An international team of astronomers led by University of Nottingham scientist Christopher Conselice has performed an accurate census of the number of galaxies in the observable Universe. They came to the conclusion that the Universe contains at least two trillion galaxies, nearly ten times as many as previously thought.
Prof. Christopher and his colleagues from Leiden Observatory in the Netherlands and the Universities of Nottingham and Edinburgh in the UK reached this conclusion using images and other data from NASA’s Great Observatories (Spitzer, Hubble, and Chandra), ESA’s Herschel and XMM-Newton space telescopes.
The scientists painstakingly converted the images into 3D, in order to make accurate measurements of the number of galaxies at different times in the Universe’s history.
In addition, they used new mathematical models which allowed them to infer the existence of galaxies which the current generation of telescopes cannot observe.
This led to the surprising realization that in order for the numbers to add up, some 90% of the galaxies in the observable Universe are actually too faint and too far away to be seen — yet.