Number of Galaxies in the Universe 10 Times More Than Previously Thought
A new study reveals that the number of observable galaxies in the universe is about 10 times more than previously thought.
NASA previously estimated the total number of observable galaxies in the universe to be around 200 billion. However, a study published in The Astrophysical Journal showed that the total number of observable galaxies in the universe is actually a lot higher, around two trillion. Furthermore, the study also suggests that about 90 percent of the observable galaxies are too faint or too far away to be studied with the equipments we have today.
"It boggles the mind that over 90 percent of the galaxies in the universe have yet to be studied. Who knows what interesting properties we will find when we discover these galaxies with future generations of telescopes," said lead author of the study Christopher Conselice of the University of Nottingham, U.K, in a statement.
Previous estimates of the total number of observable galaxies in the universe are solely base on the Hubble Deep Field images takes in mid 1990s. Astronomers aimed Hubble at one section of the sky for ten days and created an image that NASA called to be "mankind's deepest, most detailed optical view of the universe." Basing on this observation, the astronomers concluded that the universe is composed of about 200 billion galaxies.
For the present study, deep-space images from Hubble were used as well. However, astronomers have other deep space data that have been published at their disposal to create a 3-D image of the observable galaxies in the universe. Base on their new analysis, the astronomers put the number of observable galaxies at two trillion.
Astronomers noted that some of the observable galaxies are too faint or too far away to be captured by Hubble alone. This is the reason why the new estimate is way higher than previous estimates 20 years ago.
With this findings, the astronomers are now excited for the launch of James Webb Space Telescope in 2018. The telescope, considered to be one of the most expensive piece of space equipment built by NASA, could provide deeper images of space than Hubble.