Dark matter clouds do not directly block out stars or prevent their formation. Dark matter, by its nature, does not interact with light or other electromagnetic radiation, so it does not have a direct effect on the visibility of stars. However, the gravitational influence of dark matter can indirectly affect the distribution of stars within galaxies and galaxy clusters.
Dark matter's gravitational pull can act as an attractive force, causing normal matter, including gas and dust, to gather and condense in certain regions. These regions, where normal matter accumulates, are potential sites for star formation. As the gas and dust collapse under gravity, they can form dense regions called molecular clouds, which are the birthplaces of stars.
The distribution of dark matter and normal matter is not always perfectly aligned. While dark matter is thought to be more uniformly distributed on larger scales, normal matter can experience additional forces and interactions, such as pressure from gas and radiation, which can affect its distribution. Therefore, there can be some spatial separation between regions rich in dark matter and regions rich in normal matter, including stars.
It's important to note that dark matter itself does not contain stars or emit light. It primarily influences the motion and distribution of normal matter, including stars, through its gravitational effects. This is why we observe stars primarily in regions where normal matter is more concentrated, such as the visible parts of galaxies, while dark matter remains largely invisible and inferred from its gravitational influence on visible matter.
The complex interplay between dark matter and normal matter is an active area of research in astrophysics, and scientists use various observational and theoretical approaches to study their relationship and understand the formation and evolution of galaxies and galaxy clusters.