Free Astronomy Magazine January-February 2026

JANUARY-FEBRUARY 2026 T he discovery of ancient water in a planet-forming disk reveals that some of the water found in com- ets—and maybe even Earth—is older than the disk’s star itself, offering breakthrough First-ever detection of “heavy water” in a planet-forming disk by NRAO T he above artist’s impression shows the evolution of heavy water mole- cules (H 2 O, HDO, and D 2 O) as they have been observed in giant molecu- lar clouds, a planet forming-disk, and comets—before they eventually may have made their way to Earth. [NSF/AUI/NSF NRAO/P. Vosteen, B. Saxton]