The most empty regions of the universe are voids. Which one is the largest is debated.
The universe consists of filaments where most galaxies and dark matter can be found. They have recently been found to rotate, and galaxies in them are slowly moving towards places where they meet with other filaments. These confluences are home to the most massive superclusters of galaxies, and the Milky Way, together with the nearby other galaxies, is moving towards one called the Shapley Attractor.
In between the filaments, there are voids. They are not empty but contain stars and even some galaxies. The largest known one is the Giant Void, which is 1 to 1.3 billion light-years across. The famous Boötes Void is only a third to a quarter as large.
There are other candidates for the largest voids in the universe. The Eridanus Supervoid associated with a cold spot identified in cosmic microwave background relic radiation might be even up to 1.8 billion light-years across.
Surprisingly, the Milky Way, Andromeda Galaxy, and their satellites might be part of an even larger underdensity called the KBC Void or the Local Hole. It might be between 600 million and 2 billion light-years across. If it turns out to be at the higher end of these estimates, then this will be the emptiest region of the visible universe.
The question was: What is the most empty region in the Universe
Post a Comment