Two white papers posted on October 15, 2026, outline a route toward a more detailed chemical inventory of forming planetary systems. Their proposed ALMA2040 capabilities would help astronomers study the material available to rocky planets and search for rarer molecules in interstellar clouds. These are science cases for a future facility, not announcements of newly detected life or a completed upgrade.
Looking closer to a young star
In “Chemistry on solar system scales,” Catherine Walsh and colleagues focus on the small inner regions of planet-forming disks. Those regions help determine the ingredients of terrestrial worlds, yet faint molecular emission there is difficult to map with present instruments.
The team calls for roughly tenfold better spectral-line sensitivity and resolution corresponding to about five astronomical units or less at a distance of 140 parsecs. An astronomical unit is approximately the Earth–Sun distance. The objective is to move chemical mapping closer to the zones where rocky planets assemble, rather than concentrating on larger, easier-to-observe structures.
Water is a particular target. The paper examines how improved observations could probe material inside the water snowline, the boundary beyond which water freezes onto grains. It uses simulated observations to explore what the proposed instrument might reveal.
A broader molecular search
A companion white paper led by Víctor M. Rivilla considers chemical complexity across star- and planet-forming environments. Its authors note that more than 350 interstellar molecules are already known, while the full inventory remains uncertain.
They argue for broad frequency coverage and greater sensitivity so that several weak spectral transitions from a candidate molecule could be measured together. Those multiple lines matter: a convincing identification needs a consistent molecular fingerprint, rather than one suggestive feature in a crowded spectrum.
The proposed searches include molecular families relevant to prebiotic chemistry, such as amino acids, sugars and nucleobases. Establishing their distribution would address the availability of chemical ingredients. It would not, by itself, show that organisms use those ingredients anywhere beyond Earth.
Separate ambitions from work already under way
ALMA does have an existing modernization programme: the Wideband Sensitivity Upgrade. ESO describes that project as improvements to receivers, digital electronics, signal transport and the correlator, with observing bandwidth intended to double initially and eventually quadruple. The upgrade is part of the ALMA 2030 roadmap.
That established programme should not be confused with the larger capabilities explored in the new ALMA2040 papers. A technical requirement in a science proposal is not evidence that the equipment has been funded, built or scheduled for operation.
The papers’ immediate contribution is a clearer observing agenda: determine which measurements are missing, calculate the performance needed to obtain them, and connect chemical inventories to the formation of planets. Those steps can make the search for life’s raw materials more testable without turning a promising molecule into a claim of biology.
Generated illustration. Radio dishes and a conceptual planet-forming disk represent proposed observations of planetary chemistry. The disk is not a real object in the sky above ALMA.
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