For the first time, an exoplanet which orbits within the habitable zone of another star has been confirmed as being the size of Earth. These observations were made by both the W.M. Keck Observatory and the Gemini Observatory. Recent science articles on the discovery have been published, including that in the Science Daily news. Initially, the discovery was made with the Kepler Space Telescope at NASA, where a handful of smaller planets were found and verified with large ground-based telescopes. The discovery offers confirmation that there are Earth-sized planets within the habitable zone of other stars.The main reason that the discovery has been such a compelling one is that the planet resides in a temperate region where water could potentially exist in its liquid form, according to Elisa Quintana of the SETI Institute and NASA Ames Research Center. Quintana led the paper that was published in the science journal Science. The habitable zone of the planet is the region in which it orbits its star, due to the theory that life would most likely form on planets where there is liquid water. The existence of the planet was discovered initially by the Kepler Space telescope, identifying the existence of one of a handful of smaller planets before being verified by the large ground-based telescopes. The evidence obtained by the Kepler was based on the detection of planetary transits, somewhat like tiny eclipses of the host star by a planet when viewed from Earth. The report explains the difficulty in detecting and confirming these planets, and the hope that, with the new discovery, they will be able to search and find more.