The pulsar in the Crab Nebula blinks like a lighthouse: every 33 milliseconds it sends out a radio pulse, and it does so with the precision of atomic clocks. But sometimes its rotation stumbles: the star suddenly speeds up slightly, as if something inside it is shifting. Such glitches were thought to be random, like the ticks of a metronome that occasionally gets nudged.
Astronomers gathered years of data and saw that small glitches are not scattered haphazardly. They bunch together — series of several glitches in a row. Between these clusters there are pauses, and the longer the pause, the larger the next cluster. This is like a reservoir: inside the star there is a store of rotation that builds up and then releases in bursts.
In June 2025, scientists predicted that a new series of glitches would soon begin. And indeed, two small glitches occurred in July and August. Now they expect a major glitch by August 2026—one that will change the star's rotation frequency by a noticeable amount.
This discovery changes our view of pulsars. Previously, glitches were thought to be pure randomness. Now it is clear that there is a long-term rhythm inside the star, like a spring that alternately stores and releases energy. And this rhythm can be read from the clusters of glitches, like a schedule.
The pulsar in the Crab Nebula spins 30 times per second, and its glitches are so tiny that they change the rotation period by one billionth of a second.
The idea of predictable cosmic events echoes Stanisław Lem's novel "Solaris," where the planet's ocean behaves according to an incomprehensible but not random logic.