ALIENS are surely AMONG US: Average star has TWO potentially Earth-like worlds (STA BREAKING NEWS and ARCHIVES)

by Theresa , Friday, February 06, 2015, 17:51

Boffins in Australia have applied a hundreds-of-years-old astronomical rule to data from the Kepler planet-hunting space telescope. They've come to the conclusion that the average star in our galaxy has not one but two Earth-size planets in its "goldilocks" zone where liquid water - and thus, life along Earthly lines - could exist.

“The ingredients for life are plentiful, and we now know that habitable environments are plentiful,” says Professor Charley Lineweaver, a down-under astrophysicist.

Lineweaver and PhD student Tim Bovaird worked this out by reviewing the data on exoplanets discovered by the famed Kepler planet-hunter space scope. Kepler naturally tends to find exoplanets which orbit close to their parent suns, as it detects them by the changes in light they make by passing in front of the star. As a result, most Kepler exoplanets are too hot for liquid water to be present on their surfaces, which makes them comparatively boring.

Good planets in the "goldilocks" zone which is neither too hot nor too cold are much harder to detect with Kepler, which is a shame as these are the planets which might be home to alien life - or alternatively, home one day to transplanted Earth life including human colonists, once we've cracked that pesky interstellar travel problem.

However there exists a thing called the Titius-Bode relation - aka Bode's Law - which can be used, once you know where some inner planets are, to predict where ones further out will be found.

Assuming Bode's Law works for other suns as it does here, and inputting the positions of known inner exoplanets found by Kepler, Lineweaver and Bovaird found that on average a star in our galaxy has two planets in its potentially-habitable zone.

That doesn't mean there are habitable or inhabited planets at every star, of course. Even here in our solar system, apparently lifeless (and not very habitable) Mars is in the habitable zone.

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