NASA is working on a way to map continents on planets orbiting other stars. The technique, called optical very long baseline interferometry, or optical VLBI, would combine light from multiple space telescopes to create images sharp enough to see landmasses on distant worlds.
A telescope network that acts like a giant lens
The idea comes from physicist Paul Stankus, who won a NASA Innovative Advanced Concepts (NIAC) Phase I fellowship in 2026 to develop it. Optical VLBI would use two or more small space telescopes flying in precise formation. By linking their light signals, the system would mimic a single telescope hundreds of miles wide. That kind of resolving power could reveal surface features on exoplanets, including continents, oceans, and cloud patterns.
Current exoplanet imaging can barely detect a planet as a dot of light. Even the most powerful telescopes cannot resolve surface details. Stankus and his team at the University of Arizona believe optical VLBI could change that. The concept builds on radio VLBI, a technique already used on Earth to image black holes by linking radio telescopes across the globe. Optical VLBI would do the same thing but with visible light, which is much harder to coordinate.
Why local scientists and engineers care
The project is based in the United States, where NASA funds early stage research through NIAC. The program supports high risk, high reward ideas that could transform space exploration. For researchers, optical VLBI offers a path to answer a fundamental question: do other planets have continents like Earth? The answer could reshape how scientists think about planetary formation and the potential for life elsewhere.
Stankus and his collaborators will spend the next nine months studying the feasibility of the concept. They need to solve major engineering challenges, including keeping multiple spacecraft aligned within nanometers and combining their light without losing signal. If the Phase I study succeeds, the team could apply for Phase II funding to begin hardware development.
A long shot with enormous payoff
Optical VLBI for exoplanet imaging remains a theoretical concept. No one has ever built a space based optical interferometer of this scale. But NASA has a history of turning far fetched ideas into working missions. If the technology matures, it could give humanity its first look at the geography of alien worlds. For now, the work is just beginning.
