A team of astronomers led by Christopher Conselice at the University of Nottingham in the UK have been studying the deep field images coming from the Hubble Space Telescope and concluded that the Universe contains ten times as many galaxies as was previously thought.
The previous census performed by the Sloan Digital Sky Survey, SDSS (link below) concluded that the observable Universe contained between 100-200 Billion galaxies.
This new census realized that the density of galaxies in the early Universe was far greater than it is now and that many of these early galaxies were too faint to be seen in the data used by the SDSS. On the basis of their data from the Hubble they have realized that the Universe contains on the order of one Trillion galaxies.
As exciting as this discovery is it’s really nothing new. Every time we study the Universe with new, more powerful, more precise instruments the Universe grows ever larger. Sometimes the expansion is linear as with this census by Dr. Conselice and his team, sometimes it is exponential as when Carl Hubble himself discovered that the smudgy nebula he studied were actual galaxies separate from our Milky Way. By the way, the Greek word galaxy just means Milky Way. From Galileo to Dr. Conselice we have learned that the Universe is more than we can ever imagine.
I have seen this phenomenon of expansion happen three or four times now in my life and I expect to see it happen at least one more time.The James Webb space telescope is expected to be launched sometime in 2018 and with this new window to infinity I have no doubt that the Universe will grow once again.
To read further about the new census follow in link below.
http://www.spacetelescope.org/news/heic1620/