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The galaxy is full of Earth-like planets; King Tut’s strange demise; Reading a wagging tail; ‘Wasting’ disease hits starfish

The galaxy is full of Earth-like planets

Astronomers have calculated that there are 11 billion possibly inhabitable planets in our galaxy, providing compelling new grounds to believe we’re not alone in the universe. “With tens of billions of these water-laden Earth-size planets, surely some of them have all the necessary attributes of life,” University of California, Berkeley, astronomer Geoffrey Marcy tells The discovery “puts our beautiful home planet into a cosmic perspective and gives us knowledge about our place in our galactic community.” The research team used four years of data from NASA’s now-retired Kepler space telescope to compute how many planets lie in the “Goldilocks zone” of their solar systems, where surface temperatures are neither too hot nor too cold to support liquid water. They focused on a corner of the Milky Way containing 42,000 stars, watching for the signature dimming that occurs when a planet passes before a star to calculate what percentage of stars have planets. They then extrapolated that figure to the 200 billion stars that make up the Milky Way galaxy. The results: About one in five sun-like stars harbors a roughly Earth-size planet in the habitable zone, and the nearest is perhaps only 12 light-years away—close enough for a possible exchange of communication. Even if the conditions that produce life, let alone intelligent life, are very rare, the sheer number of planets would suggest we have plenty of company. The Milky Way is just one of billions of galaxies, so if you consider the entire universe, the possibility of intelligent life seems quite high.

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