There are around two trillion galaxies in the cosmos, at least 10 times more than ever thought.Astronomers using NASA’s Hubble Space Telescope say that the findings, to be published in the Astrophysical Journal, has focused on the evolution of the structure universe, and hint at the possible nature of dark matter.
“We now know that there are at least 10 times more galaxies in the universe than we had thought for the last 20 years, and before that we didn’t really have any idea,” said lead author Christopher Conselice, an astrophysicist at the University of Nottingham. “So the more we learn about the universe ... the more interesting it becomes.”
Based on the finding of 3D modelling of images collected over 20 years by the Hubble Space Telescope, was published in the Astronomical Journal. Scientists created a puzzle over how many galaxies the cosmos harbours at least since US astronomer Edwin Hubble showed in 1924 that Andromeda, a neighbouring galaxy, was not part of our own Milky Way.
Astronomers have a tried to look back in time, deeper and farther into space. They found that light from the sun takes about eight minutes to travel 93 million miles to Earth, so the image we see of the sun right now is actually the sun as it was eight minutes ago. The same guideline applies as you try to go to the depth into space.
About two decades ago, the Hubble Space Telescope took pictures of the distant, early cosmos, revealing what our 13.8-billion-year-old universe looked like in its childhood, more than 10 billion years ago. Astronomers calculated that the universe must hold around 100 billion galaxies. (Estimates range from about 100 billion to 200 billion, Conselice said.)
If galaxies started out small and plentiful, and then grew and consolidated over time, it would support an idea called the ”cold” dark matter hypothesis over the ”hot” dark matter one, Conselice said.Scientists are also looking forward to the launch of NASA’s James Webb Space Telescope in 2018, which will be able to look deeper into the infrared — and so even farther back in time and space.
The James Webb telescope will “more than double the number of galaxies that we can see today, so explore a whole new regime of galaxies that we cannot study yet,” Conselice said.