With NASA’s operations under existential threat from the Trump administration, maybe it’s not surprising that the agency will be taking a much needed moment to zone out and gaze into a void or two — albeit in a billion-light-year stare that’ll plumb the mysteries of the abyss.
On Monday, the agency described how a survey will use its upcoming Nancy Grace Roman Space Telescope to inspect puzzling regions of the universe called cosmic voids where few, if any, galaxies are found.
Though they appear empty, the voids could contain insights into the universe’s evolution — and illuminate the mysterious forces that govern it, dark matter and dark energy.
“Roman’s ability to observe wide areas of the sky to great depths, spotting an abundance of faint and distant galaxies, will revolutionize the study of cosmic voids,” said Giovanni Verza of the Flatiron Institute and New York University, lead author of a new study published in The Astrophysical Journal demonstrating how Roman could examine voids, in a NASA statement.
Cosmic voids potentially challenge a key notion in astrophysics known as the Copernican or cosmological principle. An extension of Copernicus’ insight that the Earth does not occupy a special place in the universe, the principle holds that on the largest scales, the universe should appear largely homogenous with matter evenly and randomly distributed.
But astronomers have been spotting cosmic voids tens of millions — and sometimes even hundreds of millions — of light years across, which poke formidable holes in the idea that the cosmos should look basically the same in every direction, from any position. The voids form the center of “bubbles” on the surface of which galaxies cluster together, sort of like dust clinging to a balloon — a sign that galaxies aren’t randomly distributed but themselves constitute even larger structures. Some of these structures span billions of light years across.
Astronomers believe the voids provide a portal for examining dark energy, a mysterious and invisible force that’s hypothesized to account for nearly 70 percent of all “stuff” in the universe. The ordinary matter that everything from our planet to stars are made of, meanwhile, barely cracks five percent. If dark energy exists, it would explain why the cosmos is expanding at an accelerating rate, essentially pushing against the boundaries of reality and overpowering the gravity of all the matter inside it that tries to bring it crashing down.
“Since they’re relatively empty of matter, voids are regions of space that are dominated by dark energy. By studying voids, we should be able to put powerful constraints on the nature of dark energy,” said co-author Alice Pisani of the French National Centre for Scientific Research, in the NASA statement.
One of the surveys Roman will be conducting after its slated launch next October is the Roman High-Latitude Wide-Area Survey, in which it will examine the night sky away from the plane of our galaxy. In the study, the astronomers predict that the infrared telescope should detect and measure tens of thousands of cosmic voids as small as 20 million light-years across. Their focus is to investigate the shape of the voids, which would be influenced by dark energy and other cosmic forces. If on average the voids don’t appear spherical, then there’s something wrong with our assumptions of dark energy.
There’s considerable debate over whether voids defy or disprove the cosmological principle. Perhaps on a large enough scale, they form a piece of the universe’s homogenous puzzle like everything else. Or perhaps they’re a consequence of our flawed observations. Whatever the answer may be, Roman will help us get closer to finding one.
“Voids are defined by the fact that they contain so few galaxies. So to detect voids, you have to be able to observe galaxies that are quite sparse and faint, explained co-author Giulia Degni of Roma Tre University in the statement. “With Roman, we can better look at the galaxies that populate voids, which ultimately will give us greater understanding of the cosmological parameters like dark energy that are sculpting voids.”
More on space: Scientists Detect Huge Rotating Structure in Space
The post NASA Says It’s Just Gonna Stare Into Cosmic Voids for a While appeared first on Futurism.
