NASA’s Hubble Space Telescope confirmed a starless object called Cloud-9. It is the first known Reionization-Limited H I Cloud, or RELHIC.
This cloud consists mostly of neutral hydrogen gas. Dark matter controls most of it. The object dates back to early galaxy formation.
Cloud-9 lies about 14 million light-years from Earth. It sits close to the spiral galaxy Messier 94, or M94. China’s FAST telescope first spotted it three years ago in a radio survey.
NASA shared on X January 5, 2025, that Hubble helped detect this new object. Cloud-9 is a starless cloud full of gas and dark matter. It reveals clues about dark matter and the early universe.
The Green Bank Telescope and U.S. Very Large Array later verified it. High-detail radio scans showed small twists in the gas. These point to contact with M94.
The cloud’s core holds neutral hydrogen. It spans roughly 4,900 light-years across, NASA reports.
Radio measurements put the gas mass at one million Suns. Gas pressure versus gravity suggests five billion Suns of dark matter.
Hubble images from its Advanced Camera for Surveys prove key facts. No stars appear inside Cloud-9’s edges. Only distant background galaxies show up.
This lack of stars sets it apart from dwarf galaxies. It seals Cloud-9’s status as a RELHIC. These are ancient clumps with too little gas to form stars.
Cloud-9 differs from large hydrogen clouds near the Milky Way. It stays small, round, and tight. Early universe rules let dark matter halos trap hydrogen without sparking stars.
Such objects now face tough odds. Space motion strips gas through ram pressure. Bright nearby lights hide them from view. Cloud-9 marks the ninth gas cloud near M94.
The find matches models of dark matter clumps. These act as failed galaxies. NASA expects more RELHIC hunts. They will sharpen views on galaxy birth and dark matter traits.
Results appear in The Astrophysical Journal Letters. Scientists shared them at the American Astronomical Society’s 247th meeting. Hubble teams up NASA and the European Space Agency. It has run over 30 years. NASA’s Goddard Space Flight Center handles daily work. The Space Telescope Science Institute leads research.
