A set of new studies sheds light on the properties of the TRAPPIST-1 planetary system that is considered the most optimal candidate for finding biological life outside of our solar system.
The recently published studies in the journals Nature Astronomy and Astronomy and Astrophysics shed light on the TRAPPIST-1 star system, and offer new insight into the planets' composition.
The new studies suggest the tightly-packed planets located some 40 light years from Earth are the best chance of discovering alien life. Ever since the planets were discovered, scientists have been studying the star system to understand what the planets are like on their surface.
Now, the recently published studies suggest that the planets orbiting TRAPPIST-1have great potential to host lie, although researchers caution they are 'far from establishing' this for certain.
The TRAPPIST-1 planetary system is made up of seven planets (b, c, d, e, f, g, h) that orbit around the star and, although scientists argue their composition rocky, they are not sterile rocky worlds.
"We now know more about TRAPPIST-1 than any other planetary system apart from our own," said Sean Carey, manager of the Spitzer Science Center at Caltech/IPAC in Pasadena, California, and co-author of the new study. "The improved densities in our study dramatically refine our understanding of the nature of these mysterious worlds."
Based on the analysis of how starlight interacts with the planets' atmospheres, scientists concluded that all seven alien worlds are made of rock just like the Earth, with water accounting for as much as five percent of their mass. Our planet, for example, only has 0.02%.
As for the size, density and amount of radiation the planets receive from their star, the fourth planet (TRAPPIST-1e) is the most similar to Earth; It seems to be the Earth-like in terms of its size and could house liquid water, as reported by the European Southern Observatory (ESO).
Furthermore, researchers also found that the seven planets are considered temperate, which means that under a certain set of geological and atmospheric conditions, all of the planets could meet the necessary requirements to allow water to remain in a liquid form on their surface.
Speaking about TRAPPIST-1, Dr. Amaury Triaud, from the University of Birmingham, a leading member of the international team, said:
“Of the seven planets, and of all the exoplanets that have been identified so far, Trappist-1e is the most resembling Earth, when we consider the amount of energy a planet receives from its star, and its density, which reflects its internal composition. As our next step, we would like to find out whether the planet has an atmosphere since our only method to detect the presence of biology beyond the solar system relies on studying the chemistry of an exoplanet's atmosphere.”
More information about the TRAPPIST-1 system, and whether or not it's an ideal place for alien life to thrive will become clearer once NASA’s new James Webb Space Telescope is launched into orbit next year.