Two previously invisible Galaxies labeled REBELS-12-2 and REBELS-29-2 have been discovered by astronomers 29 Billion light-years from the Earth. These two galaxies (aptly named for any Star Wars enthusiasts) were previously undetectable to the optical mirrors of the Hubble Space Telescope and instead were finally spotted using the giant Atacama Large Millimeter Array (ALMA) in Chile’s Atacama Desert. The two galaxies were obscured by an astronomically massive layer of cosmic dust. But through the ALMA’s 66 antennae astronomers were able to generate a high-resolution image of them for the very first time.
“We were looking at a sample of very distant galaxies, which we already knew existed from the Hubble Space Telescope. And then we noticed that two of them had a neighbor that we didn’t expect to be there at all. As both of these neighboring galaxies are surrounded by dust, some of their light is blocked, making them invisible to Hubble,” explains Associate Professor Pascal Oesch of the Cosmic Dawn Center at the Niels Bohr Institute in a statement published in Science.
“Our discovery demonstrates that up to one in five of the earliest galaxies may have been missing from our map of the heavens. Before we can start to understand when and how galaxies formed in the Universe, we first need a proper accounting,” Oesch said.
The Skies Have More Invisible Wonders To Reveal
Curiously 10-20 percent of the universe’s galaxies have been so far undetected but using the ALMA and with the James Webb Space Telescope, which is expected to be launched into orbit on the 18th of December 2021.
“The next step is to identify the galaxies we overlooked, because there are far more than we thought. That’s where the James Webb Telescope will be a huge step forward. It will be much more sensitive than Hubble and able to investigate longer wavelengths, which ought to allow us to see these hidden galaxies with ease,” Pascal Oesch continued, adding:
“We are trying to put the big puzzle about the universe’s formation together and answer the most basic question: ‘Where does it all come from?’ The invisible galaxies that we’ve discovered in the early universe are some of the first building blocks of the mature galaxies we see around us in the Universe today. So that’s where it all began.”
In spite of multiple delays and cost overruns and at least one launch mishap the James Webb Telescope will soon supplement resources Earth-side like the Atacama Large Millimeter Array and continue the work of the aging Hubble Telescope in peeling back the layers of dust, darkness, and millennia between humanity and galaxies invisible to us for centuries.