What is ExtraSolar Planets ?
An exoplanet (extrasolar planet) is a planet located outside the Solar System. The first extrasolar planets to be discovered in 1991. The first confirmed detection of exoplanets was announced in 1992, with two planets found orbiting a pulsar.
Many of the extrasolar planets known are so-called hot Jupiters. This just means that they are Jupiter sized planets very close in to the central star. The reason that so many of these types of planets have been found is that the method used to discover extrasolar planets is most sensitive to heavy planets close in to the central star. Most extrasolar planets cannot yet be directly imaged because they are very small compared to their stars.