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There’s been a lot of buzz lately about planets in habitable zones, particularly with the recent discovery of an Earth-sized planet orbiting a star in a zone where liquid water could exist.

But Geoff Marcy, an exoplanet researcher at the University of California at Berkeley, urges the astronomy community to adopt caution over the term “habitable zone.” Earth is still the only place in the Universe that we know has life. His team recently wrote about this in a survey paper looking at worlds close to Earth’s size around Sun-like stars.

The paper, “Occurrence and core-envelope structure of 1–4x Earth-size planets around Sun-like stars,” is available in preprint version on Arxiv and has been accepted for publication in the Proceedings of the National Academy of Science.

“The key result is that planets that are between the size of the Earth and let’s say, twice the size of the Earth are extraordinarily common,” said Marcy, whose team has discovered more than 250 planets around other stars.

“Something like 26 percent of all of Sun-like stars have a planet between the size of the Earth and twice the size of the Earth orbiting at a distance from the star that’s within about half the Earth-Sun distance.”

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There’s been a lot of buzz lately about planets in habitable zones, particularly with the recent discovery of an Earth-sized planet orbiting a star in a zone where liquid water could exist.

But Geoff Marcy, an exoplanet researcher at the University of California at Berkeley, urges the astronomy community to adopt caution over the term “habitable zone.” Earth is still the only place in the Universe that we know has life. His team recently wrote about this in a survey paper looking at worlds close to Earth’s size around Sun-like stars.

The paper, “Occurrence and core-envelope structure of 1–4x Earth-size planets around Sun-like stars,” is available in preprint version on Arxiv and has been accepted for publication in the Proceedings of the National Academy of Science.

“The key result is that planets that are between the size of the Earth and let’s say, twice the size of the Earth are extraordinarily common,” said Marcy, whose team has discovered more than 250 planets around other stars.
“Something like 26 percent of all of Sun-like stars have a planet between the size of the Earth and twice the size of the Earth orbiting at a distance from the star that’s within about half the Earth-Sun distance.”

 
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