Kepler, the telescope, reached more than twice its initial target, accomplishing original mission goals and seizing unexpected opportunities to answer questions about our galaxy and the universe, according to Charlie Sobeck, project system engineer at NASA's Ames Research Center. Over the course of nine years, Kepler discovered thousands of exoplanets (2,327 confirmed), but the end of its life is only the beginning.
In a statement, NASA said data collected from Kepler's deep space missions indicates our sky is filled with billions of hidden planets - more than the stars. "Now we know because of the Kepler Space Telescope and its science mission that planets are more common than stars in our galaxy".
Nasa's new space observatory, the Transiting Exoplanet Survey Satellite, or Tess, has already taken up the search for planets in the nearby cosmos, and giant telescopes both on the ground and in space are being created to detect and observe exoplanets - planets that circle stars outside our solar system. Kepler discovered more than 2,600 planets outside our solar system.
Before Kepler was launched, theories existed about the number and types of planets that might be orbiting other stars, but there was little hard data.
"Basically, Kepler opened the gate for mankind's exploration of the cosmos", William Borucki, Kepler's now-retired chief investigator, told reporters. The most recent analysis of Kepler's discoveries concludes that 20 to 50 percent of the stars visible in the night sky are likely to have small, possibly rocky, planets similar in size to Earth, and located within the habitable zone of their parent stars. Very sad, enjoy your retirement in the great void Mr. Kepler. The distinction helped scientists zero in on potential Earth-like planets and better the odds for finding life.
Engineers found out earlier this year that Kepler was nearly out of fuel.
Kepler showed us that "we live in a galaxy that's teeming with planets, and we're ready to take the next step to explore those planets", she said. Once the fix was made, NASA approved a new mission for the spacecraft, dubbed K2.
There is so much data that scientists are expecting to spend a decade in search of treasure in the trove that Kepler has provided. Kepler launched into an Earth-trailing heliocentric (sun-centered) orbit in 2009.
"To "Kepler" we do not know how often or rare in our galaxy there are planets", - says the head of the NASA astrophysics division, Paul Hertz.
And even though TESS will collect fresh data, Kepler's work still isn't done.
Kepler hands off the baton to TESS now, NASA said.
Two-third of the planets discovered so far are thanks to Kepler's observations.
The far more advanced James Webb Space Telescope, scheduled to lift off in 2021, should be able to reveal more about planets' mass, density and the makeup of their atmosphere - all clues to habitability.
In April, a spacecraft successor to Kepler ― NASA's Transiting Exoplanet Survey Satellite, or TESS ― was launched. "I'm excited about the diverse discoveries that are yet to come from our data and how future missions will build upon Kepler's results".