NASA explains that the low Earth orbit region of space is "the most concentrated area for orbital debris." NASA says of this image (and the following two pictures): The following graphics are computer generated images of objects in Earth orbit that are currently being tracked. Approximately 95% of the objects in this illustration are orbital debris, i.e., not functional satellites. The dots represent the current location of each item. The orbital debris dots are scaled according to the image size of the graphic to optimize their visibility and are not scaled to Earth. These images provide a good visualization of where the greatest orbital debris populations exist. Below are the graphics generated from different observation points.
NASA says of the image: The GEO Polar images are generated from a vantage point above the north pole, showing the concentrations of objects in LEO and in the geosynchronous region.