Researchers using NASA's Wide-Field Infrared Survey Explorer and a telescope in Maui have discovered what they are calling the "largest individual structure ever identified by humanity," reports the Royal Astronomical Society. So large, in fact, that the only way to measure its size is in light-years—1.8 billion of them. The so-called supervoid is about 3 billion light-years away, a distance astrophysicists call "close" in the scheme of things. The researchers were on the hunt for a supervoid in the direction of what's known as the cosmic microwave background (CMB) Cold Spot, they report in the Society's Monthly Notices. First discovered in 2004, the Cold Spot has led some to question our understanding of the Big Bang theory, which doesn't account for such large, cold spaces.
The latest study suggests that this supervoid—which isn't empty but rather less dense, essentially "missing" 10,000 galaxies, reports the Guardian—found in the middle of the Cold Spot drains energy from light that travels through it. Still, the mystery continues, as this drain accounts for only 10% of the Cold Spot's extreme temperature dip. "It's like the Everest of voids—there has to be one that's bigger than the rest," says one researcher. "But it doesn't explain the whole Cold Spot, which we're still in the dark about." Experts say "exotic physics" that we're not familiar with could be at play. Still, the discovery does provide evidence "for the existence of dark energy," an outside researcher says. (How close to absolute zero is the "coldest place in the universe"?)