After nine years of service, the Kepler space telescope orbits into retirement

It is definitely the end of an era in space exploration. The iconic Kepler space telescope, Nasa’splanet hunter is finally hanging up its boots. Launched in 2009, its mission was scheduled to last about four years. But the engineering marvel exceeded all expectations and has literally broadened our horizons. Its mission was to observe a patch of the sky and focus continuously on a large group of stars to find exoplanets

A reliable way to find exoplanets (planets from other star systems) is to observe a star and track any fluctuations in its brightness. Whenever a planet revolves around its star and crosses it, the light from the star dims ever so slightly. Since most planets follow a regular orbit around their star, the periodic intervals between dimming of the light from the star indicates a planet revolving around it. The Kepler telescope has observed over half a million stars and found thousands of exoplanets. While it was theoretically deduced by astronomers that other stars would likely had planets revolving around them, the Kepler telescope gave us definitive proof of the presence of exoplanets, thousands and thousands of them at that.

Some of the planets found were even earth-sized, rocky planets that were in the goldilocks zone, the optimum habitable distance for a planet from its star. The discoveries made by the Kepler telescope have dramatically increased our chances of finding habitable planets as well as alien life.

It is named after the astronomer Johannes Kepler, whose laws of planetary motion laid one of the foundations of Newton’s theory of universal gravitation.