Largest ALMA Image Ever Captured Reveals Intricate Molecular Chemistry at the Milky Way’s Chaotic Core

Astronomers capture the largest ALMA image ever, mapping 650 light-years of the Milky Way’s core. See the filaments of gas feeding stars near the central black hole.

By: AXL Media

Published: Feb 26, 2026, 6:23 AM EST

Source: The information in this article was sourced from ESO/ALMA

A Panoramic View of Galactic Extremes

Astronomers have unveiled a landmark observation of the Milky Way’s center, revealing the "Central Molecular Zone" (CMZ) in unprecedented detail. Using the Atacama Large Millimeter/submillimeter Array (ALMA), the ACES project stitched together a mosaic as wide as three full Moons side-by-side. This 650-light-year expanse surrounds the supermassive black hole at our galaxy’s core, offering a unique laboratory to study the raw materials of star formation. Because the CMZ is the only galactic nucleus close enough to Earth for high-resolution study, it serves as a critical proxy for understanding the chaotic, high-density environments of the early universe.

The Molecular Fingerprints of the Core

The survey goes beyond mere visual mapping, unpacking the complex "hidden chemistry" of the galactic heart. By observing at millimeter wavelengths, ALMA detected a diverse array of molecules ranging from simple silicon monoxide to complex organic compounds like methanol, acetone, and ethanol. These molecules act as tracers, allowing scientists to visualize different physical conditions within the gas clouds. In the new imagery, specific colors represent distinct chemical signatures: sulphur monoxide appears in cyan, while cyanoacetylene is shown in blue, highlighting the varied chemical habitats that exist just light-years away from the central black hole.

Filaments Feeding the Stellar Giants

The ACES dataset reveals a highly filamentary structure where cold molecular gas flows along cosmic "veins" to feed dense clumps of matter. Within these clumps, some of the most massive stars in the Milky Way are born. Unlike the tranquil star-forming regions in the galaxy’s outskirts, the CMZ is a place of violent extremes where stars "live fast and die young." Many of these giants end their lives in hypernovae, explosions even more powerful than standard supernovae. The study aims to determine if our current theories of star formation—largely based on calmer regions of space—can withstand the turbulent pressures and magnetic forces found at the galactic center.