Astronomy is the branch of science that deals with the study of objects comprising the universe. One might wonder when the universe is so huge; spreading millions of light years, how is it possible to study the objects in it? Astronomical studies are based on information gathered through various means.

Observational Astronomy

Mostly all the information gathered in the study of celestial objects are by studying the light patterns. As light travels through different media and strata, the property of light differs and these differences are studied to make conclusions. Based on the observed region of the electromagnetic spectrum observational astronomy can be further classified. While some of the regions of this spectrum are visible from earth, others are visible only from the outer space. The various classifications are briefly described here.

Radio Astronomy

The celestial bodies emit electromagnetic waves and these waves are studied to understand their structure and characteristics. The wavelength of radio waves is much higher than that of light. Probably Sun has been the most studied celestial object using radio astronomy. The solar flares and the sun spots emit strong radio waves which have been studied to reveal much information regarding this star. Compared to astronomical studies using light as the medium of study, radio astronomy provides greater advantage since radio waves do not get distorted traveling through the dust and gas in space.

Infrared Astronomy

In addition to emitting electromagnetic waves, the celestial bodies also emit heat which is used to study them. Infrared astronomy deals with the study of heat energy released by these bodies. Much of the universe is hidden from the visible range. This is mainly because of the thick gas and dust that engulfs the outer space. Infrared radiations can travel through the thick mace of gas and dust without getting scattered thereby not distorting the information. There are many “cool” objects in the universe. These include stars which are dying, planets of stars and moons of planets. Infrared aids in detecting such cool bodies of the universe.

Optical Astronomy

The most popular classification of astronomy is the optical astronomy. Many discoveries of the universe were through the naked eye and a keen observation of the skies. This is just the observation and study of visible light. This is also the oldest form of astronomy. Before the invention of telescope, astronomers observed the sky with naked eye from high altitudes. The information gathered was hand drawn before the advent of modern technology.

Ultraviolet Astronomy

Astronomical bodies also emit ultraviolet rays and the study of these rays in the electromagnetic spectrum is termed as ultraviolet astronomy. It is particularly useful in studying the density, temperature and chemical composition of astronomical bodies. It has also led to providing essential information regarding the evolution of galaxies.

X-Ray Astronomy

The Earth’s atmosphere is so thick that it blocks most of the X-ray radiations emitted from celestial bodies. To study the X-rays generated the observatories need to be located much above the earth’s surface. There are many sources of X-Ray radiation galaxies, supernovas, nebulae, pulsars, neutron stars, white dwarfs are just to name a few.

Gamma Ray Astronomy

The study of the shortest wavelength in the electromagnetic spectrum is known as Gamma Ray Astronomy. There are specialized telescopes to view gamma rays. Like X-Rays, most of the gamma rays are also absorbed by the earth’s atmosphere. Gamma Ray observation is mainly useful when the magnetic fields are very strong. These observatories are also located above the surface of the earth.

Optical astronomy has by all means been the favorite. It enables a backyard astronomer to make observations and come out with interesting conclusions. Naked eye has been the greatest contributor in discoveries related to the skies and probably will continue to remain so.