Kepler

Kepler is a space observatory launched by NASA to discover Earth-like planets orbiting other stars.The spacecraft, named after the Renaissance astronomer Johannes Kepler,was launched on March 7, 2009.
Designed to survey a portion of our region of the Milky Way to discover dozens of Earth-size extrasolar planets in or near the habitable zone and estimate how many of the billions of stars in our galaxy have such planets, Kepler's sole instrument is a photometer that continually monitors the brightness of over 145,000 main sequence stars in a fixed field of view.This data is transmitted to Earth, then analyzed to detect periodic dimming caused by extrasolar planets that cross in front of their host star.This is the small area that Kepler look at for years

Kepler is part of NASA's Discovery Program of relatively low-cost, focused primary science missions. The Ames Research Center is responsible for the ground system development, mission operations since December 2009, and science data analysis. The initial planned lifetime was 3.5 years, but greater than expected noise in the data, from both the stars and the spacecraft, meant additional time was needed to fulfill all mission goals. Initially, in 2012, the mission was expected to last until 2016,but this would only be possible if all remaining reaction wheels used for pointing the spacecraft remained reliable. On May 11, 2013, a second of four reaction wheels failed, disabling the collection of science data and threatening the continuation of the mission.
As of July 2013, Kepler had found 134 confirmed exoplanets in 76 stellar systems, along with a further 3,277 unconfirmed planet candidates. In November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of sun-like stars and red dwarf stars within the Milky Way Galaxy. 11 billion of these estimated planets may be orbiting sun-like stars.The nearest such planet may be 12 light-years away!

On August 15, 2013, NASA announced that they have given up trying to fix the two failed reaction wheels. This means the current mission needs to be modified, but it does not necessarily mean the end of planet-hunting. NASA has asked the community to propose alternative mission plans "potentially including an exoplanet search, using the remaining two good reaction wheels and thrusters". On November 18, 2013, the K2 (also named "Second Light") plan proposal, which would involve using Kepler's remaining capability, photometric precision of about 300 parts per million, compared with about 20 parts per million earlier, to collect data for the study of "supernova explosions, star formation and solar-system bodies such as asteroids and comets, ... " and for finding and studying more exoplanets.In this proposed mission plan, Kepler would search a much larger area in the plane of earth's orbit around the sun.This would show how K2 would work using pressure from the solar wind to act like a reaction wheel

 The number of planet comfirm keep on adding up once people start looking over the data this is how they find a earth like planet orbiting around a Sun like star it goes around it star every 90 days and is within the goldylock zone(a area around a star that allow water to form on its surface,the area can be at different distance depending on the type of the star)
Confirm In addition to discovering hundreds of exoplanet candidates, the Kepler spacecraft has also reported twenty-six exoplanets in eleven systems that have not yet been added to the Extrasolar Planet Database. Exoplanets discovered using Kepler's data, but confirmed by outside researchers, include KOI-423b, KOI-428b, KOI-196b, KOI-135b, KOI-204b,KOI-254b, KOI-730, and Kepler-42 .The "KOI" acronym indicates that the star is a Kepler Object of Interest.

Both Corot and Kepler measured the reflected light from planets. However, these planets were already known, because they transit their star. Kepler's data allowed the first discovery of planets by this method, Kepler-70b and Kepler-70c. planet this is just a small list