The United States National Aeronautics Space Administration (NASA) on Sunday, August 30, launched its Roman Space Telescope, combining a panoramic view of the cosmos with powerful tools for probing dark energy and hidden worlds.
The Nancy Grace Roman Space Telescope, built to see the universe in a way no major space telescope has before, will combine Hubble-like sharpness with a field of view 100 times larger, allowing it to sweep across enormous regions of the sky far faster than Hubble ever could. It will hunt for distant galaxies, dark matter, dark energy, dying stars, and planets hidden in the glare of other suns.
Several University of Arizona faculty members and students were at Cape Canaveral for the launch of the agency’s next flagship astrophysics mission, whose science operations are expected to begin in January 2027, after the James Webb Space Telescope, designed to look deeply into relatively small regions of space.
Both telescopes can observe infrared light, enabling astronomers to be able to compare and combine their observations. Together, Roman and Webb could provide a more complete picture of the universe than either mission could produce alone.
Roman’s primary mirror measures 7.9 feet across, the same size as the Hubble Space Telescope’s mirror. But one of Roman’s instruments will give it a dramatically wider view.
The Wide Field Instrument is designed to match the sensitivity of Hubble’s cameras while imaging an area 100 times larger.
Hubble has observed roughly 0.1 percent of the night sky during more than 30 years in space while Roman has the potential to cover the entire sky at the same resolution.
That sweeping view should make Roman especially good at finding rare objects. Scientists expect it to capture everything from dying stars and new worlds to massive galaxy clusters.
University of Arizona researchers will help turn those observations into new discoveries.
While Webb was designed to look deeply into relatively small regions of space, Roman’s strength will be breadth.
Among Roman’s biggest targets are two of the deepest mysteries in cosmology: dark matter and dark energy.
Dark matter does not give off light, but its gravity affects galaxies and other structures throughout the universe, while dark energy is the name scientists give to the mysterious influence associated with the accelerating expansion of the cosmos.
Together, these invisible components make up nearly all of the universe.
NASA selected the U of A’s Arizona Cosmology Lab to support two investigations aimed at understanding their nature, one involving a wide-field science team and another involving project infrastructure.
Professor of Astronomy and Physics, Elisabeth Krause leads the wide-field science team, ‘Kinematic Lensing with the Roman Space Telescope.’
The team received $2 million to develop a cosmological measurement method called kinematic lensing.
By combining Roman images with spectroscopic data, the researchers hope to measure dark matter and dark energy more precisely than before.
Another U of A group will take a leading role in the multi-institutional project infrastructure team known as ‘Maximising Cosmological Science with the Roman High Latitude Imaging Survey.’
Another professor of Astronomy and Physics, Tim Eifler leads the working group that will interpret Roman’s cosmological data.
Roman will detect galaxies both nearby and extremely far away. Astronomers will determine where those galaxies are located and measure their properties to build enormous catalogs.
Researchers will then use computer models to translate those catalogs into information about the underlying physics of the universe.
That requires substantial computing power.
The NASA Roman Project awarded Eifler’s lab $800,000 to purchase computing resources that will become part of a new university-wide high-performance computing system expected to arrive this fall.
The lab will receive another $2.4 million over five years to carry out the research.
“This infrastructure will take us from catalogs to cosmological interpretation. We’ll be able to do things like determine how much dark energy and dark matter are in the universe,” Eifler said.
Eifler, who also serves as co-chair of the cosmology group that brings together more than 1,000 scientists from around the world, added that “it’s fantastic to rally the community around this science case. This really is a dream job.”
Roman will not only map the large-scale universe. It will also test powerful new ways to directly image planets around other stars.
Its Coronagraph Instrument uses masks, prisms, detectors, filters, and self-flexing mirrors to suppress a star’s overwhelming light.
Once that glare is reduced, astronomers can try to see the much fainter planets and disks surrounding the star.
Nearly all known exoplanets have been discovered indirectly. One common method, for example, measures the tiny drop in starlight that occurs when a planet crosses in front of its star.
Roman’s coronagraph takes a different approach by attempting to reveal the planet itself.
The instrument is expected to detect planets that are 100 million times fainter than their host stars. That represents an improvement of 100 to 1,000 times over existing space-based coronagraphs.
“It will be a crucial pathfinder for a future Habitable Worlds Observatory,” a recommended telescope that would be specifically designed to search for signs of life in other solar systems, said Schuyler Wolff, an associate research professor of Astronomy leading the observation planning working group for the Coronagraph Instrument.
Several other University of Arizona researchers helped develop Roman’s Coronagraph Instrument and will participate in future observations.
They include Lunar and Planetary Laboratory director Mark Marley, associate professor of Astronomy, Ewan S. Douglas, Steward Observatory assistant research professor, Ramya Anche, and astronomy postdoctoral research associate, Justin Hom.
Marley, along with LPL associate professor, Ty Robinson and LPL postdoctoral research associate, Zarah Brown, plans to use coronagraph data to investigate the atmospheres of worlds beyond our solar system.
Brown has been modeling the climates and spectra of self-luminous giant planets. These planets are generally so young and hot that they produce their own thermal infrared light.
Her models predict atmospheric temperature, composition and clouds, as well as the infrared spectrum each planet should emit.
Those forecasts matter because many of these objects have never been studied at these wavelengths.
“That predicted spectrum is critical for planning.”
