NASA’s Nancy Grace Roman Space Telescope Launches to Find Exoplanets and Unravel Mysteries of Dark Matter and Dark Energy
The new observatory will complete three surveys of the universe in five years, although it’s designed to function at least twice as long. Its data could change scientists’ basic understanding of the cosmos
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Are we alone in the universe? How will the cosmos change over time—and meet its eventual end? NASA has just launched a massive observatory to help answer these questions and more in the coming years.
On August 30 at 7:26 a.m. Eastern time, the Nancy Grace Roman Space Telescope lifted off atop a SpaceX Falcon Heavy rocket from Florida’s Kennedy Space Center. It will spend the next five years mapping the universe and studying its expansion by keeping tabs on nearby galaxies and our own Milky Way, as well as hunting for exoplanets, stars, black holes and other celestial objects.
“In some ways, I could never believe that this moment would actually happen, and it is here and far more beautiful than I could have anticipated,” said Dominic Benford, Roman Space Telescope program scientist at NASA headquarters, right after the launch during a livestream. “We built this in order to provide emotionally impactful and scientifically impactful imagery for all of humanity, and I feel like we have managed to achieve that today.”
The observatory left Earth’s surface amid a backdrop of golden light, the morning sun low in the sky.
The new telescope was named after NASA’s first chief of astronomy and female executive, Nancy Grace Roman, who died in 2018. She is often considered the “mother of the Hubble Space Telescope” because of her work advocating for space-based astronomical instruments in the 1960s and beyond.
Now, after 16 years of planning and development, the Roman Space Telescope is an 18,000-pound observatory that’s around 42 feet long by 14 feet wide, or roughly the size of a tour bus. Its primary goal is to complete three surveys that will help address questions about exoplanets and the evolution and structure of the universe, designed with input from the global scientific community.
“Almost regardless of what your scientific interest is, Roman is probably already planning to take observations,” said Julie McEnery, a Roman Space Telescope senior project scientist at NASA Goddard Space Flight Center, during a July 29 press briefing.
For the main survey, Roman will map about one-eighth of the entire sky and capture data on more than one billion galaxies, enabling researchers to look at how these and other structures have grown and evolved. It’ll also measure how the universe has expanded over time, which will help reveal secrets of dark matter, invisible stuff that acts like cosmic glue, and dark energy, the force suspected of driving the universe’s accelerating expansion.
These observations are especially exciting now, because in the past decade, astrophysicists have started to suspect flaws in the standard model of cosmology, a theoretical framework that describes the universe and its evolution, McEnery said.
“There are hints that the distribution of matter, the structure of matter in the universe, is not quite right, and there are even hints that the cosmological constant, a constant property of space-time, is in fact not constant,” she added. With Roman data, “we’re very likely to demonstrate that our standard model is wrong, and to set ourselves on a path to figuring out how does our universe really work.”
Roman will keep an eye on objects for this survey over about 17 months, intermittently, using its Wide Field Instrument. It’s a 300-megapixel camera that sees in infrared light with the same sensitivity and sharpness as Hubble—but with a field of view at least 100 times larger. It can also observe the sky about 1,000 times faster than the 36-year-old telescope can.
For comparison, McEnery said, “one month of observations to survey our Milky Way galaxy would take about a century with Hubble.”
Another survey, which will take about six months, will examine stellar explosions—supernovas—and other brightness-changing events in our Milky Way. These targets will help measure how the universe expanded in the past. And the third survey, slated to take roughly 15 months, will examine the clump of stars at our galaxy’s core to search for possible exoplanets.
Roman will also test a coronagraph, an instrument that can block starlight and reveal the dim light reflected off orbiting companions, particularly small, cool ones and those close to their host stars. The device is designed to be 100 to 1,000 times more powerful than any previous space-based coronagraph, and it will look at previously detected exoplanets to uncover new details about them. Its success would be key to NASA’s upcoming Habitable Worlds Observatory, which will look for signs of life on distant celestial bodies.
Although Roman is scheduled to complete all three surveys within a five-year primary mission period, it was built to function for another five years. The observatory’s development, launch and operations have a total budget of about $4.3 billion, and so far, costs have stayed a few million dollars under expectations, Benford said during an August 6 public talk at NASA headquarters. Roman’s timeline is also running several months ahead of schedule, he added.
Did you know? Designed to be complementary
Roman was made to capture data complementary to that of the Vera C. Rubin Observatory, which began its ten-year survey of the night sky from Chile in June. Rubin sees in visible light, which is bluer than what Roman sees, and Roman will have a better resolution than the ground-based telescope. NASA’s McEnery described them as “siblings embarking on a life of exploration.”
Before the observatory can map the universe’s mysteries, however, it’ll need to approach its final destination roughly one million miles away from Earth’s surface, which will take a little more than three months. During that travel time, researchers will be calibrating and testing Roman’s instruments. At its target site, called the second Lagrange point, it will join the James Webb Space Telescope in observing the universe.
The first images should arrive in December. “It could be around Christmas, so hopefully that’s a nice present,” Benford told NBC News’ Denise Chow in June.
Still, Roman will not have reached its resting spot when it sends those first observations. “It’ll still be on its cruise out there … a few weeks away from getting to that point,” Benford said during the public talk. However, the observatory will be far enough from the influences of the sun, moon and Earth to stabilize and start snapping images.
Once Roman begins collecting survey data, that information will quickly get beamed to Earth—in massive amounts.
“We’re talking about sending about one terabyte of data down to the ground every day. This is kind of like streaming a million songs from a million miles from Earth down to Earth,” said Jeremy Perkins, Roman Space Telescope integration and test scientist at NASA Goddard, at the press briefing.
Those observations will be made public immediately, allowing researchers, teachers and science enthusiasts alike to have access.
“I’m truly excited about the way that it’s going to change our understanding of the universe,” said Jackie Townsend, Roman Space Telescope project manager at NASA Goddard, during the press briefing.
“And in doing so, the next Dr. Nancy Grace Roman, sitting in a classroom somewhere next year, will be studying our data and hopefully catch the science bug and go on to transform the world.”
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