Thousands of planets have been detected around other stars than our Sun during the last twenty years. A fraction of these so-called exoplanets are potentially habitable, i.e. they could - in theory - be rocky worlds harboring on their surfaces physical conditions suitable to the existence of liquid water, the primordial ingredient of life as we know it. Testing these planets' actual habitabilities - and maybe detecting extraterrestrial life along the way - requires detailed spectroscopic observations of their atmospheres that are out of reach with current technology ... except for three Earth-sized planets recently detected passing each orbit in front of a nearby host star of the smallest, reddest, and coolest kind. The seminar will describe how a Belgium-led project discovered the three planets, and how it should provide humanity with many more of these red worlds, each of them being an opportunity to detect life around another star within the next decade.