The Great Wall is an enormous structure of galaxies, clusters, and superclusters that forms one of the largest known features in the universe. First discovered in the CfA Redshift Survey in 1989, it stretches over roughly 500 million light-years in length, making it a colossal filament of the cosmic web. Its width and thickness are smaller in comparison but still immense, highlighting the hierarchical and filamentary nature of large-scale cosmic structures.
The Great Wall is composed of dense clusters and galaxy groups connected along a continuous filament, with vast cosmic voids surrounding it. It demonstrates how matter in the universe is non-uniformly distributed, concentrating in massive threads and walls while leaving large empty regions in between. The structure’s formation is explained by gravitational collapse along primordial density fluctuations, with dark matter providing the invisible framework for galaxies to accumulate.
Studying the Great Wall helps astronomers understand the dynamics of superclusters, the flow of galaxies, and the large-scale geometry of the universe. It also provides insights into how such enormous structures can exist within the framework of cosmological models like ΛCDM, and challenges simulations to reproduce features of this scale accurately.
In essence, the Great Wall is a gigantic, thread-like assembly of galaxies, one of the universe’s largest structures, illustrating the cosmic web’s vast and interconnected architecture.