NASA’s next flagship space observatory has a launch date. The Nancy Grace Roman Space Telescope is scheduled to launch from Kennedy Space Center in Florida on Sunday, Aug. 30, aboard a SpaceX Falcon Heavy rocket. The launch comes roughly nine months ahead of NASA’s previous schedule, an unusually early milestone for a flagship astrophysics mission after years of development.
Named after the late Dr. Nancy Grace Roman — NASA’s first chief astronomer who championed space telescopes — Roman is expected to transform astronomy in much the same way the Hubble Space Telescope did more than three decades ago. However, instead of producing exquisitely detailed close-up images of individual objects, it will create enormous panoramic maps of the universe.
Roman vs Hubble: A Wide-Angle View Of The Universe
Rather than studying one galaxy at a time, Roman will map billions of them, giving astronomers an entirely new perspective on how the universe is structured and how it has evolved over cosmic history. To do that, it carries the same 2.4-meter (7.9-foot) primary mirror as Hubble, but its Wide Field Instrument will capture images covering more than 100 times Hubble’s field of view, allowing it to survey vast areas of sky at speed. During its five-year prime mission, Roman is expected to collect around 20 petabytes of science data — and image more sky than Hubble has observed during decades of operations, according to NASA.
One month of Roman observations could survey our own Milky Way, resulting in the detection of up to half the stars in our own galaxy,” said Julie McEnery, Roman telescope senior project scientist, NASA Goddard, in a NASA press conference on July 29. “This would itself represent a catalog of astronomical objects much larger than any in existence today.” She added that it would take over half a million 4K TVs to fully display the single Roman image from its largest survey — enough to cover El Capitan in Yosemite National Park.
Looking For 100,000 New Worlds
Perhaps most exciting is Roman’s status as an exoplanet hunter. Unlike NASA’s Kepler and TESS missions that could only find planets that orbit close to their host stars, Roman is expected to discover 100,000 colder exoplanets orbiting far away — planets like most of those in our own solar system. That’s up to 40 times more than we know of today. It’s also likely going to find large populations of rogue planets drifting through the Milky Way without orbiting any star at all.
Finding ‘Needles In Haystacks’
“Roman’s vast reach will allow us to find the weird, the rare, and the unusual,” said McEnery, citing things like exoplanets with disks, isolated black holes and neutron stars in our galaxy, and runaway supermassive black holes. “We’ll redefine what it means to find a needle in a haystack.”
Roman will also carry a coronagraph, a disk to block the glare from a star, to help it photograph giant exoplanets. It’s hoped that it will prove out the tech for a future space telescope to photograph Earth-sized planets around nearby sun-like stars.
Mapping Dark Energy And Dark Matter
One of Roman’s goals is tackling one of modern astronomy’s biggest mysteries — why the universe’s expansion is accelerating. By mapping the positions of billions of galaxies, measuring subtle distortions caused by gravitational lensing (when one galaxy warps the light of another behind it) and observing thousands of supernovae, Roman will produce the most comprehensive measurements yet of dark energy — the mysterious force thought to drive the universe’s accelerating expansion. The hope is that astronomers will finally be able to see where dark matter is and how it’s spread across the cosmos.
The observatory will also investigate supermassive black holes, exploding stars, stellar nurseries, nearby galaxies, asteroids, comets and countless other cosmic phenomena.
Roman vs Webb: Working Together A Million Miles From Earth
Following launch on Aug. 30, Roman will travel to the sun-Earth L2 Lagrange point, which is about one million miles (1.5 million kilometers) from Earth, where it will join the James Webb Space Telescope. From there, the two observatories will work as complementary partners. Webb will continue examining individual galaxies, stars and nebulae in detail, while Roman surveys the vast cosmic landscape surrounding them, identifying the most intriguing targets for a closer look.
“Roman is poised to conduct revolutionary surveys that will impact every area of astronomy,” said McEnery. “We can do this because Roman’s primary instrument combines exquisite performance and sensitivity with the ability to quickly and efficiently survey large regions of the sky.”
Wishing you clear skies and wide eyes.