Short notes on Gaseous tidal hypotheses



These postulate a hot ball of fire origin of the Earth and other planets. Planets and satellites were formed by gradual cooling and solidification of originally hot and gaseous fragments which were detached from the sun and/or another star under mutual gravitational attractions.

According to Buffon (1749), the planets evolved from hot gaseous bodies which were detached from the sun as a result of its collision with another star of our galaxy.

Jean (1919) and Jeffrey (1925) postulated tidal hypotheses which are otherwise known as "Hit and Run" hypotheses. A big star during its course of wandering in the space approached the sun and caused violent tidal distortion in the sun by its very strong gravitational pull.

As it came very close to the sun, parts of the sun affected by strong tide were pulled away in the from of a spindle shaped fdament which was in unstable state. Then, as the big star receded away, this unstable filament broke away into pieces of hot and gaseous masses. Few of them were carried away along with the receding star; while major bulk of them fell into the gravitational field of the Sun. They formed globular masses orbiting the sun. The bigger masses gradually cooled down and concentrated to planets. The smaller masses solidified into the satellites. One of the planets further broke away into places called asteroids / planetoids.

The plus points of this hypothesis are (i) it explains the ordering of the planets sizes (cigar shaped) shown in and arrangement of satellites. Failure of this concept is its lack of facts to explain the difference in elemental composition between the parent suns which contain light. He and elements and the planets which are composed of heavier elements of Si, Al, Fe and Mg.