Observing How the Universe Changed over Time

The distribution and concentration of matter in the Universe for sizes larger than a galaxy is called the large-scale structure of the Universe. Astronomers can use the location and distance to billions of galaxies observed by Rubin Observatory to create a map that reveals this large-scale structure.

Here is a series of maps that show the galaxies detected by Rubin Observatory at certain distances away from Earth (expressed as redshift numbers). Lower redshift numbers correspond with distances that are closer to Earth, and higher redshift numbers correspond with distances that are farther. Each map can be thought of as a slice in time from the history of the Universe—at greater distances we see the Universe as it was at earlier times. The axes of the maps (RA and Dec) show the position of these galaxies as viewed from Earth.

Select the redshift that corresponds with the earliest time, and then move through the maps to see how the Universe has changed over time.