Ebook: The New Worlds: Extrasolar Planets

Exoplanet, extrasolar planet, exoEarth, exojupiter: neologisms still absent from many dictionaries. These terms are, however, current among astronomers, and are heard in their answers to a question already two millennia old: are there planets like ours elsewhere in the Universe? Greek atomists such as Epicurus were convinced of the existence of an infinite number of solar systems like our own, but it was only in 1995 that a real answer began to emerge. An extrasolar planet had been detected... a planet orbiting another star... a star like the Sun. So, the solar system was not unique! By mid- 2006 more than 200 giant exoplanets had been discovered. At this rate of discovery it seems that Earth-like planets may be found within a decade. The discovery of exoplanets held some surprises, in that they exhibited very different characteristics from what might have been expected. Although most of them are gas giants of masses comparable to Jupiter's mass, as a result of the rather insensitive nature of current detection methods, why are they from ten to fifty times closer to their stars than is Jupiter? How were these 'hot Jupiters' formed? Another surprise about exoplanets is that many of them have very elliptical orbits, while the planets of the solar system have much more circular orbits.

The detection and exploration of extrasolar planets is one of the most exciting and fast moving areas of astronomical research. The search for these new worlds has become the main objective for a new generation of giant ground-based telescopes as well as many future space missions.

Offering an engaging and complete story of the hunt for new worlds, this volume fully details the detection and exploration of extrasolar planets. Coverage begins by first looking at early searches for extrasolar planets, the very first discoveries, and the observational techniques involved. The book examines the very wide range of extrasolar planets that have been discovered during the past ten years and looks at what can be learned about such planets by studying the bodies in our own solar system. It also discusses the formation of planetary systems, the way in which such systems may evolve and the final systems of planets that result. In addition, the authors demonstrate how life might evolve on an extrasolar planet and look to the plans for future extrasolar planet searches. A number of Appendices summaries the extrasolar planet discoveries to date.