Martian and terrestrial paleoclimatology: Relevance of solar variability

Evidence for past Martian rivers is perhaps the most puzzling and inconsistent present planetary problem, conflicting as it does with current conditions on the planet. This paper emphasizes the similar puzzling evidence that the Earth, as well as Mars, was warmer in the past. Neutrino evidence raises the suggestion that the sun was also “warmer” in the past. A hypothetical cause reconciling all effects is episodic change in solar luminosity on a time-scale of a few hundred million years. This paper outlines requirements and consequences of such a working hypothesis, with pro and con arguments. It is important to try to prove or disprove this hypothesis because it has radical implications for current science. For example, it suggests (1) climates of all the planets have been markedly altered simultaneously by solar changes, sometimes catastrophically; (2) solar changes have been a dominant “forcing function” driving biological speculation and evolution on Earth; (3) the concept of geologic uniformitarianism is somewhat modified by cosmic variables; (4) evolution of water-utilizing intelligent creatures near other stars may be less likely than has been thought, due to catastrophic planetary climate reactions to change in stellar luminosity.