As the Nancy Grace Roman Space Telescope (Roman) launches on its cosmic journey, it will soon send back stellar images, giving us a sharp, detailed view of the universe beyond our planet. But one of the main drivers of its mission will be the study of what we cannot see.
While we cannot see dark matter or dark energy, scientists suggest that both may help shape the structure of the universe. Previous missions have gathered data on these components, but NASA built Roman specifically to explore these mysterious forces in more depth.
What Is Dark Energy and Dark Matter?
According to NASA, dark matter is like the glue that holds the universe together. Though it’s invisible, the material surrounds us and makes up a bulk of the mass in the universe.
“Fundamentally, the physics of our universe is driven by the components that make up everything that we know of,” Dominic Benford, the program scientist for the Nancy Grace Roman Space Telescope, told Discover. “All the matter that makes up people and cats and dogs and the Earth and the sun and all the galaxies that we see comprise about maybe 5 percent of the total mass-energy budget of the entire cosmos.”
Explore All OptionsWe can’t see dark matter, but NASA estimates that it makes up about 27 percent of the total mass-energy budget in the universe (while dark energy makes up about 68 percent, but more on that later).
According to Benford, dark matter is similar to regular matter, except that while it interacts with gravity, it doesn’t interact with light. However, because dark matter has mass, astronomers can ‘see’ dark matter interacting with regular matter around it.
Dark energy, in theory, is the force that is expanding the universe outward.
“The importance of dark energy is that it is the driving force that really dominates most of the reality of our universe,” Benford said.
Besides knowing that dark energy is a force of energy, driving universe expansion, and that it may make up about 68 percent of the universe’s contents, not much else is known about it. But Roman could change that.
Read More: How Nancy Grace Roman, the ‘Mother of Hubble,’ Became the Namesake of NASA’s New Telescope
Studying Dark Matter
Roman is also equipped with a powerful wide-field infrared survey instrument, meaning it can capture and process images of large sections of the sky and send them back to Earth for study. Thanks to the large view, astronomers could study a phenomenon known as gravitational lensing, which occurs when a massive object, like a black hole or galaxy cluster, bends the path of light from a source that may be behind it, according to NASA.
“It’s like looking through a cosmic funhouse mirror. It can smear or duplicate distant galaxies, or if the alignment is just right, it can magnify them like a natural telescope,” Ryan Hickox, a professor of physics and astronomy at Dartmouth and co-chair of a NASA committee that shaped the survey’s design, said in a press release.
Because Roman’s field of view will be so large, researchers could study this phenomenon on a smaller scale and see how dark matter's gravitational influence may change the appearance of distant cosmic objects. From this data, astronomers will then build out detailed maps of how matter is distributed, according to NASA. From there, they will then study how these structures grow over time, which will assist in studying dark energy.
Read More: Roman Could Find Thousands of New Worlds — Here’s How the Telescope Hunts for Exoplanets
Studying Dark Energy
According to NASA, Roman’s wide-area survey will also help to gather light and spectra from about 20 million galaxies. Analyzing these objects will help researchers better understand how fast the universe is expanding during different cosmic eras. As objects move away, the light waves from them stretch and shift toward redder wavelengths, according to NASA. This phenomenon is known as redshift.
Using this data, researchers could tell how far away something is in space. The more redshift, the farther away an object is. From here, astronomers will compile a 3D map of the galaxies that fall into the field of view from a distance of about 11.5 billion light-years away.
“Roman’s imaging survey combined with its redshift survey gives us new information about the evolution of the universe — both how it expands and how structures grow with time — that will help us understand what dark energy and gravity are doing at unprecedented precision,” Risa Wechsler, director of Stanford University’s KIPAC (Kavli Institute for Particle Astrophysics and Cosmology) in California and co-chair of the committee that shaped the survey’s design, said in the press release.
Read More: Why the Roman Telescope Is Bound For a Cosmic Sweet Spot Far Beyond the Moon
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from NASA: Core Survey by NASA’s Roman Mission Will Unveil Universe’s Dark Side
- This article references information from NASA: Dark Matter
- This article references information from NASA: Dark Energy
