Though not literally ten identical versions of Earthy, NASA has recently announced that among the 219 planets they’ve just added to the list of planets beyond the Milky Way, 10 of them are Earth-like. What this means is that they are positioned at the perfect distance from their respective stars/suns to support water and, more specifically, for water to pool on their surfaces.
The 200 plus planets were discovered by NASA’s Kepler Space Telescope which had been observing some 200,000 stars making up the Cygnus constellation. The news that ten of the planets around some of those stars could support water is exciting because scientists believe that liquid water is a primary factor in a planet being able to sustain life.
Kepler was launched in 2009 with the primary purpose of seeking out planets similar to Earth in its capacity to support life. Its first four-year deployment discovered 2,335 valid planets and 1,699 potential ones with approximately 50 of those appearing similar in size and temperature to Earth. Scientists believe there are approximately 3,500 planets beyond the Milky Way.
Kepler has also provided a means for determining the surface structure of a planet, as in whether or not it is solid or gaseous; Earth has a solid surface and Neptune, for example, has a gaseous one. Solid planets would be more likely to hold and support life.
One scientist noted that the data seems to show that a planet like Earth—solid, with a similar climate and the ability to support liquid water, are more of an exception than the norm.