Mapping the Universe - Mapping Scientific Frontiers: The Quest for Knowledge Visualization - page 71

Fig. 2.23 Part of the rectangular logarithmic map of the universe depicting major astronomical
objects beyond 100 mpc from the Earth (The full map is available at http://www.astro.princeton.
edu/universe/all100.gif . Reprinted from Gott et al. 2005 )
the design. The scale is logarithmically transformed to compress the large amount of
voids in space into a compact map. The Earth is at the center of the map because the
SDSS telescope located on the Earth is used to measure the distance an astronomical
object is from us. Quasars, for example, formed in the early stages of the universe,
appear near to the outer rim of the circular map. Each red dot in the outer belt depicts
a quasar found by the SDSS survey.
The map conveys 14 types of information, including various astronomical objects
such as high redshift quasars found by SDSS, extrasolar planets, stars, and space
probes. In addition to astronomical objects found by the SDSS survey, the circular
map of the universe contains the positions of several other types of objects such
as galaxies found by the CfA2 survey, galaxies on the Messier catalog, and the
brightest stars in the sky. Some of the objects are associated with information about
when they were discovered and the time periods in which articles about these objects
attracted bursts of citations. Figure 2.26 shows the types of objects on the map, the
sub-total of each type of objects, and examples.