STScI . The Faint Early Sun: Paradox, Problem, or Distraction? ... The Faint Early Sun: . ... That low luminosity is a problem when combined with what we know about the early atmosphere of the Earth because if the Earth?s surface were to become covered in ice then the albedo would be high enough to prevent the young planet from recovering. ... How much glaciation occurred at those early epochs? ... What limits can we set on the state at different times of the atmosphere and surface of early Mars? ...