If you don't want to be found, the universe is a good place to hide.
Needle, meet infinite haystack.
But as prying Earthling eyes scan the heavens, could entire galaxies remain on the lam?
According to research published in the journal Nature, they've been hiding from us for eons.
Ancient, secret galaxies, they say, have always been among us. We just had to look for them from a different perspective.
For scientists at the University of Tokyo, that perspective came from stepping away from our faithful eye in the sky — the Hubble Space Telescope — and using an innovative combination of modern observatories to squint at the stars.
And suddenly, there are 39 shiny new galaxies — all hiding in plain sight, and all offering fresh clues to solve the longstanding mysteries of dark matter and black holes.
"This is the first time that such a large population of massive galaxies was confirmed during the first two billion years of the 13.7-billion-year life of the universe," Tao Wang, from the university's Institute of Astronomy, explains in a press release.
"These were previously invisible to us."
Not only do these new galaxies represent vast new tracts of the universe for us to ponder, they may also offer key insight into how the universe evolved. For one thing, since they're not exactly the new kids on the block — but likely existed when the universe itself was still young — they've had billions of years to sprawl across space.
And where there are massive galaxies, there are supermassive black holes — and all the dark matter trimmings we can sink our scientific teeth into.
"The more massive a galaxy, the more massive the supermassive black hole at its heart. So the study of these galaxies and their evolution will tell us more about the evolution of supermassive black holes, too," study co-author Kotaro Kohno explains in the release. "Massive galaxies are also intimately connected with the distribution of invisible dark matter. This plays a role in shaping the structure and distribution of galaxies. Theoretical researchers will need to update their theories now."
To reveal these galaxies, researchers had to step away from Hubble, an optical telescope that can only respond to visual cues.
"The light from these galaxies is very faint with long wavelengths invisible to our eyes and undetectable by Hubble," Kohno notes.
Instead, researchers collected data from NASA's Spitzer Space Telescope, a space-based observatory that sees space in infrared. In all, Spitzer sniffed out 63 objects that we never knew were there. Researchers winnowed down their findings with the Chile-based Atacama Large Millimeter/submillimeter Array (mercifully shortened to ALMA).
And behold, 39 extremely active galaxies, all churning out a frantic number of stars — indeed, somewhere in the range of 1,000 of our suns annually.
"This paper demonstrates that we were missing 90 percent of the massive galaxies," Mauro Giavalisco, an astronomer at the University of Massachusetts, who was not involved in the research, tells the journal Science. "I think it will spur a lot of further research."
But the best is likely yet to come, as NASA prepares the James Webb Space Telescope, described as "the biggest, most powerful telescope ever to be put in space."
Set for a March 2021 launch, this landmark bundle of technology will leave even fewer stones unturned in the universe.
Fugitive galaxies, consider yourselves on notice.