Earth may be floating in an ocean dark matter – and waves in this invisible ocean hitting our planet’s upper atmosphere may generate detectable radio waves, allowing us to finally find this elusive component of the universe, according to new theoretical research.
A wealth of astrophysical and cosmological evidence points to the existence of dark matter, from the unexplained rotation curves of certain galaxies to the growth of the largest structures in the universe. Attempts to explain this wide range of observations with alternative formulations gravitation they failed, so the vast majority of astronomers think dark matter is some unknown form of matter that rarely interacts with light or normal matter.
But that’s a very broad idea that covers a lot of possibilities. Dark matter they can be made of massive particles, but the search for these kinds of particles has largely come up empty. So an interesting alternative is that dark matter is exceptionally light, either in the form of theoretical particles known as “axions” or as an exotic form of photon that carries some matter.
With that incredible lightness—millions of times lighter than the lightest known particles—dark matter could act in very strange ways. In particular, dark matter would appear instead of appearing as individual bullet points they behave more like big waves that thrash around in space.
IN recent studies Publishing on the preprint server arXiv, physicists explored models of ultralight dark matter that was not completely dark, allowing it to interact extremely rarely with normal matter. Most of the time these interactions barely registered and produced nothing detectable. But in rare cases, dark matter and normal matter have interacted enough to produce significant amounts radio waves.
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This happens when dark matter meets sa plasma and when the frequency of dark matter waves matched that of plasma waves. When that happens, a resonance occurs that strengthens the interaction and creates radiation in the form of radio waves, the team’s models suggested.
The universe is no stranger to plasma – all stars spew plasma into space in the form of stellar winds – so theorists have already explored the production of radio waves due to the interaction of dark matter with environments such as the solar corona or the interstellar medium. But in this new research, scientists have discovered an interaction point much closer to home: our planet’s ionosphere.
The Earth’s ionosphere is a thin, hot layer of the upper atmosphere and consists of a loose cluster of ionized (charged) particles – plasma. Waves naturally penetrate it, and researchers have found that these waves can interact with waves of hypothetical dark matter that could be orbiting Earth.
The radio waves produced by this interaction would be barely detectable. But scientists have found that by using a carefully tuned radio antenna to look for a specific frequency of radio waves throughout the year, they might be able to detect those waves.
This idea is particularly promising because the Earth’s ionosphere offers several advantages over other sources of radio waves produced by dark matter. First, the ionosphere naturally reflects many radio waves from deeper space, so it is relatively free of contaminating signals. Second, the ionosphere is directly above us, easily accessible, and already the subject of constant observation and study.
It’s a long run. This form of dark matter is highly theoretical and it would take years, if not decades, to perfect the observational technique to search for these radio waves. But if it works, it would be a gold mine, allowing us to study one of the most mysterious elements in the universe right on our cosmic doorstep.