The Milky Way: Our Home in the Universe

Aakasha Ganga, Via Lactea or the Milky Way is our home in the Universe. The discovery of the telescope by Galileo Galilei had facilitated the sky watchers to notice a variety of geometrical forms in the sky. The use of photographic techniques have expanded our knowledge about galaxies. Galaxies can be grossly put into one of the 3 types: elliptical, spiral and irregular galaxies. Milky way is one among billions of galaxies present in the universe and it is spiral galaxy. Newtons law of gravitation explains the planetary motions in solar system. But to explain the motion of sun and other stars in galaxy one has to modify Newtonian gravity dynamics. Development of quantum mechanics, particle physics and the measurement of stellar velocities at unprecedented accuracies would help to unravel the mystery of the formation of Milky Way in near future.