We know that the universe is big – really big – and that there are a ton of galaxies out there that contain many kinds of different systems that may or may not support forms of life, but NASA now says that the observable universe may contain up to ten times more galaxies than previously thought.
Image Credit: NASA, ESA, the GOODS Team, and M. Giavalisco (University of Massachusetts, Amherst)
Suddenly, the universe feels a lot more crowded than it was before. The bold new theory, introduced by a survey from a team using NASA’s Hubble Space Telescope and other observatories around the world, suggests there’s a lot more going out there than we’ve given nature credit for.
The findings from a team of experienced astronomers have been accepted by The Astrophysical Journal.
"These results are powerful evidence that a significant galaxy evolution has taken place throughout the universe's history, which dramatically reduced the number of galaxies through mergers between them - thus reducing their total number. This gives us a verification of the so-called top-down formation of structure in the universe," explained Christopher Conselice of the University of Nottingham, U.K.
One thing the team found was that all of the galaxies found in the universe are not evenly distributed. Many of them are dim, like the ones surrounding ours, and many probably also merged together to make larger galaxies, which is why we think there appear to be fewer galaxies today.
Obviously, as we can’t see the event horizon of our universe, we also cannot see all of the galaxies just at its border. Nevertheless, at those distances, we also can’t see dim galaxies. The original number of 200 billion galaxies throughout the universe has reportedly been vastly underestimated, the team says.
"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? In the near future, the James Webb Space Telescope will be able to study these ultra-faint galaxies, said Conselice.
Although we might consider every single patch of the night sky to contain some kind of galaxy or starlight with these new numbers, there’s just too much going on in space for everything to be visible. The expansion of space and chemistry of our atmosphere are just some of the things that blind us.
Of course, space telescopes help a bit, since they’re not shielded by our atmosphere, but their field of view is still limited.
It looks like we're just going to need a bigger and better space telescope...
Source: NASA