While some scientists believe we may have reached the "tipping point" of no return when it comes to saving the earth from eradicating human life, NASA keeps hunting our solar system for planets that are hospitable to life. The job of hunting for "life hospitable planets" clearly is one that is like digging for a needle in a haystack -- only the haystack massively larger and the risks of not finding the planet in-time have much more dire consequences than almost any needle possibly could have.
Christmas presents have arrived early for these NASA planet-hunting scientists. Using the Kepler spacecraft they have confirmed a discovery of the first first alien world, named Kepler -22b - in a "habitable zone" of the universe. The planet is in "the perfect range of distances that would allow water to exist — and found more than 1,000 new exoplanet candidates, according to today's announcement. NASA says Kepler -22b as "their Christmas planet."
According to NASA, "Kepler-22b, [is] a planet known to comfortably circle in the "habitable zone" of a sun-like star. It is the first planet that NASA's Kepler mission has confirmed to orbit in a star's "habitable zone" -- the region around a star where liquid water, a requirement for life on Earth, could persist."
The discovery of Kepler 22b brings the Kepler space telescope's number of possible habitable planets to 2,326 - an event that has occurred in it's first 1,000 day since launch. Further confirmation is needed, however, this finding would almost quadruple the current total of "other-worlds" known to exist beyond our solar system. Kepler-22b's radius is approximately 2.4 times that of our own Earth. It has an orbital period of 289.9 days.
Discovery of a "potentially habitable other-world" is a must criteria, for Kepler. The stated outcome of Kepler is to identify potentially habitable earth sized planets. NASA scientists appear to be very excited about these new discoveries as they "are one small step for man" --- no, they didn't say that -- though it means we are making significant progress towards discovering a second world that is amenable to human life.
Confirmation from NASA means that they seen the planet cross in front of its sun 3 times. It does not mean that scientists know whether life actually exists there. They are using a set of criteria that indicated that the planet has conditions are right for life. Such planets have the right distance from their star to support water, plus a suitable temperature and atmosphere to support life.
NASA scientists are honing on it was qualifies as a "habitable" planet by attempting to identify those planets that also have atmospheres - because for water to exist you have to have an atmosphere. Based on this new and more discerning criteria for habitability NASA now has identified 48 planets in the habitable zone. Surface gravity is another criteria that NASA has begun to introduce into their critera.
Any planet that has an atmosphere is going to have a greenhouse effect - and warm the planet. Scientists believe that if the greenhouse effect on Kepler 22b functions in a similar manner to earth -- then the the surface temperature should be a beautiful 72 degrees Fahrenheit (22 degrees Celsius) -- this does not factor the impact of rain, snow or wind. NASA reports that it is possible that Kepler-22B has clouds in its atmosphere.
Kepler scientists are an optimistic bunch though. They estimate that at least 80 % of the discoveries made by Kepler will likely be the "real deal." "This is a major milestone on the road to finding Earth's twin," according to Douglas Hudgins, Kepler program scientist at NASA.
"The tremendous growth in the number of Earth-size candidates tells us that we're honing in on the planets Kepler was designed to detect: those that are not only Earth-size, but also are potentially habitable," said Natalie Batalha, Kepler deputy science team lead at San Jose State University in California.
You may be wondering if we can even get there and if not what's the point of this since it has cost NASA around $700 million to-date. Kepler-22b is six hundred light years or approximately 3.5 quadrillion miles. Yikes! Yet, how will we ever get there? According to NASA the discovery is important as it contributes to knowledge of whether or not there is life elsewhere and in what circumstances it develops, and how common it is. Their goal is to find planet number 2 so that they can rule out that earth is the only hospitable environment of it's kind for human life to exist. Simply stated, think of the change in the social impact and the direction that would occur when we discover that life exists someplace else.
The accompanying video is a detailed report from NASA about their "Christmas planet."