The observable universe contains up to two trillion galaxies, which are not randomly scattered but instead form giant cosmic “bubbles” separated by mostly empty regions called cosmic voids.

NASA’s Nancy Grace Roman Space Telescope will map these voids with unprecedented precision, helping scientists study the universe’s expansion and the mysterious roles of dark matter and dark energy.

By combining galaxy positions and spectroscopic redshifts, astronomers can reconstruct the 3D shapes of voids and use statistical methods—stacking tens of thousands of voids—to refine models of the universe’s composition.

The Roman High-Latitude Wide-Area Survey will cover a vast portion of the sky, detecting faint, sparse galaxies within voids and providing higher galaxy density data than missions like ESA’s Euclid, NASA has reported.

Studying voids in this way will offer critical insights into how dark energy and matter influence the cosmos, much like deducing a “recipe” from the final structure of the universe.