ABSTRACT
Throughout recorded history and perhaps even before, we have wondered about the probable existence of other worlds, similar or dissimilar to our own. The earliest understanding of the solar system indicates that there were indeed other worlds in orbit about our Sun. Our growing understanding of their nature reveals that all are dramatically different from our Earth and also very different from one another. As we gathered knowledge that the stars in the sky are other Suns that are part of distant galaxies, consisting of billions of stars; it appears as a near certainty that other planets must orbit those other stars [1]. Until the early 1990s, this could not be proven, but, through the efforts through research, radio and optical astronomers detected small changes in stellar emission to show the presence of planetary systems around other stars. These planets are named as exoplanets [2] for the purpose of distinguishing them from our own solar system neighbors. Extrasolar planets, or popularly called exoplanets, are planets orbiting stars outside our solar system. The first discovery of the exoplanet was confirmed in 2003 [2]. It is very difficult to detect these planets directly, as they are very dim and hard to see due to the brightness of the stars they orbit. As an example, we may mention that the Sun is a billion (109) times brighter than Jupiter and 10 billion (1010) times brighter than our Earth.
