A high-altitude telescope just changed what we know about black holes

A balloon drifting from Sweden to Canada last summer carried with it the most precise measurements ever taken of light waves spiraling away from one of space's most notorious monsters. The XL-Calibur telescope captured polarized X-rays from Cygnus X-1, a black hole 7,000 light-years away, revealing new details about how these cosmic giants devour surrounding material while simultaneously blasting tremendous amounts of energy into space.

Scientists can't photograph black holes directly from Earth, so they rely on studying the orientation of electromagnetic vibrations in the light streaming from the superheated debris swirling around them at extreme speeds. "If we try to find Cyg X-1 in the sky, we'd be looking for a really tiny point of X-ray light," explained graduate student Ephraim Gau. "Polarization is thus useful for learning about all the stuff happening around the black hole when we can't take normal pictures from Earth."

The international team plans to launch their balloon-borne telescope from Antarctica in 2027, aiming to solve longstanding mysteries about how matter behaves in these extreme cosmic environments.