NASA’s New Roman Telescope Will Map The Milky Way In Unprecedented Detail
There's going to be a new space telescope in town: the Nancy Grace Roman (the famous NASA astronomer, not to be mistaken for the crime show host), which is slated to launch by May 2027. At least initially, its main mission will be to chart the nature of dark energy and the hidden structure of our own Milky Way galaxy.
As many of us already know, the universe contains giant, sprawling regions where matter is remarkably sparse. These areas, known as cosmic voids, are key to understanding the universe's ultimate fate. Voids can span hundreds of millions of light-years, forming the empty interiors of the cosmic bubbles. Because they are relatively empty of normal and dark matter, void regions are dominated by the mysterious force known as dark energy, which is currently accelerating cosmic expansion.
By studying the precise shapes and sizes of tens of thousands of these voids, Roman will help astronomers constrain cosmological models, testing how dark energy has evolved over time. This process is akin to trying to adjust the theoretical ingredients of matter and dark energy until the resulting void shapes match what Roman observes. To accomplish that and gather the necessary data, the telescope's High-Latitude Wide-Area Survey will cover an immense 2,400 square degrees of the sky, far beyond the capability of existing missions.
Closer to home, Roman will turn its infrared eye toward the dense plane of the Milky Way. Our position inside the galaxy has historically made studying the galactic center and far side difficult, as thick bands of interstellar dust obscure visible light. Roman’s infrared capabilities, combined with a field of view 200 times greater than even Hubble's, are designed to pierce this veil.
The ambitious Galactic Plane Survey, scheduled to take only 29 days (spread over the mission’s first two years), will map up to 20 billion stars across nearly 700 square degrees of the galactic disc. This survey has the potential to not only unveil previously unseen structures but also create detailed 3D dust maps. Furthermore, repeated high-resolution imaging will allow scientists to study stellar birth and evolution in unprecedented detail, capturing millions of stellar embryos, tracking the evolution of young stars, and observing compact, invisible objects like isolated black holes via gravitational microlensing.
While the Nancy Grace Roman telescope is scheduled for a May 2027 launch onboard a SpaceX Falcon Heavy, the telescope's team is pushing for a Fall 2026 date instead.
