Planetary Sciences
The study of the various objects within the solar system such as the planets, satellites, asteroids and other such objects which revolve round the sun is known as planetary science. Nicolaus Copernicus challenged the earlier belief that the earth was in the center and established that the earth along with the other bodies within the solar system revolve round the sun.
Space satellites such as Explorer 1 and the technologically advanced Hubble Space Telescope have contributed immensely to acquiring greater knowledge in this field. One of the main concerns of planetary sciences is the study of the processes which lead to the formation of the planets and the other objects in the solar system such as the natural satellites which orbit round the planets.
The planets are formed when gravitational attraction, accretion and collision acts upon the rotating disk of dense gas known as protoplanetary disk which envelopes a newly formed star. After the planet acquires a particular mass the various elements and matter within its composition settle down forming the different layers of its surface. This phase in the formation of the planet is referred to as planetary differentiation. It was during this stage that the Earth acquired its magnetic field after the core and the mantle were formed.
