Free Astronomy Magazine November-December 2018

41 ASTROBIOLOGY O n the side and below, two artworks by the illustrator Justinas Vitkus (Kaunas, Lithua- nia) that could describe the ap- pearance, on the ground and in space, of two habitable moons. AU) is very improbable. In that range of dis- tances, in fact, young moons have more chances to be removed from their orbits be- cause of the gravitational influence of the star, which in specific scenarios may exceed that of the planet, for example as a result of an inward planetary migration. In the light curves of the 284 selected plan- ets, Kipping and Teachey hoped to find es- sentially two different “fingerprints”, both of which could be associated with the rev- olution of possible moons around the plan- ets. A fingerprint is of a timing type and concerns the punctuality with which the planet begins the transit. By having Kepler (necessarily) observe mul- tiple transits for each planet, their revolu- tion periods around their stars are known, and it is, therefore, possible to foresee with great precision the beginning moments of