The latest gimmick from this incredible telescope has to do with a small rocky planet called TRAPPIST-1 b. It is one of seven such balls of rock that orbit an ultracool red dwarf star (they call these things M dwarfs), located some 40 light years away from Earth in a constellation called Aquarius.
That’s a system we’ll probably learn more and more about in the near future, because according to scientists the place is “a great laboratory” if we want to study the “habitability around M stars.”
TRAPPIST-1 b is the innermost planet of the seven, and it’s a little over ten percent larger than our own Earth. It spins around its star at a distance about one hundred times smaller than the one between our planet and the Sun, and it’s tidally locked with its star, meaning one face of it is a burning hell and the other a freezing dark nightmare.
Being so close to the star means the side that always faces the light receives a lot of energy – about four times more than our planet gets from its Sun. And that also means the planet releases a lot of thermal emissions in the form of infrared light.
Seeing thermal emissions allowed people to estimate the temperature on the star-facing side of the planet, and according to them, that would be 450 degrees F (232 Celsius). Such a hot environment eliminates the chance of the place having a significant atmosphere and, by extension, being capable of supporting life as we know it.
True, TRAPPIST-1 b is not exactly in its system’s habitable zone, so that kind of was to be expected. What Webb proved though by being able to “measure such dim mid-infrared light” is that it can easily do the same for the other planets spinning around their M dwarfs, but others as well. And that ability should give us a proper sense of planets such as these having atmospheres capable of supporting life.