynthesis. The phenomenon was first reported in 2024 in Nature Geoscience, and now the same team is deploying purpose-built seafloor landers and high-pressure lab setups to test whether oxygen is being produced in situ. Backed by a $5.2 million Nippon Foundation grant, scientists plan a May expedition to the Clarion–Clipperton Zone aboard the Nautilus. New probes will add pH sensors to look for signatures of water splitting, and experiments will probe whether polymetallic nodules catalyze electrochemical reactions or whether microbes contribute—or both. The work also intersects with seabed-mining debates, as the original observations came from mining-impact studies and remain contested. (Nature)