Astronomical surveys are systematic observations of celestial objects and phenomena, aimed at gathering data about the universe. These surveys can cover large areas of the sky and often utilize advanced telescopes and imaging technology to capture detailed information about stars, galaxies, and other cosmic entities. The data collected from astronomical surveys helps scientists understand the structure and evolution of the universe. Notable surveys include the Hubble Space Telescope survey and the Sloan Digital Sky Survey, which have provided invaluable insights into the distribution of dark matter and the formation of galaxies.