How Large Is The Universe? A Lot Larger Than We Thought: An update

When I first posted this in 2013, three years ago, the Cosmos Has become even larger.

10 Times More Galaxies Than Scientists Thought!

More than a trillion galaxies are lurking in the depths of space, a new census of galaxies in the observable universe has found — 10 times more galaxies than were previously thought to exist.

An international team of astronomers used deep-space images and other data from the Hubble Space Telescope to create a 3D map of the known universe, which contains about 100 to 200 billion galaxies. In particular, they relied on Hubble’s Deep Field images, which revealed the most distant galaxies ever seen with a telescope.

Then, the researchers incorporated new mathematical models to calculate where other galaxies that have not yet been imaged by a telescope might exist. For the numbers to add up, the universe needs at least 10 times more galaxies than those already known to exist. But these unknown galaxies are likely either too
faint or too far away to be seen with today’s telescopes.

The image was taken by the Hubble Space Telescope and covers a portion of the southern field of the Great Observatories Origins Deep Survey (GOODS). This is a large galaxy census, a deep-sky study by several observatories to trace the formation and evolution of galaxies.

“It boggles the mind that over 90 percent of the galaxies in the universe have yet to be studied,” Christopher Conselice, a professor of astrophysics at the University of Nottingham in the U.K., who led the study, said in a statement. “Who knows what interesting properties we will find when we observe these galaxies with the next generation of telescopes.”

Looking far out into deep space also means looking back in time, because light takes a long time to travel across cosmic distances. During the study, Conselice and his team looked at parts of the universe up to 13 billion light-years away. Looking this far allowed the researchers to see partial snapshots of the evolution of the universe since 13 billion years ago, or less than 100 million years after the Big Bang.

They discovered that the early universe contained even more galaxies than it does today. Those distant galaxies were small and faint dwarf galaxies, they found. As the universe evolves, such galaxies merge together to form larger galaxies.

In a separate statement, Conselice said that the results are “very surprising as we know that, over the 13.7 billion years of cosmic evolution since the Big Bang, galaxies have been growing through star formation and mergers with other galaxies. Finding more galaxies in the past implies that significant evolution must have occurred to reduce their number through extensive merging of systems.”

Courtesy of Space.com

Universe has 2 trillion galaxies, astronomers say.

 

Hubble telescope images from deep space were collected over 20 years to solve the puzzle of how many galaxies the cosmos harbours.

The surprising find is based on 3D modelling of images collected the Hubble Space Telescope.

There are a dizzying 2 trillion galaxies in the universe, up to 20 times more than previously thought, astronomers reported on Thursday. The surprising finding, based on 3D modeling of images collected over 20 years by the Hubble Space Telescope, was published in the Astronomical Journal.

Scientists have puzzled over how many galaxies the cosmos harbors at least since US astronomer Edwin Hubble showed in 1924 that Andromeda, a neighboring galaxy, was not part of our own Milky Way. But even in the era of modern astronomy, getting an accurate tally has proven difficult.

To begin with, there is only part of the cosmos where light given off by distant objects has had time to reach Earth. The rest is effectively beyond our reach. And even within this “observable universe”, current technology only allows us to glimpse 10% of what is out there, according to the new findings.

“It boggles the mind that over 90% of the galaxies in the universe have yet to be studied,” commented Christopher Conselice of the University of Nottingham, who led the study. “Who knows what interesting properties we will find when we observe these galaxies with the next generation of telescopes?” he said in a statement.

Using deep space images from Hubble, Conselice and his team painstakingly converted them into 3D to measure the number of galaxies at different times in the history of the universe. The analysis reached back more than 13bn years – very near the time of the “Big Bang” thought to have given birth to the universe.

A galaxy is a system of millions or billions or stars, held together by gravity, with planetary systems within them. Using new mathematical models, the astronomers were able to infer the number of “invisible” galaxies beyond the reach of telescopes, leading to the surprising realisation that the vast
majority are too faint and far away to be seen.

When the universe was only a few billion years old, there were 10 times as many galaxies in a given volume of space as there are today, the findings suggest. This in turn suggests that “significant evolution must have occurred to reduce their number through extensive merging of systems”.

Courtesy of Theguardian.com

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