Unveiling the Boötes Void: The Great Nothing in Space

The Boötes Void, often referred to as ‘The Great Nothing,’ is a colossal, nearly spherical vacuum in space, home to a minimal number of galaxies. Nestled in the vicinity of the Boötes constellation—its namesake—its center is calculated to be at roughly 14h 50m right ascension and a declination of 46°. With an estimated diameter of nearly 330 million light-years—constituting approximately 0.27% of the observable Universe’s diameter—or a volume of almost 236,000 Mpc3, the Boötes Void is recognized as a ‘supervoid,’ making it one of the Universe’s largest known voids.

Its existence was first reported by Robert Kirshner et al. in 1981 during a galactic redshifts survey, with the void’s center located approximately 700 million light-years from Earth. Further investigations revealed the presence of galaxies within the void. Between 1987 and 1997, various astronomers, including J. Moody, G. MacAlpine, S. Gregory, M. Strauss, John Huchra, Greg Aldering, G. Bothun, and Ron Marzke, discovered a total of 60 galaxies residing in the void.

Greg Aldering, an astronomer, pointed out that the void’s scale is so vast that “If the Milky Way had been in the center of the Boötes Void, our awareness of other galaxies wouldn’t have occurred until the 1960s.” The Hercules Supercluster forms part of the void’s edge. Based on a rough estimate of approximately 1 galaxy every 10 million light-years, it’s likely that around 2,000 galaxies exist within the Boötes Void.