"Astronomy compels the soul to look upwards and leads us from this world to another."~ Plato
Today when we look around us, our technology and understanding of science have changed alot. From superstition to the logical science and from the "Earth is flat & center of the universe" to the "Earth is elliptical & revolves around the sun," this was all done because of the contribution of our ancestors such as Nicolaus Copernicus, Aryabhatta, Galileo Galilei, John Kepler, Albert Einstein, and many more. Their contribution to the physics, mathematics and space science took us to the next level. Now with accuracy we can travel to outer space, we can generate electricity, we can send messages within a fraction of seconds, and we can even solve any mathematical problem up to infinity.
Astronomy, Universe, Nebula, Black Holes, Rockets, etc. might be new to you, but this information will definitely change your perspective towards Astronomy. Let's make an attempt to understand Astronomy. Astronomy is the study of Planets, Moons, Stars, Galaxies, etc. which forms a Universe. Directly we can say that it is a study of the Universe. It applies Physics, Chemistry, and Mathematics to understand and to explain the origin of the Universe and its Astronomical objects and even their evolution.
Lets make our discussion more interesting by defining Universe. Universe is all space and time and its contents which includes Galaxies, Black Holes, Stars, Planets, etc. While the size of the Universe is still unknown, many Astronomers made attempts to understand the formation of the universe by giving interesting theories such as Big Bang Theory, and Steady State Theory.
Celestial Object is the basic term that is mostly used by astronomers for defining universe or for related theories. Celestial Object or Astronomical Object is a naturally occurring physical entity or structure that exists in the observable Universe. Examples of Astronomical Objects are Star Clusters, Nebulae, Galaxies. But my friends, do not get it confused with the Astronomical Bodies. Astronomical Bodies refers to a single, tightly bound contiguous entity that exist in the observable Universe. For example Stars, Planets, Moons, Asteroids, etc. are Astronomical Bodies. As we all know, exceptions are always there. Here "COMET" is identified as both Body and Object: It is a Body when referring to the frozen nucleus of ice and dust, and an Object when describing the entire comet with its diffusion coma and tail.
There is one more important term not to be forgotten: Spherical Astronomy or Positional Astronomy. It is the branch of Astronomy that is used to determine the location of objects on the Celestial Sphere. This is the oldest branch of Astronomy. Observation of the Celestial Objects have been, and continue to be, important for religious and astrological purpose, as well as time keeping. The science of actually measuring positions of celestial objects in the sky is known as Astrometry. The following are images that will definitely blow your mind: