Science Snapshots: October 25, 2026

A July dawn that may have inspired ‘Starry Night’

Art historians have debated whether Vincent van Gogh’s ‘The Starry Night’ painting depicts an actual sky. The painting has been dated to mid-June 1889 but the sky then does not match the real sky of that period. Using astronomical simulations, view reconstructions, historical weather data, and Van Gogh’s correspondence, researchers have now found the painting closely matches the dawn sky on around July 22, 1889, with the celestial canvas nearly mirroring Van Gogh’s view from Saint-Rémy.

Link between moderate cold and lifespan explained

Why do moderately cold temperatures prolong lifespan? Using the nematode Caenorhabditis elegans, scientists found cold exposure stimulates muscle cells to produce the metabolite BH2, which travels to intestines and neurons, where a salvage enzyme converts it to BH4. BH4 then drives tyrosine synthesis via the enzyme PAH-1, extending lifespan. Boosting BH2 production in muscles alone could extend lifespan. Treating patient-derived motor neurons with BH2 also prevented toxic protein aggregation linked to Huntington’s disease and amyotrophic lateral sclerosis.

Placing similar buildings together can cool cities

Grouping buildings with similar functions, such as schools and houses, into larger clusters can cool cities, a study has found. Using a metric to measure the continuous size of such clusters in 101 cities, scientists found larger clusters correlate with lower surface heat. Every 100-m increase in cluster scale reduces urban heat island intensity by 4.5% because buildings with similar functions have comparable shapes and operating schedules, allowing for better airflow and coordinated heat release.