In search of earth-like exoplanets: The legacy of the Kepler Telescope
Friday, August 23, 2013, 8:29 -
Scientists have been looking for and cataloguing exoplanets for the past 20 years. In that time, they have discovered more than 900 planets using a variety of techniques.
When the search for planets outside our solar system began, most of those discovered were gas giants, similar to Jupiter and Saturn, and likely unable to support life as we know it. But with the launch of the Kepler Telescope on March 7, 2009, the focus turned to searching for Earth-like planets orbiting other stars.
After just 4 years in space, Kepler may soon be retired. NASA recently announced its plan to possibly end the mission. The news came after scientists were no longer able to steer the device in different directions. However that doesn't mean the telescope is no longer useful. The agency is looking at ways to use what still works on the satellite to continue with the mission, albeit on a limited basis.
In its short career, Kepler has discovered an astonishing number of planets beyond our solar system. It has identified 135 exoplanets.
Of the earth-like planets it has discovered, Kepler 62e is one that closely resembles Earth. It weighs in at .082 on the Earth Similarity Index or ESI, with Earth as reference at 1.00. Kepler 62e was discovered in April of this year in the constellation Lyra. It is one of five planets orbiting a star that is 1,200 light years from Earth. Kepler 62e orbits its sun every 122 days, and is about 60 per cent larger than the Earth. Kepler 62f, another planet in the habitable zone of the same solar system, orbits the star every 245 days. It is about 40 per cent larger than Earth. The three other planets in the system have much closer orbits, and are considered too hot and inhospitable to support life.
With the Kepler Telescope in near retirement, you may be asking, what does the future hold? Well, NASA hope to launch the Transiting Exoplanet Survey Satellite, or TESS in 2017. Unlike Kepler, TESS will focus on relatively nearby stars. It will use an array of telescopes that will allow for a more complete view of the cosmos, with the purpose of discovering Earth-like planets in the habitable zones of their stars. NASA anticipates the mission will find still more exoplanets potentially capable of supporting life.