NASA’s next “great observatory” begins mission to widen our view of the Universe

Roman’s Wide Field Instrument gives the observatory its broad vision. This near-infrared camera can take a picture of a pocket of the sky larger than the full Moon, allowing Roman to map megastructures like clusters of galaxies and large-scale filaments of matter and dark matter that make up the cosmic web.

“To put it into perspective, it is as if Hubble and James Webb kind of peered through a keyhole at the Universe, while Nancy Grace Roman will kick the door down,” Fox said. “But Roman isn’t just doing Hubble and Webb science faster. It’s doing fundamentally different science that could not be done by either observatory. Together, these three flagship telescopes will combine their observations to give us a more complete picture of our cosmos, and our place in it.”

A second instrument on Roman, called a coronagraph, will allow astronomers to directly image planets orbiting faraway stars in our own galaxy. The coronagraph works by blocking the bright light from stars, using masks and large-format self-flexing mirrors to detect planets 100 million times fainter than their hosts. NASA says the coronagraph on Roman, with internal mirrors capable of adjusting their prescription on the fly, is 100 to 1,000 times more sensitive than previous coronagraphs on Webb and Hubble.

This part of Roman’s toolkit will allow astronomers to study the sizes, atmospheres, and structures of more kinds of exoplanets than possible today. The coronagraph’s innovations will inform the design of future instruments that could expand the reach of direct imaging to include rocky planets in the habitable zones of their stars.

“Roman will photograph worlds, dusty disks, and nearby stars in visible light to help see the giant worlds that are older, colder, and in closer orbits than the hot young Jupiters that we’ve previously imaged with other telescopes,” Fox said.

Roman will also detect exoplanets using the tried-and-true transit method, but scientists expect the new telescope will find a lot more than past space missions have, thanks to its wider vision.

Heigh-ho, it’s off to work we go

All of this means data, and lots of it.

“In just one day of observing our Universe, Roman will downlink 1.4 terabytes of data,” Fox said. “That is an entire gaming system hard drive in one day. That is a staggering amount of data.”

Roman will transmit this amount of information down to Earth nearly every day for its planned five-year mission. NASA and its partners will connect with Roman through a collection of ground stations around the world separate from the agency’s oversubscribed Deep Space Network. NASA and the Space Telescope Science Institute, which oversees Roman’s operations, will release the observatory’s data to a public archive accessible to scientists around the world.