Galaxies like our Milky Way are not randomly distributed in space. Instead, they are grouped into groups, groups, and weak giant groupings. They were created over billions of years under the influence of the gravity of dark matter and the repulsive influence of dark energy. So anyone who studies the evolution of the large-scale structure of the universe in detail will learn a lot about these mysterious components of the universe.
In late May, astronomers released new results from the Dark Energy Survey (conducted with a giant digital camera on a large telescope in Chile), based on measurements of 226 million galaxies. To determine the distances of all these galaxies, a fairly approximate method was used, based on the observed colors.
The new DESI survey (DESI stands for Dark Energy Survey Tool) that began in mid-May takes the matter even more extensively. DESI is an array of large and sensitive spectrophotometers on the 4-meter Mayall Telescope at Kit Peak Observatory in Arizona. This will accurately determine the distances of 35 million galaxies over the next five years. This puts an accurate 3D map of the universe at hand. The European space telescope Euclid, scheduled to launch at the end of 2022, goes further. Euclid should eventually provide data on about two billion galaxies. The hope is that the life path of the universe will collapse completely.
Brown: NOIRLab, Arizona, VS