Universe Contains 2 Trillion Galaxies, A New Study Reveals
A new study reveals that the universe contains an amazing 2 trillion galaxies, 10 times more than previously thought. In the past 20 years, scientists estimated around 100 to 200 billion galaxies in the universe based on the images collected by the Hubble Space Telescope.
The findings of the study were printed in the Astrophysical Journal on Jan. 16, 2017. It was led by Christopher Conselice, Professor of Astrophysics at the University of Nottingham, and other colleagues.
Professor Conselice said that it is very surprising to know that over the 13.7 billion years of cosmic evolution since the Big Bang, galaxies have been growing through star formation and merging with other galaxies. He further said that finding more galaxies in the past implies that significant evolution must have occurred to reduce their number through an extensive merging of systems.
He added that they are missing the clear majority of galaxies because they are very faint and far away. Professor Conselice also said that the number of galaxies in the universe is a fundamental question in astronomy. He asked then, "Who knows what interesting properties we will find when we study these galaxies with the next generation of telescopes?"
The team based its calculations on the pencil beam images of deep space from telescopes around the globe and from Hubble Space Telescope into 3-D maps. The researchers were able to gauge the density of galaxies and the volume of one small region of space after another.
Then, they determined how many galaxies they have missed. They also based their findings on the measurements of the number of observed galaxies at various epochs -- different instances in time -- through the universe's history. The team assessed how many galaxies there were at a given epoch and discovered that they were significantly more at earlier times. So, when the universe was only a few billion years old, there were 10 times as many galaxies in each volume of space as there are within a similar volume today, according to Phys.org.
The universe comprises of moons, planets, stars, galaxies, minor planets, all matter and energy and the contents of intergalactic space. Its size is unknown. One of the galaxies in the universe is the Milky Way galaxy, in which the Solar System resides. In the 20th century, studies indicated that the universe had a beginning and it is expanding at an increasing rate. Its mass seems to be visible in the unknown form known as "dark matter."