American researchers have discovered another criterion that will help to understand whether the exoplanet is suitable for life or not, coronal mass ejections (CME).
Traditionally, an exoplanet can be considered “fit for life” if its orbit corresponds to the temperature at which water can exist in the liquid state. However, researchers at Boston University found that this may not be enough, and called a new criterion for life on exoplanets – coronal mass ejections (CME).
Coronal mass ejections are huge explosions of plasma and magnetic fields from the solar corona or other stars. They are a fundamental factor in the so-called “space weather” and can destroy satellites and other electronic equipment on Earth.
American researchers have proved that the impact of “space weather” can also have a significant impact on the potential habitability of low-mass exoplanets. They also found out that the coronal mass ejections “squeeze” the magnetosphere of the exoplanet, and in some cases can even exert sufficient pressure to destroy its atmosphere.
The team at Boston University, led by researcher Christine Kay, simulated the trajectory of coronal mass ejections from the cold star V374 Pegasi and found that strong magnetic fields displaced them to a current layer-the surface at which the polarity of the magnetic field changes.
This means that an exoplanet will require a magnetic field tens of thousands of times greater than that of the Earth to protect its atmosphere from coronal mass ejections. Thus, the search for life-threatening exoplanets is complicated, the researchers conclude.
