Next year, NASA’s Nancy Grace Roman Space Telescope is set to launch—and scientists believe it could change everything we know about dark matter, the mysterious substance that makes up most of the matter in the universe.
While dark matter can’t be seen directly because it doesn’t give off or reflect light, its gravity can bend light from other objects—a cosmic trick known as gravitational lensing.
This bending of light lets scientists use some galaxies like natural magnifying glasses.
When a galaxy’s mass, including its dark matter, warps the light from a galaxy behind it, astronomers get a better view of what lies far beyond.
Roman’s powerful camera will help researchers find and study thousands of these lensing events with much greater detail than ever before.
A recent study led by an international research team, including Yale University astrophysicist Priyamvada Natarajan, predicts that Roman could discover more than 160,000 gravitational lenses.
About 500 of those will be clear and sharp enough to study the fine structure of dark matter—something that could help scientists finally understand what it’s really made of and how it behaves.
Natarajan, a leading theorist in the study, says Roman will help scientists spot much smaller clumps of dark matter than previously possible.
These tiny clumps are believed to have played a big role in the early formation of galaxies.
Being able to see them more clearly could give us new insight into how the universe evolved. The telescope’s camera, called the Wide Field Instrument, can detect tiny distortions in light—about as precise as spotting the width of a human hair from over 200 meters away.
Currently, the most widely accepted theory of how the universe developed is called the Lambda Cold Dark Matter model.
Roman’s ability to study gravitational lensing in detail will allow scientists to test this theory on much smaller cosmic scales than ever before. That could either strengthen confidence in the model or reveal surprising new details about how the universe works.
In the meantime, researchers are preparing by analyzing data from other powerful observatories. These include the European Space Agency’s Euclid mission and the upcoming Vera C. Rubin Observatory in Chile, which will soon begin full-scale operations.
Once Roman is in orbit, its images will be combined with data from Euclid, Rubin, and even the Hubble Space Telescope to get the clearest view yet of the cosmos.
The new study was led by graduate student Bryce Wedig and supervised by Tansu Daylan at Washington University in St. Louis. As the countdown to Roman’s launch begins, astronomers around the world are eager to see what secrets the universe may finally reveal.
Source: Yale.
