Hubble Discovers ‘Cloud-9’: Rare Failed Galaxy Discovery
- Astronomers using the Hubble Space Telescope have just spotted a new type of celestial object: cloud-9, a starless, gas-rich cloud of dark matter that was slightly too light...
- 10 in The astrophysical Journal Letters adn presented this week at the 247th meeting of the American Astronomical Society in Phoenix, this odd object is located more than...
- As an inevitable result,the discovery of Cloud-9 strongly supports a cornerstone of the leading cosmological framework that aims to explain the structure and composition of the universe -...
Astronomers using the Hubble Space Telescope have just spotted a new type of celestial object: cloud-9, a starless, gas-rich cloud of dark matter that was slightly too light to become a full-fledged galaxy.
As detailed in a study published Nov. 10 in The astrophysical Journal Letters adn presented this week at the 247th meeting of the American Astronomical Society in Phoenix, this odd object is located more than 14 million light-years from Earth, near the spiral galaxy Messier 94 (M94). Cloud-9 is a cosmic relic, a primordial building block of galaxies that confirms the critical mass threshold needed for a body of gas and dark matter to collapse into a galaxy.
As an inevitable result,the discovery of Cloud-9 strongly supports a cornerstone of the leading cosmological framework that aims to explain the structure and composition of the universe - the Lambda cold dark matter model (LCDM). One of the model’s major predictions is that dark matter settles in halos, which may or may not grow heavy enough to anchor galaxies.
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But, as described in the new study, a follow-up with the Hubble Space Telescope’s Advanced Camera for Surveys revealed a much rarer phenomenon, one that astronomers had been seeking for years: a “theoretical phantom object” and the first-ever confirmed RELHIC, or Reionization-Limited H I Cloud. In other words, a cloud of neutral hydrogen, a natal leftover from the early cosmos and a unique “window into the dark universe,” Fox said in a NASA press statement.
This hydrogen detection was proof that Cloud-9 was not a typical dwarf galaxy, but something stranger.
Dark Matter: An Overview
Dark matter is a hypothetical form of matter that accounts for approximately 85% of the matter in the universe and about 27% of the total mass-energy density. Its existence is inferred from gravitational effects on visible matter, such as the rotation curves of galaxies and the gravitational lensing of light.
The concept of dark matter arose in the 1930s when astronomer Fritz Zwicky observed that galaxies within the Coma Cluster were moving faster than expected based on the visible mass alone. The European Space Agency (ESA) explains that this discrepancy suggested the presence of unseen mass contributing to the cluster’s gravity.
Such as, observations of the bullet Cluster, a collision of two galaxy clusters, provide strong evidence for dark matter. The dark matter passed through the collision relatively undisturbed, while the hot gas (visible matter) interacted and slowed down, demonstrating that dark matter does not interact with itself or ordinary matter through forces other than gravity. NASA’s Chandra X-ray Observatory provides detailed images and analysis of the Bullet Cluster.
Dark Energy and its Relationship to Dark Matter
Dark energy is a mysterious force that makes up about 68% of the universe’s total energy density and is responsible for the accelerating expansion of the universe. While distinct from dark matter, both contribute to the fact that ordinary matter only accounts for about 5% of the universe’s total composition.
The discovery of dark energy in the late 1990s, based on observations of distant supernovae, revolutionized cosmology. The 2011 Nobel Prize in Physics was awarded to Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess for their discovery of the accelerating expansion of the universe.
Specifically, observations of Type Ia supernovae, which have a known intrinsic brightness, revealed that these supernovae were fainter than expected at their measured redshifts, indicating they were farther away than predicted by a constant expansion rate. This led to the conclusion that the expansion of the universe is accelerating, driven by dark energy.
Current Research and Detection Efforts
Scientists are actively searching for direct and indirect evidence of dark matter particles. Direct detection experiments aim to observe dark matter particles interacting with ordinary matter in underground laboratories, shielded from cosmic rays. Indirect detection experiments search for the products of dark matter annihilation or decay, such as gamma rays, cosmic rays, and neutrinos.
The XENON1T experiment,located in Italy’s Gran Sasso National Laboratory,is one such direct detection experiment. In 2020, the XENON1T collaboration reported an excess of events that could possibly be interpreted as a dark matter signal, although further examination is needed to confirm this finding. As of January 9,2026,no definitive detection of dark matter has been confirmed.
Furthermore,the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST), currently under construction in Chile, is expected to provide a wealth of data that will help constrain the properties of dark matter and dark energy through gravitational lensing studies and other cosmological probes.First light is anticipated in 2024.