High-energy electrons captured over Antarctica could reveal the presence of a nearby but mysterious astrophysical object that’s bombarding Earth with cosmic rays, researchers say. Or the electrons may be the long-awaited physical evidence of elusive dark matter.

Either way, the unusual particles are exciting for astrophysicists, who say they could someday confirm or deny decades of unproven theories. “In the first case, we have now seen for the first time a nearby source of cosmic rays.
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Cosmic rays are not beams per se but are any protons, electrons, and other subatomic particles that careen toward Earth from a variety of sources, including the supernova explosions that mark the deaths of stars.

Most of the cosmic electrons that reach Earth are low-energy, because the highest-energy ones fizzle the fastest and don’t last long enough to get here.