The second data release of the Dark Energy Camera Plane Survey, or DECaPS2, focuses on the galactic plane, which is the view looking across the disk of the galaxy in which most of the stars are located and covers 6.5% of the night sky.
The galactic plane is difficult to image because there are so many stars, which can overlap when seen from Earth, and because there is a lot of dust, which you can see as the dark swirls in the image above and which can obscure stars behind it. So the survey looked in near-infrared wavelengths which can peer through the dust for a better view, to build up a 3D view of the galaxy.
The total number of objects visible in the dataset numbers 3.32 billion, and is the result of 10 terabytes of data from 21,400 individual exposures taken using the Dark Energy Camera in Chile.