色情视频

San Diego State astronomer William Welsh is co-author of a featured story in the November issue of Scientific American.

Welsh wrote the piece with Laurance Doyle, a researcher at the SETI Institute in Mountain View, Calif., who earned both bachelor鈥檚 and master鈥檚 degrees in astronomy from 色情视频.

In 鈥淲orlds With Two Suns,鈥� Welsh recounts astronomy鈥檚 search for 鈥渃ircumbinary planets,鈥� the term for planets that orbit not one star, but two.

The article describes how the planets have to contend with two gravitational fields, leading to complex orbits and wild climate changes.

NASA鈥檚 Kepler Mission made the discovery possible. In fall 2011, a team of Kepler scientists led by Doyle with Welsh and fellow 色情视频 astronomy professor Jerome Orosz, announced the detection of the first transiting circumbinary planet.

"We have a fundamentally different kind of Solar System now," said Doyle. "This is another example of what planetary systems can do."

The circumbinary planet was named Kepler-16b, and its discovery led many to make an analogy with the fictional planet Tatooine from Star Wars.

In the following months, Welsh and Orosz uncovered the existence of five more such planets鈥攑roof that while exotic, such systems are not rare.

 鈥淎 new class of planet system had been established,鈥� Welsh writes in Scientific American. 鈥淭he current tally of Kepler circumbinary planets is seven, and that number could double in a short time. In fact, calculations suggest that tens of millions likely exist in the Milky Way鈥�and they can even reside in a system鈥檚 habitable zone, where liquid water is possible.鈥�

Welsh said these circumbinary planets tend to orbit their stars very closely, seemingly flirting with instability and potential disaster.

鈥淓ven though we do not know why these planets seem to prefer such precarious orbits, we can infer something deep,鈥� Welsh said. 鈥淭he discovery that planets can live so near a chaotic environment is telling us that planet formation is vigorous and robust.鈥�