Duke Cosmologists Help Launch a New Era of Discovery

The rocket rose past the rising sun on a muggy Florida morning.  

A few miles away, on bleachers outside Kennedy Space Center’s Apollo/Saturn V Center, Duke professors, students, alumni and staff craned their necks as the rocket climbed impossibly high, leaving only contrails as it left the atmosphere. The PA updated the crowd: The Falcon Heavy boosters had split from the main rocket, and still it climbed. As designed, one booster tumbled, fast, firing at the seeming last second to land a short distance from its original launch site. Sharp sonic booms, triple-cracks like an improbably loud snare drum, followed the landing. 

The booster and its twin, which landed on a drone ship in the Atlantic, had done their job. The Nancy Grace Roman Space Telescope was off-world and headed to its destination, a million miles away. Dan Scolnic, in the bleachers, and Michael Troxel, on a nearby balcony, saw the future of cosmology research vanish beyond the blue sky overhead.

For the two professors of Physics, the Nancy Grace Roman launch represented years of work finally coming to fruition.

Scolnic and Troxel co-lead the Duke SPACE Initiative, the umbrella over all things space at Duke University. While physicists plumb the nature of the universe by studying interstellar phenomena like dark matter and supernovae, the SPACE Initiative also includes scholars in law, medicine, history, economics, public policy and business, reflecting the big bang that has pushed the study of space far beyond the sciences and the exclusive purview of government agencies like NASA, into private commerce and everyday technology, some of which relies on satellites. Space is big business, but space is still big science. In that, two Duke cosmologists are key players. 

“The Nancy Grace Roman Space Telescope is NASA's next flagship mission,” says Scolnic. 

As co-principal investigator of the Roman Supernova Project Infrastructure Team, Scolnic’s team writes software so that, once Roman is in position, researchers worldwide can make sense of its data. By doing this, he builds key infrastructure for the space telescope. Scolnic’s research looks at a certain type of supernova, which explodes in a similar way every time, to calculate the universe’s expansion rate — a highly debated scientific problem.  

“When you find one, you could figure out how far away it is,” Scolnic says. “That allows us to map how big the universe is at different stages of the universe. From that, we understand how the universe grew up.” 

Roman will find thousands of supernovae, allowing for precise measurements. It can see much more sky, so to speak, than Hubble could, says Troxel. It’s faster. Its camera is 100 times larger. 

“[Roman] can do what Hubble could do in a thousand years in just one year,” Troxel says. 

Troxel chairs the Roman Simulations Technical Working Group, preparing simulations of what the telescope will see and the data sets it will generate, so that researchers will be prepared for the real thing. He is also on the steering committee for the High-Latitude Imaging Survey (HLIS) Project Infrastructure Team, which develops scientific infrastructure ahead of the wide survey Roman will do.  

Duke is also providing HLIS with High-Performance Computing (HPC) resources. These will be used to further process the Roman Wide-Area Survey and produce publicly available data product and calibration information. Troxel is Principal Investigator of this Duke-led HPC effort, through which 18 collaborating institutions will be able to access these HPC resources at the North Carolina Shared Research & Education collaborative infrastructure (NCShare).

“Ninety-five percent of the universe appears to be something that doesn’t fit into our physics model,” Troxel says. “Who knows what we could do if we understood that 95 percent?” 

He refers to the mysterious and invisible dark matter, which he summarizes as “extra mass,” and dark energy, which causes things to accelerate away from each other. The two combine in complicated ways. They’re detected by faint distortions, where light is bent by gravity, indicating a source of mass. Some sources of mass, like stars, we can see. Some, like dark matter, we can’t.

Other things are simply too faint to see without a space telescope. 

“Some of the most dramatic things that we learned about the universe came from looking where we couldn't see anything,” Troxel says. 

Simply pointing Hubble at a seemingly blank patch of universe resulted in finding millions of galaxies never before discovered, Troxel says. And now Roman — Hubble’s Information Age grandchild — sails through space, ready to aim its powerful lenses into the cosmos seeking supernovae, dark matter, dark energy and perhaps even exoplanets capable of supporting life. 

With Roman safely launched into the sky, Troxel, Scolnic and the entire cosmology group at Duke have a couple more months to get ready: The telescope’s first images and batch of data are expected later this year. 

“It’s total game on once the images start coming in,” says Scolnic.