Technology news | Space telescopes

Hubble observations prepare the way for Roman

NASA's November 12, 2026 feature highlights a collection of gravitational lenses imaged by the Hubble Space Telescope. The observations are useful both for studying the lenses now and for developing ways to find similar objects in the much larger surveys planned with the Nancy Grace Roman Space Telescope.

Published: 12 November 2026Source: NASA

Space acts like a lens

When a massive foreground galaxy lies between us and a more distant galaxy, its gravity bends the background galaxy's light. Under the right alignment, the background object appears as arcs, duplicated images, or an almost complete ring. This effect is called gravitational lensing.

By measuring the shapes of these distorted images, astronomers can model the foreground system's mass, including matter that does not emit light. Lensing is one tool for investigating dark matter, but a lens image alone is not a direct photograph of dark matter.

Different telescopes, complementary jobs

Hubble's sharp view lets researchers examine individual lenses in detail. Roman is designed to survey a much wider area of sky, primarily in infrared light, and is expected to find many more lens candidates. A useful workflow is to search the broad Roman survey for interesting examples, then use Hubble or other instruments for focused follow-up observations.

NASA's report also describes using the Hubble images to develop a machine-learning tool that can help identify lens-like arcs in Roman data. The aim is to make the large search more efficient; researchers still need to inspect candidates, compare them with models, and test what the evidence supports.