The TRAPPIST-1 system is a planetary system that is similar to the solar system but has seven planets that are all roughly Earth-sized, revolving around a rather old star, called the TRAPPIST-1. The planets under study are referred to by letters of the alphabet, planets b through h, in order of their distance from their ‘Star’, which is dubbed as ‘a’.
Scientists who were studying the TRAPPIST-1 system were keen to observe that the two exoplanets, the Planets ‘d’ and ‘e’ can prove to be ‘potentially habitable’. Both the said planets have moderate surface temperatures, modest amounts of tidal heating, and heat fluxes low enough to avoid entering a runaway greenhouse state, according to the scientists. There is also a strong possibility that the planet ‘d’ is covered with a global water ocean similar to Earth.
A Planetary Science Institute, US, scientist — Amy Barr said in a statement, “Because the TRAPPIST-1 star is very old and dim, the surfaces of the planets have relatively cool temperatures by planetary standards.” He continued that the planets have temperatures which range from 126 degrees Celsius that is colder than Venus, to as low as minus 106 degrees Celsius, which is colder than the Earth’s poles.
Since the star is old and weak, the planets also orbit very close to their central star, with orbital periods much lower as compared to our solar system, according to Barr. Also, the fact that their orbits are eccentric and not entirely circular, these planets encounter tidal heating just like the moons of Jupiter and Saturn, Barr added.
The scientists are assuming that the planets are composed of water ice, rock, and iron, which are the necessities to support life, they are yet to determine how much of each might be present, and how thick the different layers would be.
The TRAPPIST-1 star which appears as a faint red dwarf is floating in the space 39 light years away from us. It was discovered last year and since then onwards has become a matter of great interest in the scientific community. The reason behind its popularity is that it is the first time that so many “terrestrial” planets have been spotted around the same star, similar to a solar system. Amazingly, six out of seven planets of the system have the presence of water in some form.
Barr also learned that the masses and radii of the planets are not so well-constrained and that is the reason why they showed the full range of the possible interior structures and their compositions. The study also suggests that if the estimates of masses of the planets become more accurate and precise, then there is a higher chance of knowing whether the planets carry a significant amount of water or not.
The researchers used NASA’s Spitzer Space Telescope along with the European Southern Observatory’s Very Large Telescope, in the combination of other telescopes for their study. The distance seems to be the bottleneck of the study, according to the research co-author Vera Dobos, so the conclusions made are not very clear for understanding the complete insights of the ‘seven wonders of the other world.’