The Fornax Cluster The fall of galaxies towards galaxy clusters' centers is another cause of stars formation as such motions are bringing gases to be compressed. Galaxy clusters are themselves forming at the nodes of the vast filamentary web which makes the underlying structure of the Universe and they are enduring various internal motions. Such a view is well illustrated by a recent NASA Chandra X-ray Observatory at the Fornax cluster. The galaxies seen near the center of the picture -which is the center of the cluster too- are moving towards some others, unseen on this picture, located at the outskirts of the cluster at the lower right. Due to the motion, the gas cloud surrounding the group is taking a comet tail-shape (frame, X-ray view). The brightest point at the lower left of the bright central galaxy is another galaxy just orbiting the core's group and being stripped from its gas. Along orbits galaxies are thus deprived from their gas and star formation processes stop. The filamentary web along which clusters are forming is now thought to be composed of dark matter, gas, and galaxies. Dark matter, at the Fornax cluster, might be flowing to the common center of gravity of the two galaxy groups, adding to the motions and the star fabrics. The Fornax is a constellation of the southern hemisphere and the Fornax cluster is 65 million light-years away. picture © site 'Amateur Astronomy' based on pictures Pal.Obs. DSS (background) and NASA/CXC/Columbia U./C.Scharf et al. and (framed)