In 1950, which Russian astronomer revised the 'nebular hypothesis', proposing that the sun is surrounded by a solar nebula consisting mainly of hydrogen and helium as well as dust?

Explanation

The correct answer is Otto Schmidt. Key Points Nebular hypothesis:- Otto Schmidt was a Russian scientist who proposed the revised nebular hypothesis in 1950. The revised hypothesis proposed that the sun is surrounded by a solar nebula consisting mainly of hydrogen and helium, as well as dust. This hypothesis is widely accepted today and forms the basis of our understanding of the formation of our solar system.