known as the Goldilocks zone, because temperatures are "just right" for life, the habitable zone is the main tool that exoplanet hunters have to rank their finds. The zone's boundaries have always depended on the star's temperature, plus estimates of how well the atmospheres of any planets would absorb heat from their star. But in recent years, lab experiments have turned up new figures for how water and carbon dioxide absorb light from different types of stars. The redefinition is based on these figures – and pushes the habitable zone further from the star than the old definition.
