Detecting life outside of our solar system is no easy task, but scientists may have just pinpointed one of the best places to look: a star just 40 light-years away that contains three Earth-sized planets within its habitable zone, reports Phys.org.
The three planets have a radii of 1.11, 1.05, and 1.16 times that of Earth respectively, meaning this system is eerily similar to ours, comparable to Venus, Earth and Mars, which all lie within our habitable zone. The main difference is that the star in this system is an ultacool dwarf star, much cooler and smaller than ours. This isn't a concern, though, since all three of the exoplanets in the system orbit very close to their star, so temperatures on the planets are still quite comfortable.
Scientists discovered the planets using TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope), a 60-centimeter telescope operated by the University of Liège, based in Chile.
The star system is so close that scientists will be able to discern the planets' atmospheric compositions, which means that if they do contain life, signatures from the organisms might be detectable.
"These planets are so close, and their star so small, we can study their atmosphere and composition, and further down the road, which is within our generation, assess if they are actually inhabited," said Julien de Wit, co-author on the study. "All of these things are achievable, and within reach now. This is a jackpot for the field."
The fact that the star in the system is so small and cool is also a benefit to life because stars like this retain their luminosity for tens of billions of years, meaning it's a stable environment for life to develop in. It also helps researchers that the star is so dim, making the planets easier to spot.
Another neat aspect of this system is that all three planets are so close to one another that the others would be visible in the skies from each planet's surface. Imagine if all three of these worlds contain life; it would provide a fascinating experiment to see how life evolved on each world differently. It might even be possible that the planets could "seed" one another. Of course, this is mere speculative fantasy at this point, but it's fun to imagine.
"Now we have to investigate if they're habitable," said de Wit. "We will investigate what kind of atmosphere they have, and then will search for biomarkers and signs of life. We have facilities all over the globe and in space that are helping us, working from UV to radio, in all different wavelengths to tell us everything we want to know about this system. So many people will get to play with this [system]."