The discovery of 7 Earth-Size planets by Nasa has been very popular. Let’s see some key aspects of this star and its planets.
Trappist-1: red dwarf with a mass equal to 8% of the solar mass. Just above the limit for nuclear fusion to be possible.
7 planets: Orbital period from 1.51 to maximum 20 days. Distance from star is about 3% Earth distance from Sun. Planet radius between 0.76 and 1.13 Earth’s radius.
As we can see the 7 planets are Earth-Size planets but besides that the system itself is very different from our own. This could mean it had a completely different evolutionary process.
Planets the size of Earth do not guarantee the necessary conditions for life to develop even if situated in the habitable zone of the solar system. A planetary magnetic field is required in order to have an atmosphere. Latest discoveries have proved how Mars lost its atmosphere because of the solar wind that slowly ripped away the molecules.
Even if the Trappist-1 is smaller then the Sun the planets are much closer then Earth. Star radiation could be a problem and other negative aspects due to this proximity could also be present.
Life needs challenges that force it to evolve, an unstable environment. Systems that are too stable don’t create the necessary conditions for life to evolve. Too unstable ones destroy the elementary life forms.
So why should someone do these researches? Models built to describe how the Solar System has formed need to be verified. Similar stellar system at different evolutionary stages could help understand what happened and what will happen to our system.
Trappist-1 is about 39.5 light year away. The simplest conversation would take about 80 years just for the initial presentations. Finding extraterrestrial life sure is interesting but it’s just the last of the goals.