By Dr Fabienne Casoli, Dr Thérèse Encrenaz (auth.)
Exoplanet, extrasolar planet, exoEarth, exojupiter: neologisms nonetheless absent from many dictionaries. those phrases are, although, present between astronomers, and are heard of their solutions to a query already millennia previous: are there planets like ours somewhere else within the Universe? Greek atomists similar to Epicurus have been confident of the lifestyles of an enormous variety of sun structures like our personal, however it was once in simple terms in 1995 genuine solution started to emerge. An extrasolar planet have been detected... a planet orbiting one other star... a celebrity just like the sunlight. So, the sun approach used to be now not specific! through mid- 2006 greater than two hundred significant exoplanets were came upon. At this expense of discovery it sounds as if Earth-like planets should be came across inside of a decade. the invention of exoplanets held a few surprises, in that they exhibited very diverse features from what could have been anticipated. even if so much of them are gasoline giants of lots equivalent to Jupiter's mass, a result of relatively insensitive nature of present detection tools, why are they from ten to fifty occasions towards their stars than is Jupiter? How have been those 'hot Jupiters' shaped? one other shock approximately exoplanets is that a lot of them have very elliptical orbits, whereas the planets of the sunlight approach have even more round orbits.