Probably a third of the most common planets in the Milky Way are ‘habitable’

about the episode

University of Florida astronomers believe – based on the latest data from two space telescopes – that a third of the most common planets in our Milky Way galaxy may harbor life.

Our Sun is unique in the Milky Way. The most common stars are much smaller—no more than half the mass of our Sun—and much cooler. The billions of planets in our universe orbit those smaller, cooler stars, called red dwarf stars.

Well, in order to host life, the planets must not be too far away from these stars. Then not enough heat is collected. But if it is too close, it can again suffer from strong tidal forces. The shape of the track plays a role in this. If it is not round but more elliptical, the planet deforms so much during this irregular orbit with varying gravity that it becomes very hot.

According to the researchers, a new analysis of data from the Kepler and Gaia space telescopes will now show that two-thirds of the planets in our Milky Way orbiting these dwarf stars are so close that they are roasting and life should not be possible. But a third of the planets would have to be in exactly the right orbit and distance from the star to support liquid water — and possibly life. So how many planets? Maybe hundreds of millions.

Read more about research here: A third of the most common planets in the galaxy could be in the habitable zone.