In January 2024, the Subaru Telescope, an optical telescope in Hawaii, captured images of dark matter extending millions of light-years from the latter galaxy cluster, the first time a network of dark matter has been detected on such a scale. 
Dark matter is a theoretically proposed invisible matter that may exist in the universe, it does not emit light or absorb light, it is transparent to light, and there are almost no interactions outside of gravity, so it cannot be directly observed. However, through astronomical observations and the study of cosmological models, scientists have discovered that dark matter may be the main component of cosmic matter, accounting for 26 percent of the total mass energy of the universe8% or so, which has had an important impact on the structure and evolution of the universe.
So far, human beings have not figured out the basic properties of dark matter, and in some science fiction**, dark matter will be imagined as space or parallel worlds in other dimensions.
The discovery is the Subaru Telescope's ultra-wide-angle fixed-focus camera, which combines high sensitivity, high resolution, and a wide field of view to capture the emergence of dark matter extending from galaxy clusters, which extends over millions of light-years, clearly indicating that this structure is part of the cosmic web.
Above is the optical telescope capture process**, the green part is the distribution of dark matter detected in the region of the later galaxy cluster, and the background is the image taken with HSC. The research team studied the distribution of dark matter by precisely measuring the effect of the slight distortion of the shape of galaxies due to the presence of dark matter (weak gravitational lensing effect) taken by HSC. Dark matter can be seen extending radially from the center of the galaxy cluster (the center of the image).
By exploring the nature and composition of dark matter, humans can discover new elementary particles and physical phenomena and advance physics.