In February of 2017, a team of European astronomers announced the discovery of a seven-planet system orbiting the nearby star TRAPPIST-1. Aside from the fact that all seven planets were rocky, there was the added bonus of three of them orbiting within TRAPPIST-1’s habitable zone. Since that time, multiple studies have been conducted to determine whether or not any of these planets could be habitable.
In accordance with this goal, these studies have focused on whether or not these planets have atmospheres, their compositions and their interiors. One of the latest studies was conducted by two researchers from Columbia University’s Cool Worlds Laboratory, who determined that one of the TRAPPIST-1 planets (TRAPPIST-1e) has a large iron core – a finding which could have implications for this planet’s habitability.