Radio signal from a rocky planet increases chances of discovering habitable worlds

An international research team has discovered a possible rocky, Earth-like exoplanet (or exoplanet) called YZ Ceti b could have a magnetic field. It is the first time that scientists have made a discovery of this type and it is very significant. In fact, a magnetic field represents a “shield” for the atmosphere and life itself on a planet, protecting the cosmic and stellar radiation capable of destroying them. This is exactly what happens on Earth: if the magnetic field were not there, in fact, the plasma of the solar wind – the electrically charged particles ejected from the Sun – and other UV radiation would destroy the ozone layer and reach the surface, killing all biological forms in it (humans included). In short, knowing that a rocky exoplanet could possess this “defense system” is exciting news.

To discover the possible magnetic field in the exoplanet YZ Ceti b, a “subterranean 12 light years from us, nestled in the constellation of the Whale, were the two scientists J. Sebastian Pineda and Jackie Villadsen, respectively from the Laboratory of Atmospheric Physics and Space Science from the University of Colorado at Boulder and the Department of Physics and Astronomy. from Bucknell University. The two academics surveyed the planet with the Karl G. Jansky Very Large Array radio telescope, picking up a repeating radio signal similar to that of polar auroras. It is no coincidence that they called it “auroral radio emissions”. These luminous phenomena, such as those that recently appeared over the skies of New Zealand, arise precisely from the interaction between the particles of the solar wind and the gases present in the ionosphere, distributing themselves along the lines of the earth’s magnetic field and giving life to the wonderful auroral arcs. The researchers believe that the stellar radio waves detected in the YZ Ceti system derive precisely from interactions between the rocky exoplanet’s magnetic field and the activity of its star.

“The search for potentially habitable or life-bearing worlds in other solar systems depends in part on being able to determine whether rocky, Earth-like exoplanets actually have magnetic fields,” said NSF Program Dr. for the National Radio Astronomy Observatory. “This research not only shows that this particular rocky exoplanet likely has a magnetic field, but provides a promising method for finding out more,” he added. The two researchers zeroed in on YZ Ceti b because it orbits very close to its star and takes only two days to complete one orbit (in other words, a year on this alien world lasts a mere 48 Earth hours). This allows scientists to quickly and repeatedly analyze the interaction phenomena between the two celestial objects. According to the two academics, the research is providing “new information about the environment around stars”, what is called “extrasolar space weather”. Since magnetic fields are invisible (in the absence of a bright aurora), refining these detection techniques could one day allow us to discover a potentially habitable exoplanet complete with a magnetic field, a detail that would dramatically increase the chances that it could harbor life forms. . and can even be colonized. However, this is not the case for YZ Ceti b, which, orbiting very close to the parent star, is outside the so-called Goldilocks zone – the one that theoretically allows liquid water on the surface, and is characterized by hellish temperatures. Details of the research “Coherent radio bursts from the well-known dwarf planet M-host YZ Ceti” have been published in the prestigious scientific journal Nature.