Since 2019, GPS signals across Europe, Greenland and Canada have experienced a huge spike in sudden, widespread signal blackouts. These have resulted in disruptions and degraded performance in navigation systems that airplanes and ships rely on to travel safely.

Some causes are known, such as military jamming on the ground, but others have been a total mystery. A new paper published on the arXiv preprint server points an accusatory finger at Russia, claiming that a constellation of Russian satellites is likely responsible for many of these interference events, which have been blasting out waves of radio static from space.

The study focuses on how these events affected the Global Navigation Satellite System (GNSS) that GPS relies on. The researchers studied 75 separate days on which at least one major interference event occurred.