Evrim Yazgin
Cosmos science journalist
The NASA team behind the Nancy Grace Roman Space Telescope – due to launch in 2027 – have shared the designs for the mission’s 3 core surveys.
Roman will deepen understanding into the mysteries of astrophysics and the universe.
“Roman’s setting out to do wide, deep surveys of the universe in a way that will help us answer questions about how dark energy and dark matter govern cosmic evolution, and the demographics of worlds beyond our solar system,” says Gail Zasowski, an associate professor at the University of Utah, US, and co-chair of the Roman Observations Time Allocation Committee (ROTAC).
But, Zasowski says, the main goal of the mission is to provide space researchers with new data and tools to delve into different areas of scientific investigation.
Roman will have a detailed, panoramic view of space. Its field of view will be 100 times greater than that of the Hubble Space Telescope.
The 3 survey designs will account for up to 75% of Roman’s investigations in its 5-year primary mission. The rest of Roman’s time allocation will be given to additional observations proposed and developed by the broader astronomical community.
“These survey designs are the culmination of two years of input from more than 1,000 scientists from over 350 institutions across the globe,” says Julie McEnery, Roman’s senior project scientist at NASA Goddard. “We’re thrilled that we’ve been able to hear from so many of the people who’ll use the data after launch to investigate everything from objects in our outer solar system, planets across our galaxy, dark matter and dark energy, to exploding stars, growing black holes, galaxies by the billions, and so much more.”
The largest of the 3 surveys is the High-Latitude Wide-Area Survey which will be used to unveil more than a billion galaxies across the lifetime of the universe.
The distribution and shape of galaxies revealed by Roman will help explain the nature of dark energy – the mysterious phenomenon that cosmologists believe is behind the accelerating expansion of the universe.
Roman’s High-Latitude Time-Domain Survey will observe the same region of the universe to show how the universe changes over time. Scientists will be able to study how objects like galaxies and stars change over days, months and years.
“Staring at a large volume of the sky for so long will also reveal black holes being born as neutron stars merge, and tidal disruption events – flares released by stars falling into black holes,” says ROTAC co-chair Saurabh Jha, a professor at Rutgers University in New Brunswick, US. “It will also allow astronomers to explore variable objects, like active galaxies and binary systems. And it enables more open-ended cosmic exploration than most other space telescopes can do, offering a chance to answer questions we haven’t yet thought to ask.”
Unlike the other 2 surveys, the Galactic Bulge Time-Domain Survey will not look out, but directly into the centre of our own Milky Way galaxy.
This deep, detailed view at our galactic home’s heart will allow astronomers to watch hundreds of millions of stars in the Milky Way, including those harbouring habitable worlds with potential to host life.
Observations from this survey can also be used to study unusual stellar phenomena like “rogue planets” drifting through space and stellar corpses like neutron stars and white dwarfs.
“Roman’s unprecedented data will offer practically limitless opportunities for astronomers to explore all kinds of cosmic topics,” McEnery says. “We stand to learn a tremendous amount of new information about the universe very rapidly after the mission launches.”
