Introductory Paragraph:
High above the frozen expanse of Antarctica, a balloon-borne experiment was supposed to observe cosmic rays falling from space.
But what it found instead stunned physicists: signals rising from beneath the ice, seemingly originating from deep within the Earth. These detections defied explanation, challenged existing models, and triggered a years-long scientific investigation that remains unresolved to this day.
The 2006 and 2014 ANITA Events
In 2006, NASA’s Antarctic Impulsive Transient Antenna (ANITA) recorded a sharp burst of radio waves from below the ice—something expected only if a particle had traveled up through Earth’s interior. A similar event was detected again in 2014.
Both looked like reversed cosmic ray showers, not reflections, but actual upward-emerging signals. The angle of entry, around 30 degrees from below, complicated the case for standard particle interpretations.
The Neutrino Hypothesis Falls Short
Tau neutrinos can interact with rock and ice to produce particle showers, but explaining both events this way proved problematic. No coinciding supernova was linked to the 2006 signal, and while a potential supernova matched the 2014 event, it was not definitive.
Further, the angle of emergence would require improbable paths through dense rock. Billions of neutrinos pass harmlessly through us every second, but detection only happens if one rarely interacts—which makes these steep-angle detections highly unusual.
Search for Confirmation Yields Nothing
Researchers turned to the Pierre Auger Observatory in Argentina. Its vast array and extensive cosmic ray records from 2004 to 2018 were examined for similar upward-moving events.
None were found. While the null result ruled out neutrinos as a source, it did not reveal what the real source might be. It simply narrowed the possibilities.
Looking to the Future With PUEO
ANITA’s final flight was in 2016, but a follow-up mission is already planned. The Payload for Ultrahigh Energy Observations (PUEO) is designed to have greater sensitivity and broader coverage.
Scientists hope it will detect more of these anomalies or identify their nature. The mystery persists: what emerged from deep under the Antarctic ice to trigger those brief, unexplained radio pulses remains unknown.
While scanning for cosmic rays above Antarctica in 2006, NASA’s balloon-borne ANITA experiment detected something no one expected:
radio signals rising from beneath the ice.
The bizarre discovery hinted at particles emerging from deep inside the Earth…🧵👇 pic.twitter.com/ek1sPTGgB9
— Detective Tiger’s Stories (@TigerDetective) June 18, 2025