‘Twilight zones’ on scorched planets could support life
Rocky extrasolar planets thought to be half frozen and half scorched might instead rock back and forth, creating large swaths of twilight with temperatures suitable for life.
Because of gravitational tugs with the objects they orbit, rocky bodies often settle into trajectories in which they always show the same face to their hosts. Such ‘tidally locked’ exoplanets would thus seem like bad candidates for life, since the hemisphere facing their host stars would roast and the dark side would freeze.
But a new computer model by Anthony Dobrovolskis of NASA Ames Research Center in California, US, suggests this is not always so. He finds that such planets can rock to and fro if they travel on elongated, or eccentric orbits, creating a ‘twilight zone’ that could be hospitable to life.
Source: newscientist.com
