Magnetic fields play a crucial role in creating habitable planets, protecting them from energetic particles from stars that can strip away their atmosphere, rendering them unsuitable for life. Earth is known to possess a magnetic field that provides various benefits, such as shielding the planet from the sun’s harmful rays and the creation of beautiful auroras. Similarly, other planets in our solar system also have magnetic fields, but scientists have long questioned whether Earth-like planets in other star systems possess magnetic fields.
A recent discovery may provide a promising lead in answering this question. Using the Very Large Array radio telescopes in New Mexico, astronomers detected evidence of a magnetic field on YZ Ceti b, a rocky exoplanet located 12 light-years away from Earth. This discovery marks the first possible detection of a magnetic field on an exoplanet, according to a study published in the journal Nature Astronomy on April 3.
Although YZ Ceti b is not a habitable planet, its proximity to its star allowed astronomers to detect radio waves from its magnetic field. The planet orbits too close to its star, and one year on YZ Ceti b is just two Earth days long. As a result, the planet “plows” through the star’s material, and its magnetic field pushes electrically charged plasma back toward the star, creating bright flashes of energy when it interacts with the star’s own magnetic field. The radio waves observed were likely an aurora on the star, created through interactions with the planet, according to the researchers.
While YZ Ceti b is not habitable, its discovery provides a promising lead in identifying magnetic fields on Earth-like planets in other solar systems. The search for potentially habitable worlds in other solar systems depends on determining whether rocky, Earth-like exoplanets have magnetic fields. Planets lacking a magnetic field are vulnerable to energetic particles from a star that can strip away their atmosphere, rendering them unsuitable for life.
The discovery of a potential magnetic field on YZ Ceti b could lead to more discoveries of magnetic fields on other Earth-like exoplanets in the future. It also provides new information about the environment around stars and the concept of “extrasolar space weather.” Further observations are needed to confirm whether the stellar aurora is entirely caused by YZ Ceti b and not just a feature of the star itself. However, the researchers remain optimistic that these findings could lead to breakthroughs in the search for habitable alien planets.
