Since its discovery in February 2017, the TRAPPIST-1 solar system has frequently been under focus. At first, it seemed that this 39 light-years-far system could house extraterrestrial life. Then came the bad news that there might be too much water to sustain life. Now, finally, a very good news emerged that TRAPPIST-1e exoplanet might have a dense metal core, meaning that it could have a magnetosphere, one of the necessities for life to evolve.
The discovery of the star TRAPPIST-1 and its seven planets was such fascinating because most of these exoplanets stars are located in the Goldilocks zone, an astronomical colloquial term used to designate that a star’s temperature is ideal for liquid water to exist.
TRAPPIST-1 is a brown dwarf of type M
Being a type M star, TRAPPIST-1 is less luminous than our Sun (a type G) and therefore for a TRAPPIST exoplanet to sustain life it has to be close to its star.
However, the exoplanets in this system suffer from the tidal coupling, an effect by which their rotation period and translation period are equivalent, which means that one of the faces is permanently exposed to the Sun, which is very bad news for habitability.
Another problem would be that this proximity makes planets more susceptible to solar flares and magnetic storms.
TRAPPIST-1e exoplanet presents a dense metal core
A team of astronomers from the Columbia University has concluded that TRAPPIST-1e has a dense core, probably metallic in composition, very similar to that of our own planet.
A dense core, under any probability, is the engine of a powerful magnetosphere that should protect the planet’s surface from solar flares.
To achieve such a conclusion, scientists compared the very accurate readings regarding the mass and the radius of the TRAPPIST-1e exoplanet with the theoretical models of the internal structure of planets using their own algorithms.
TRAPPIST-1e presents a core radius of between 50 and 78% of the total radius of the planet. The Earth, to make a comparison, has a core that accounts for 55% of the planet’s mass. The scientists concluded that TRAPPIST-1e must have a dense metal core, therefore, a magnetosphere, so it could house life.