Cosmologists have merged the two largest Type Ia supernova collections into a single 2,884 strong sample, and the combined data once again hint that dark energy may be changing over cosmic time rather than holding steady. Elsewhere this week, Hubble and Webb teamed up to catch 27 of the smallest icy bodies ever seen beyond Neptune, spectroscopy of the plasma tail of 3I/ATLAS pointed to an extraordinarily cold birthplace around another star, and JWST set the tightest limit yet on moons orbiting an exoplanet. Four quiet results, four small corrections to the picture.

Chemists have found an answer as to why astronomers observe comets with green heads, but no green tails.

A new study establishes the link between rare, long-period comets coming from the outskirts of the Solar System and observable meteor showers.