NASA's new Nancy Grace Roman Space Telescope is about to launch. Here's why it's so cool.
Expect "the weird, the rare and the unusual," a NASA scientist predicted on Wednesday. "We'll redefine what it means to find a needle in a haystack."
It's been more than 36 years since NASA sent its Hubble Space Telescope into low-Earth orbit, and nearly five years since the agency's James Webb Space Telescope started to circle the sun. Now a new, even more advanced hunk of astronomical hardware is set to follow its two pioneering predecessors into the cosmos: the Nancy Grace Roman Space Telescope.
After more than a decade in development, the Roman Space Telescope will launch at 7:20 a.m. on Aug. 30 from NASA's Kennedy Space Center in Florida — nine months ahead of schedule. Its mission? To study how the universe began, what it's made of and how it has evolved over time — while (hopefully) helping scientists solve some of modern astronomy's biggest mysteries in the process.
NASA experts previewed that mission at a virtual news conference on Wednesday.
"Roman's vast reach will allow us to find the weird, the rare and the unusual," said Julie McEnery, the telescope's senior project scientist. "We'll redefine what it means to find a needle in a haystack."
What kinds of needles will Roman find in the vast haystack of space? Habitable planets in our own galaxy, perhaps. Dark energy. The inner workings of primordial black holes.
"We'll be exploring patches of sky as a function of time with exquisite sensitivity," McEnery continued. "We'll find new things that go bump in the night. I very much hope, and in fact expect, that the most exciting things from Roman will be a surprise — something that we couldn't predict."
To understand why the Roman Space Telescope matters, you first have to understand how it's different. Hubble mainly picks up visible light; Webb sees deep into the infrared part of the spectrum. Since light takes an unfathomably long time to travel from one end of the universe to the other, both space telescopes can peer far into the "past" — nearly back to the Big Bang, more than 13 billion years ago. But Webb — which also orbits in a quieter, darker part of space than Hubble, with less visual noise to block out — can capture distant celestial bodies in much greater detail.
In some ways, the new, 42-foot-long Roman Space Telescope resembles Webb. It too can see infrared light, and it will join its slightly older cousin at the second Lagrange point — a sweet spot in our tug-of-war with the sun, nearly 1 million miles from Earth. But Roman's mirror — the part of the camera that collects light, like a bucket in a rain shower — is Hubble-sized (7.9 feet) rather than Webb-sized (21 feet). So Roman's images of the universe will be less detailed as a result.
What those images lack in relative resolution, however, they will more than make up for in sheer scope. With 18 sensors, Roman's 300-megapixel camera is what's known as a wide-field instrument — a panoramic technology rarely deployed in space until now. Roman's field of vision is 100 times larger than Hubble's, meaning it can survey the sky 1,000 times faster. Over the next five years, NASA expects Roman to cover 50 times as much interstellar territory as Hubble covered over three decades. By the end of its life, Roman will have measured the light from two billion galaxies.
"We would need over half a million 4K TVs to fully display a single Roman image," McEnery explained on Wednesday. "To understand the scale, these TVs would cover 45 Manhattan city blocks, or fully cover El Capitan in Yosemite National Park. "
Why is such a wide field of vision important? Because the more sky you can survey, quickly and efficiently, the more "one in a million" leads you can generate — leads that Webb (and even Hubble) can then follow up on.
According to NASA, the Roman Space Telescope will yield deep 3D images enormous enough to help astronomers probe whether an enigmatic, theoretical pressure called "dark energy" is actually making the universe expand faster over time. It will observe how clumps of dark matter warp the appearance of distant galaxies, potentially altering our understanding of the architecture of the universe itself. And it will sharpen our search for exoplanets by using a tool called a coronagraph to capture the first direct images of mature worlds similar to some of the planets in our outer solar system.
"We have a straightforward, in a cosmological sense, way to explain how the universe works," McEnery said on Wednesday. "But there have been hints in the last five to 10 years that all is not well with our standard model" — which means Roman will likely "demonstrate that our standard model is wrong and to set us on a path to figuring out how our universe really works."
"And it's hard to get better than the fundamental nature of your universe," McEnery concluded.
Fittingly, the Roman Space Telescope is named for Nancy Grace Roman — a trailblazing astronomer who classified different types of stars, measured how they moved and served as NASA's chief of astronomy in the 1960s and '70s. Known as the "Mother of Hubble," Roman was the agency's first woman executive. She died in 2018 at the age of 93.
In 2011, Roman recalled asking her high school guidance counselor if she could take second-year algebra instead of Latin. "She looked down her nose at me and sneered, 'What kind of lady would take mathematics instead of Latin?'" Roman told Voice of America. "That was the sort of reception I got most of the way."
On Wednesday, project manager Jackie Townsend evoked Nancy Grace Roman when asked what excited her most about NASA's latest space telescope.
"I watched Hubble's findings change our understanding of the universe and change the textbooks that I was using to study in college," Townsend said. "[Now] the next Dr. Nancy Grace Roman, sitting in a classroom somewhere next year, will be studying [Roman's] data, and hopefully catch the science bug — and go on to transform the world in the same way that Dr. Nancy Grace Roman did."