Dark matter has puzzled scientists for decades, and each day more evidence of its existence is discovered. According to a report from Sci-News, astronomers from Stony Brook University have found 854 ultra-diffuse galaxies (UDGs) after examining the Coma cluster, about 300 million light years away, using the Subaru telescope in Hawaii. Many of the galaxies are roughly the size of the Milky Way, and are believed to be full of dark matter.

The galaxies are situated around a central point, which suggests that the majority are members of the same cluster. According to the authors of the study, the galaxies show no sign of H-alpha emission, whichmeans that they stopped making new stars some time ago. Despite their similar size to the Milky Way, many of these UDGs contain only 1/1000 of the stars that our home galaxy does.

Scientists think that although these galaxies look sparse, they are probably filled with dark matter. Dr. Jin Koda, the lead author of the study, explains that despite how diluted the galaxies appear, “they are very likely enveloped by something massive.”

Visible matter makes up less than one percent of the galaxies’ mass, which is extremely low compared to other galaxies. The UDGs may help give scientists insight into what occurs near the end of a galaxy’s life.

There are still many questions to be answered about the strange galaxies. Do all galaxy clusters contain dark matter? When were they formed, and when did they exhaust all of their star-forming fuel? The astronomers plan to conduct follow-up spectroscopic studies in the near future to look for more clues about the mysterious galaxies.