In a groundbreaking effort to preview what awaits the scientific community upon the launch of NASA’s Nancy Grace Roman Space Telescope in 2027, astronomers have released a remarkable collection of over a million simulated images that illustrate how the cosmos will appear through Roman’s instruments. The images, generated through advanced computer simulations, aim to provide scientists a window into the vast universe the telescope will explore, helping to chart a course for the wealth of science to come. By leveraging some of the most powerful computing capabilities available, this project stands as the largest and most detailed synthetic cosmic survey ever made.
Building the Universe in a Supercomputer
This ambitious endeavor, known as OpenUniverse, has created a synthetic universe using the processing power of a supercomputer at the Department of Energy’s (DOE) Argonne National Laboratory in Illinois. Michael Troxel, an associate professor of physics at Duke University and the campaign’s lead scientist, highlighted the significance of the project: “We used a supercomputer to create a synthetic universe and simulated billions of years of evolution, tracing every photon’s path all the way from each cosmic object to Roman’s detectors. This is the largest, deepest, most realistic synthetic survey of a mock universe available today.”
The team turned to the now-retired Theta supercomputer, known for its extraordinary computational power. What would have taken over 6,000 years on a typical computer was achieved in just nine days with Theta’s immense capacity. This level of detail brings the simulated cosmos to life, enabling scientists to plan, test, and calibrate observations before Roman begins its own data collection.
OpenUniverse: A Comprehensive Snapshot of the Universe
The dataset from OpenUniverse, which spans a stunning 400 terabytes, provides a preview not only for NASA’s Roman mission but also for other major projects. Along with simulations based on Roman’s capabilities, the OpenUniverse data includes approximations for observations from the Vera C. Rubin Observatory and the European Space Agency’s Euclid mission, both of which share NASA’s contributions. The team has made the Roman-related dataset available to researchers now, with the data from Rubin and Euclid expected to follow shortly.
In terms of spatial and temporal scale, the OpenUniverse simulations provide scientists with data over a vast area and time period, giving them invaluable insight into the cosmos at an unprecedented scale. The simulations span 70 square degrees of the sky—an area roughly the size of more than 300 full moons—and cover over 12 billion years of cosmic evolution. This extraordinary space-time coverage helps scientists anticipate how the upcoming telescopes will provide critical insights into some of the biggest unanswered questions about the universe, such as the nature of dark energy and dark matter.
Unlocking the Secrets of Dark Matter and Dark Energy
The insights gained from studying this synthetic universe will allow astronomers to probe phenomena that have puzzled physicists for decades. For instance, Roman’s capabilities will support investigations into dark energy, the mysterious force believed to be responsible for the accelerated expansion of the universe. Similarly, dark matter—an invisible substance detectable only through its gravitational effects on visible matter—will also be a prime focus. Roman’s highly detailed imaging will allow scientists to observe the effects of dark matter on galaxies and galaxy clusters over vast expanses of time.
By analyzing the data from OpenUniverse, scientists will simulate how galaxies and galaxy clusters evolve, providing a rich understanding of cosmic structures and the fundamental forces that shape them. The simulated images depict interactions between various elements of the universe, allowing researchers to study events like exploding stars, known as supernovae, which release immense energy. These simulated phenomena will assist scientists in mapping the expansion of the simulated universe, a key goal for missions like Roman that aim to explore cosmic growth over billions of years.
Preparing for the Data Deluge: How to Handle Roman’s Data
When Roman takes to the skies in 2027, the sheer volume of data it will generate will overwhelm traditional methods of analysis. Scientists expect Roman to return data at an unprecedented rate, making it impractical for researchers to manually sift through every piece of information. With this in mind, astronomers have already begun developing advanced systems to automate the processing of Roman’s observations.
One vital component of this process is the creation of an alert system designed to notify astronomers of significant cosmic events, such as supernovae or the formation of galaxy clusters. This will allow scientists to quickly prioritize their observations of high-interest phenomena. As Alina Kiessling, a research scientist at NASA’s Jet Propulsion Laboratory and principal investigator of OpenUniverse, explains, the main challenge will be to differentiate between different types of cosmic events and determine their relevance to ongoing studies. “Most of the difficulty is in figuring out whether what you saw was a special type of supernova that we can use to map how the universe is expanding, or something that is almost identical but useless for that goal,” she says.
In addition to the alert system, teams are also developing machine-learning algorithms capable of analyzing the incoming data. These tools will help filter out unnecessary information and highlight relevant events, easing the burden on astronomers and accelerating the scientific process. This step is critical, as Roman will be capable of completing surveys that would take other observatories, such as the Hubble Space Telescope or the James Webb Space Telescope, thousands of years to accomplish—significantly reducing the time required to explore vast stretches of the universe.
The Roman Telescope: A Leap in Scientific Discovery
The significance of Roman’s mission cannot be overstated. With its ability to complete surveys that would take other space telescopes thousands of years, Roman promises to make discoveries that could fundamentally transform our understanding of the cosmos. Scientists expect it to create 3D maps of galaxies and galaxy clusters, delve into the mysteries of star formation, and provide groundbreaking insights into the expansion of the universe.
One of the project’s key goals is to uncover how the universe expanded over time, which will help answer fundamental questions about its past and future. The simulation results already give a taste of what’s to come, but when Roman sends back real data, the possibilities for groundbreaking discoveries are staggering. According to Kiessling, the mission’s potential for revolutionizing our understanding of the universe is immense: “We can expect an incredible array of exciting, potentially Nobel Prize-winning science to stem from Roman’s observations.”
The Post-Roman Era: Continued Use of Simulations
Even after the Roman Space Telescope is launched, the OpenUniverse project will continue to serve as a critical tool for refining our understanding of the universe. One of the most exciting aspects of the mission is the ability to compare real observations to simulations, essentially engaging in a cosmic “game of spot the differences.” This process will allow scientists to assess how accurately their models reflect the true nature of the cosmos.
According to Katrin Heitmann, a cosmologist and deputy director of Argonne’s High Energy Physics division who managed the project’s supercomputer resources, discrepancies between real and simulated observations can open doors to new physics. “If we see something that doesn’t quite agree with the standard model of cosmology, it will be extremely important to confirm that we’re really seeing new physics and not just misunderstanding something in the data,” Heitmann says. The ongoing process of comparing simulated and actual data will provide important insights, helping scientists to refine the models and interpretations driving our understanding of cosmic phenomena.
Looking Ahead: A New Era in Astronomy
In just a few short years, when the Nancy Grace Roman Space Telescope takes flight, it will unlock new realms of cosmic discovery. With its innovative ability to deeply observe both the present and past state of the universe, Roman will shed light on phenomena ranging from dark matter and dark energy to the formation and evolution of galaxies. Alongside Euclid and Rubin, the telescope will form an unparalleled triad of observatories exploring the deepest corners of space and time. As astronomers prepare for the enormous amount of data Roman will generate, the OpenUniverse simulations lay the groundwork for the next great era of exploration in astronomy.