New data from the Kepler telescope suggests that the number of exoplanets the same size of Earth number in the billions. The Kepler telescope, which, over the past year, has been instrumental in discovering exoplanets that could potentially harbor life, has been tracking a fixed part of sky since 2009 and in its findings has discovered that around one in six stars observed so far host an Earth-like planet in close orbit, putting the total number of such a haul at around 17 billion.
The data, gathered by NASA’s Kepler Space Observatory has been put together since Kepler’s launch nearly four years ago, and the telescope has routinely given details of the nearly 150,000 stars it has observed so far, giving, along with the trove above, 461 new planet candidates, putting the total number of planets that the telescope has discovered at 2,740.
The results, presented at 221st meeting of the American Astronomical Society in California, suggested that of the stars observed, 17 percent of them host a planet that is roughly 1.25 times the size of the Earth, with an orbit of some 85 days, putting these planets in the category of Mercury. By this percentage then, there are potentially some 17 billion Earth-like planets out there in space.
Of course, Kepler’s results go even a step further, as while finding an Earth-sized planet is one thing, finding these planets in the “Goldilocks Zone” from their stars is another. This “golden mean” so to speak of the habitable zone represents the ideal distance that a planet should be from its star to be of the right temperature and thus possess liquid water, something which is so far uniquely patented to planet Earth. But in Kepler’s discoveries, out of the 2,740 planets discovered, only 10 are said to reside in the habitable zone.
Speaking about the results, Dr. Christopher Burke of the Seti Institute said, "What is particularly interesting is four new planets - less than twice the size of Earth - that are potentially in the habitable zone, the location around a star where it could potentially have liquid water to sustain life. It's very exciting because we're really starting to pick up the sensitivity to these things in the habitable zone - we're just really getting to the frontier of potentially life-bearing planets.”