Exoplanets have been popping up in the world of astronomy with relatively high frequency over the last half decade or so, with the latest one being the 51 Pegasi b that was revealed back in October. Thanks to advances in technology and other factors, it is likely the first "Earth twin" planet will be discovered next year, according to scientists.
Thus far, exoplanets that have been discovered, while sharing characteristics with Earth, all possess factors that make them uninhabitable. 51 Pegasi b, for example, is close to its star, and as such, is extremely hot, rendering its landscape a scorched wasteland. Thus far, a legitimate Earth twin planet remains the subject of science fiction.
Multiple scientists and researchers believe that 2013 is the year when the first habitable planet similar in landscape and size to Earth will be found. The University of California, Berkeley's Geoff Marcy stated: "The first planet with a measured size, orbit and incident stellar flux that is suitable for life is likely to be announced in 2013."
The Earth twin will likely be discovered by High Accuracy Radial velocity Planet Searcher, more commonly called HARPS, the same technology that uncovered the exoplanet 51 Pegasi b. Says the University of Hertfordshire's Mikko Tuomi, "Estimating carefully, there are 200 billion stars that host at least 50 billion planets, if not more. Assuming that 1:10,000 are similar to the Earth would give us 5,000,000 such planets."