What is the Boötes Void?
The Boötes void is the largest void in the known universe. It is a region 250 million light-years across, located in the direction of the constellation Boötes, which only contains a few dozen galaxies strewn in a rough tube shape through the middle. The Boötes void is so huge that its diameter is a whole 2% of the diameter of the observable universe. Discovered in 1981 by Robert Kirshner, Paul Schechter, Augustus Oemler Jr, and Stephen Shectman during a survey of galactic redshifts, the Boötes void is one of the first large voids discovered and is hence the most famous. Voids of this size are often referred to as supervoids. The Boötes void is home to regions that probably have the lowest particle densities in the entire observable universe. Though the average particle density in the universe is estimated to be about one particle per cubic feet, the central regions of the Boötes void probably have particle densities several times lower than that. It is not known what quantities of dark
