We Have Found Hidden Ancient Galaxies, And It Can Change What We Know About The Universe

Though we've been peering at the cosmos for generations, there's still so much we don't know about it. That was demonstrated once more recently, when scientists used different instruments to find hidden galaxies the Hubble Space Telescope never spotted.

The discovery could help astronomers fill a hole in the puzzle of how the ancient universe evolved.

An artist's representation of the hidden galaxies - Images courtesy: NAOJ

The international team of researchers used a pair of instruments to peek into the depths of deep space and found dozens of ancient galaxies we've never seen before. Billions of light-years away, we've never seen these galaxies before because the little light reaching us is invisible to the human eye as well as optical telescopes like Hubble.

NASA's Spitzer Space Telescope first identified 63 previously unknown objects. The team couldn't really make out what they were though, so they instead turned to the Atacama Large Millimeter/submillimeter Array (ALMA). That was able to determine that 39 of the objects they'd spotted were massive galaxies each producing huge numbers of stars, about 1,000 of our suns every year.

And if we could see it, the researchers say it would be breathtaking.

"For one thing, the night sky would appear far more majestic. The greater density of stars means there would be many more stars close by appearing larger and brighter," lead researcher Tao Wang, an astronomer at the University of Tokyo, said in a statement. "But conversely, the large amount of dust means farther-away stars would be far less visible, so the background to these bright, close stars might be a vast, dark void."

Because they're so far away and how long it takes light to travel, scientists are looking at these galaxies as they existed during the first 2 billion years of the universe.

What's invisible to the Hubble Space Telescope is visible to the ALMA instrument

The thing is, they're not what we expected either. Scientists believe that galaxies become elliptical in shape as they age, like those close to the Milky Way. But the team found 10 times more of these young galaxies than expected.

For one, this means our current estimates of how much dark matter exists in the universe might be wrong. That's because those estimates would have made it impossible for so many large objects to have appeared early on in the universe's life.

Now the researchers are turning to the James Webb Space Telescope in the hopes of shedding more light on these galaxies that Hubble can't see. And there's no telling just how much we could learn about the formation of the universe from them.