Unexplained radio signals received in Antarctica between 2016 and 2018 continue to puzzle scientists. These anomalous radio bursts were recorded using a NASA balloon equipped with the ANITA antenna system. Interestingly, these signals appeared to originate from beneath the ice and move upward, contrary to all known physical laws.
The ANITA mission was originally aimed at studying cosmic rays, focusing on the radio waves generated during their interaction with the atmosphere, according to Science XXI. However, some of the recorded signals exhibited unusually steep angles, about 30 degrees below the ice cover. This discovery sparked speculation about the existence of new elementary particles. To test these hypotheses, an international team of researchers conducted an analysis, comparing ANITA data with information from the Pierre Auger Observatory over the past 15 years.
Attempts to decipher the nature of these signals have been unsuccessful. The main hypothesis regarding neutrinos has not been confirmed. From a theoretical standpoint, a special type of neutrino could cause a cascade of particles when interacting with ice, which detectors would capture. However, the recorded signals had too steep an angle, which did not match the predictions of the models. Furthermore, independent detectors, such as the IceCube Observatory, did not register similar phenomena, ruling out neutrinos as potential sources.
Interestingly, for the signal to reach the detector, it would have to traverse thousands of kilometers through ice and rock, which typically leads to its complete absorption. The lack of confirmations from other observatories has also prompted scientists to reconsider their initial theories regarding the anomaly's connection to dark matter or new physics. At present, this phenomenon is classified as "anomalous," and its source remains unknown.
Meanwhile, researchers are hopeful for a new, more powerful and sensitive detector called PUEO, which is being developed for further study of similar signals. Scientists suggest that its launch could help clarify the nature of the mysterious radio signals from Antarctica. One of the current theories is that the anomaly may be caused by some interesting yet unexplored effect of radio wave propagation near the ice surface.
