The potentially life-supporting planet discovered by NASA’s Kepler Space Telescope last Tuesday may only be the first of many finds in NASA’s on-going search for habitable planets. The next steps in the search for distant life will be to look for Earth size planets orbiting at just the right distance from a star similar to our sun. Although they have not yet found a planet that fits all the criteria, NASA is on the lookout for an Earth-twin that could host human life.
For the time being Kepler -186f is the closest NASA has come to finding a planet enough like Earth to potentially sustain life. Life-sustaining planets are characterized by the presence of liquid water, and in order for a planet to contain liquid water, it must be orbiting its star at just the right distance to create a hospitable atmosphere, in what NASA’s Ames Research Center calls “the Goldilocks zone.”
While Kepler -186f happens to be orbiting at the right distance from its parent star, NASA has not yet been able to test the planet’s mass and composition. NASA research scientist Elisa Quintana explained that NASA searches for planets that mimic the characteristics of Earth and that “finding a habitable planet comparable to Earth’s size is a major step forward.” Despite the 500 light year distance between Earth and Kepler -186f, the discover is a great accomplishment for NASA and the first step towards finding a planet that is truly Earth-like.
Although NASA scientists have confirmed that the planet they discovered is potentially life supporting, it does not mean Kepler -186f is habitable. NASA research scientist Thomas Barclay suggested that Kepler -186f is more like Earth’s cousin, than its twin. It shares many properties that resemble those of Earth, but differs from Earth in many ways as well. So while KEPLER -186f is about the size of Earth, and it is orbiting within its star’s habitable zone, NASA researchers say there are likely dangerous amounts of radiation in its atmosphere.
Using the Kepler Space Telescope, NASA has discovered about two dozen planets so far that meet the Goldilocks criterion but this is the first one they have found to be Earth-sized. Small stars like Kepler -186f’s parent star live far longer than larger stars, providing more time for biological evolution to take place on orbiting planets. However, small stars tend to produce more solar flares and radiation, making planets within their habitable zones potentially hostile environments for human life.
The discovery of this potentially life-supporting planet may not change anything for the time being, but the journal Science has described it as “a landmark on the road to discovering habitable planets,” and NASA Astrophysics Division Director Paul Hertz says discoveries like these are essential to “continuing humankind’s quest to find truly Earth-like worlds.” The next steps in the search for distant life will be measuring the chemical composition of Earth-sized planets that are orbiting within the habitable zone of a sun-like star.
By Sandra Pugliese