Using gravitational lensing, it might be possible to utilize the sun as a gigantic telescope to observe deep into space. We’ve already built powerful observatories like the James Webb Space Telescope (JWST) that allow us to view distant galaxies and early cosmic history. But imagine if we could access an even more powerful telescope without constructing anything new — using the sun itself.
The sun’s immense mass bends space-time, and light that passes near it is deflected toward a focal point, creating a natural telescope. This phenomenon, known as gravitational lensing, is already used by astronomers to study distant galaxies. By placing an instrument at the sun’s focal point, we could observe the universe at an unprecedented resolution — far beyond the capabilities of current technology.
The potential resolution of a “solar gravitational lens” would be extraordinary, about a million times more powerful than the Event Horizon Telescope, which imaged black holes. However, reaching this focal point presents challenges. It lies 542 times farther than the Earth-sun distance, 11 times farther than Pluto. A spacecraft would need to travel farther than ever before, maintain fuel, and scan large areas to capture complete images.
Plans to leverage the solar lens date back to the 1970s. Recently, astronomers have proposed launching a fleet of small cubesats with solar sails to reach this distant point. Once there, we could achieve breathtaking observations, such as imaging exoplanets like Proxima b with 1-kilometer resolution, offering surface details unimaginable with today’s telescopes.
In essence, this “supertelescope” would surpass anything we could build for centuries. The technology already exists — we just need to get a camera in the right place.
