Scientists, including cosmologist and NASA advisor Paul Sutter, are proposing a crazy idea: turn the Sun into a giant telescope using the gravitational lensing effect. This phenomenon, predicted by Albert Einstein in his general theory of relativity, allows light from distant objects to circle a massive body like the Sun and focus at a point 542 astronomical units (a.u.) away from Earth – about 81 billion kilometers. Such a telescope could produce detailed images of exoplanets such as Proxima b with a resolution of up to one kilometer, a million times greater than current instruments such as the Event Horizon Telescope. This would make it possible to see coastlines, weather systems and even traces of vegetation, if they exist, on exoplanets.
Gravitational lensing is already being used extensively in astronomy. It helps amplify light from distant galaxies, black holes, and other objects behind massive galaxy clusters that act as natural lenses. The Sun, as the most massive object in our system, is ideal for this role, creating a focal point with an incredible angular resolution of about 10^-10 radians. However, the main difficulty lies in the distance: 542 a.u. is 13 times farther than Pluto’s orbit and more than three times farther than the current position of the Voyager 1 probe, the most distant spacecraft. By comparison, current technology allows probes such as Voyagers to reach such distances in decades, but they are unable to maneuver or collect complex data under such conditions.
The realization of the project requires significant technological breakthroughs. A maneuverable probe or fleet of small cubesats equipped with solar sails that use the pressure of sunlight to accelerate must be built. Such vehicles could reach a focal point in 20 to 30 years and operate in swarms, scanning the area for images. Highly efficient solar arrays, long-range data transmission systems, and algorithms to coordinate the swarm of satellites are also required. Despite these challenges, scientists including Sutter believe the idea is feasible. “It’s so crazy that it could work,” he emphasizes. If the project succeeds, humanity will have a tool that could rewrite our understanding of the cosmos, from maps of exoplanets to the study of the early universe.
