An ambitious plan to test extreme physics close to a black hole would involve a space probe weighing only a few grams, travelling at a third of the speed of light
By James Woodford
7 August 2025
An illustration of a spaceship sailing close to a black hole
liuzishan/Getty Images
An interstellar probe sent to a black hole could complete its journey and send data back to Earth in less than a century – if we can find a black hole close enough.
Cosimo Bambi at Fudan University in Shanghai, China, has developed a blueprint for such a mission, using technology that may be available in the next 20 to 30 years.
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Getting up close to a black hole would allow us to test Albert Einstein’s theory of general relativity and reveal what happens to the fundamental constants of physics in an extreme gravity field.
The closest known black hole to us is about 1500 light years away, much too far for us to send a craft there. But in the Milky Way, there is thought to be roughly one black hole for every 100 normal stars. That means there is likely to be a black hole somewhere within 20 to 25 light years of us, says Bambi.
Spotting one, however, will be tricky. As black holes don’t emit light, astronomers must detect them by observing their effects on stars or how they distort light.