When our Sun runs out of nuclear fuel, it will shed its outer layers, while what’s left of the core will remain as a white dwarf: an object the size of Earth, but far more massive. During the final stages of the Sun’s life, Earth is likely to perish as a habitable world, but that’s not necessarily the case for every planet orbiting a Sunlike star. That’s the basis of a new paper, which posited that white dwarfs may even provide the best hope for detecting extraterrestrial life.

The advantages of these systems would be manifold: a white dwarf is much smaller than a star, so if a planet passes between it and us, far more light is blocked. And Avi Loeb and Dan Maoz proposed that at least some signs of life might have survived the deaths of these stars. The light emitted by the white dwarf could highlight any oxygen in the exoplanet’s atmosphere, which would be seen as a strong hint of life. [Read more…]

Living planets in a stellar graveyard