Radio Physics and Radio Astronomy (Dec 2017)
THE SUN AND THE BIOSPHERE: THE PARADOXES OF 4 BILLION YEARS OF COEXISTENCE
Abstract
Purpose: The paper discusses the influence of the early Sun and the solar system parameters on the paleomagnetic field and the development of life on Earth. Design/methodology/approach: The available theoretical models of the early Sun and the geomagnetic field were verified by experimental paleomagnetic, geological and biological data. Findings: The first billion of years of coexistence of the Sun and biosphere is the time of paradoxes. One of the major being the so-called “faint young Sun paradox”. According to astrophysical models, the luminosity of the young Sun had to be by 30 % lower than it is today. This had formed the scarcity of energy coming to the Earth at which for the first 2.3 billion years the Earth surface temperature should be below the ocean water freezing point, i.e. the Earth was a frozen sphere. However, according to paleontologic data on fossilized ancient organisms, and also to geological data, the traceable ancient biosphere and ancient geostrata were formed at an average Earth surface temperature above 60°, and in the presence of a large quantity of liquid surface water. One more paradox is the essential mistiming in the occurrence of the Earth magnetic field according to theoretical models and experimental data. Theoretical models of the geodynamo state can evaluate the occurrence of a solid core about 1÷1.5 billion years ago, whereas by paleomagnetic data, the geomagnetic field (comparable in value to that recently measured), measured in zircons aged to 4.2 billion years can be determined. Сonclusions: Possible ways of resolving “the weak young Sun” paradox, the geomagnetic paradox and the isotope xenon paradox are systematizeed. The majority of them includes consideration of the terrestrial processes depending on the general situation in the early Solar system and accounting for the biosphere role in formation of the Earth surface physical conditions. The early Earth is considered as open dynamic system in the aggregate of solar-terrestrial relationship and the early Sun dynamics, dynamics of movement and formation of planets of the early Solar system (for example, migrations of early Jupiter), as well as within the limits of studying the Earth-Moon system.
Keywords
