A New Study Suggests that a Missing Component of the Universe may be Present in Earth’s High Atmosphere
New theoretical research suggests that we may be swimming in an ocean of dark matter, with waves from that invisible ocean crashing into our planet’s upper atmosphere producing detectable radio waves that could lead us to the ultimate discovery of this elusive element of the universe.
From the emergence of the greatest structures in the universe to the unexplained rotation curves of some galaxies, a plethora of astrophysical and cosmological data suggests the existence of dark matter. The great majority of astronomers believe dark matter is some unidentified form of matter that interacts with light or normal matter very infrequently because attempts to explain this wide range of findings with different formulations of gravity have failed.
However, that’s a rather wide concept that covers a lot of ground. Massive particles could make up dark matter, but most searches for them have produced no results. Thus, a fascinating alternate explanation for dark matter might be that it is incredibly light, either as hypothetical particles called “axions” or as a unique type of photon that has some mass.
Dark matter could function in extremely odd ways because of its extraordinary lightness—it is millions of times lighter than the lightest known particles. In instance, the dark matter would act more like big waves that swirl around the universe rather of seeming as discrete point-like shots.
Scientists recently investigated models of ultralight dark matter that were partially dark, enabling very infrequent interactions with normal matter, and posted their findings to the preprint server arXiv. For the most part, these exchanges produced no noticeable results and hardly registered at all. But occasionally, there was enough interaction between the dark matter and normal matter to generate a significant amount of radio waves.
This is what would happen if dark matter collided with plasma and its wave frequency coincided with that of the plasma. The team’s simulations predicted that when this occurred, a resonance would take place, intensifying the interaction and generating radiation in the form of radio waves.
Since all stars release plasma into space in the form of stellar wind, the cosmos is no stranger to plasma; therefore, theorists have already investigated the possibility that dark matter interacting with environments like the solar corona or the interstellar medium could produce radio waves. However, the ionosphere of our planet—a much closer-in interaction point—was found by the scientists in this recent study.
The thin, hot layer of Earth’s upper atmosphere is called the ionosphere, and it is made up of a loose assembly of charged particles known as plasma that have been ionized. The waves that flow through it naturally can interact with waves of hypothetical dark matter that may be washing over Earth, the researchers found.
This interaction would emit radio waves that are hardly noticeable. However, the researchers discovered that they might be able to find these waves if they used a precisely calibrated radio antenna to look for a certain frequency of radio waves over the course of a year.
This concept is particularly interesting because Earth’s ionosphere provides a number of benefits over alternative sources of radio waves generated by dark matter. One reason is that the ionosphere is largely free of polluting transmissions because it naturally reflects a large number of radio waves from deeper space. Second, the ionosphere is easily accessible, directly overhead, and already the focus of ongoing research and observation.
It’s unlikely. It would take years, if not decades, to refine the observation technique to look for these radio waves, and this type of dark matter is very theoretical. However, if successful, it would be a treasure trove that would enable us to investigate one of the universe’s most enigmatic components at our cosmic doorstep.