Astronomers searching for worlds beyond the Earth celebrated a milestone on Tuesday as the number of observed exoplanets now numbers over 1,000. Although the first exoplanet was only discovered in 1992, recent advancements in technology have resulted in observations increasing exponentially and data from the now-defunct Kepler telescope could raise the number by thousands more. Despite this vast array of observed exoplanets, astronomers note that only a small fraction may actually be habitable. More on the story at BBC News.