This site may earn affiliate commissions from the links on this page. Terms of use.

Later well-nigh ten years and 2,681 planets, information technology's time to say good-goodbye to the Kepler space telescope. NASA has announced that the mission has ended. Dissimilar more open-ended missions similar Curiosity or Opportunity, Kepler always had a definitive shelf-life. In order to detect the minute variations around distant stars that serve as evidence those stars have planets, Kepler needed to be farther away from World than a telescope similar the Hubble. The infinite telescope relied on hydrazine fuel to go along its position in guild to comport scientific operations, and it'south much too far away from Earth to exist refueled or serviced. But it leaves behind a legacy of incredible accomplishments and a new telescope, TESS, is already continuing the good piece of work Kepler began.

Kepler drove a sustained doubling of our previous rate of planet discovery, with ii enormous surges in 2022 and 2022 that presumably reflect the analysis of data collected in previous missions (NASA says it will be busy analyzing previous data from Kepler for years to come). It wasn't that we had no thought if exoplanets existed before Kepler — nosotros'd detected them before. But what we didn't know very well at all was how mutual planets might exist. That might seem giddy, given that science fiction has presumed the being of alien worlds and races since long before Star Expedition was a gleam in Gene Roddenberry's centre. The science fiction greats like Asimov and Heinlein filled their galaxies with worlds beyond counting on the assumption that other planets must exist, but they didn't actually know if they did or not.

"When we started conceiving this mission 35 years ago we didn't know of a single planet outside our solar organization," said the Kepler mission's founding chief investigator, William Borucki, at present retired from NASA's Ames Research Center in California'southward Silicon Valley. "At present that we know planets are everywhere, Kepler has set up us on a new course that's full of promise for future generations to explore our milky way."

Borucki would know — he spent decades fighting for the mission that would become Kepler, at a time when a space-based telescope out of range from straight service missions was as much a flight of fancy equally warp drive. At the time Kepler launched, the modest group of planets that had been found were primarily hot Jupiters — gas giants orbiting very close to their parent stars. One of Kepler'south most important contributions to our understanding of the cosmos isn't merely that it found planets, but that it could detect planets in more scenarios than nosotros had previously been able to notice. The fact that it found and so many is one reason scientists are now more confident that planets are a common feature effectually stars, even if Kepler struggled to detect worlds that were strictly World-sized. Kepler relied on picking up minuscule variations in a star'due south luminosity as a planet passes in front of it. The larger the planet in relation to its host star, the larger the variation.

Kepler mostly plant planets much larger than our own, but it detected a solid number of nearly-Earth or Earth-like planets and set the stage for the Transiting Exoplanet Survey Satellite, or TESS. TESS is already in functioning and will survey an area of the sky 400x larger than what Kepler covered. Scientists expect that it could detect up to 20,000 exoplanets over its lifetime, potentially dwarfing Kepler's contribution.

Kepler-Habitable-Zone

NASA/Ames Research Eye/Wendy Stenzel

But as they say, you lot always call up your commencement — and it was Kepler that first showed u.s. that the number of planets scattered across the stars is, in fact, enormous. It was Kepler that gave the states our first glimpse of a handful of stars and worlds that might really harbor life. It was Kepler that found many planets orbiting in the habitable zone of their stars, and while this does not prove the existence of life, it proves that rocky planets can course at an appropriate distance from their host stars. Through ix tumultuous years on Earth, Kepler kept churning out new data, surviving reaction cycle failures, and pushing back the boundaries on our agreement of the heavens, clarifying whether the scientific facts we found confirmed or challenged our own ideas about how the universe works.

Well done, nosotros say. Well done, thou good and true-blue retainer. And a sincere thank-you to the NASA scientists who rescued the mission after its initial reactor wheel failure and who have tirelessly worked to analyze the information in all the years since. All of us who love space exploration without actually doing whatsoever of it owe a debt to those of you lot who do.

Or, for those who prefer the slightly cheekier version: So long, and thank you for all the planets.

Now Read: Kepler Spacecraft Wakes Upwards to Begin New Observations, Kepler Spots Potentially Habitable Super-Earth Orbiting Nearby Star, and NASA Puts Kepler Spacecraft to Sleep as Mission Winds Downward