Fast Radio Bursts (FRBs) are extremely powerful energy impulses originating from the most distant regions of the universe, yet their exact scientific explanation remains elusive. These bursts can release as much energy in a millisecond as the Sun emits over three days. Researchers have proposed several theories regarding their source, with one popular hypothesis suggesting that FRBs result from collisions between neutron stars and other neutron stars or even black holes.
However, a team led by Dan Fama from the University of Toronto has introduced a radical new hypothesis. In a study published in the Astrophysical Journal, they propose that these bursts may be caused by asteroids colliding with neutron stars.
According to their calculations, the frequency of asteroid collisions with neutron stars aligns with the predicted number of bursts observed in the universe. Fama noted, “It has long been known that such collisions could cause fast radio bursts, but it was previously unclear whether they occur frequently enough to explain the observed rate of these phenomena.”
Previous estimates suggest that there may be up to ten trillion interstellar objects, such as 'Oumuamua and Comet Borisov, within the Milky Way. Approximately one billion neutron stars are known to exist in our galaxy. Based on this data, the research team calculated that one collision occurs every 10 million years for each neutron star, matching the observed frequency of FRBs.
When an asteroid or comet strikes the magnetic field of a neutron star, it vaporizes instantly and accelerates to speeds close to that of light. The resulting plasma sphere moves along the magnetic field, creating a beam of radiation that could be the source of the burst.
Matthew Hopkins, an astrophysicist at the University of Oxford, explained that the energy of such bursts depends on the size of the asteroid and the strength of the neutron star's magnetic field. For instance, an asteroid just over one kilometer in diameter could release energy equivalent to 100 million times that used by humanity in a year.
If this hypothesis is correct, the occurrence of FRBs may increase with the age of the universe. Additionally, some FRBs have been observed to occur repeatedly at regular intervals from the same source, which does not entirely align with the probabilistic nature of collisions between neutron stars and asteroids. Nevertheless, the collision hypothesis remains an intriguing avenue for further research as observations and data analyses continue.