Our galaxy is chock-full of rocky worlds, new research suggests!
Alright, just relax, ok?
First off, never get carried away by sensational headlines, especially when it comes to science and double-especially when it comes to any article suggestion, however subtle, that our galaxy is crammed shoulder-to-shoulder with space aliens and interstellar vacation spots.
A National Geographic News article says, that tens of billions of Earthlike worlds are strewn across the Milky Way, many of them circling stars very much like our own sun.
So what’s new? Well, what’s new is that recent studies have shown that in addition to Earthlike worlds circling sunlike stars, they have now been ‘seen’ circling larger stars. This increases the estimated number.
Or to put it in geek-speak…
“A fresh analysis of data from NASA’s Kepler mission, which launched in 2009, suggests this is not the case, according to new research presented at the annual meeting of the American Astronomical Society in Long Beach, California.
“We found that the occurrence of small planets around large stars was underestimated,” said astronomer Francois Fressin, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.
(Estimated fraction of stars having close orbiting planets of various sizes [1])
To find planets, Kepler stares at a patch of sky in the constellation Cygnus, made up of about 150,000 stars. The space telescope detects potential alien worlds by watching for telltale dips in starlight created when planets pass in front of, or “transit,” their parent stars.
Using their own independent software for analyzing Kepler’s potential planet detections, Fressin and his colleagues estimate that about 17 percent, or one in six, of all the sunlike stars in the Milky Way host a rocky planet that orbits closer than the distance at which Mercury orbits our own sun.
Since the Milky Way is home to about a hundred billion stars, that means there are at least 17 billion rocky worlds out there. (See Milky Way pictures.)
When the team expanded their search to Earth-size orbits or larger, they found that half of all sunlike stars may host rocky planets.
“Every time you look up on a starry night, [nearly] each star you’re looking at has a planetary system,” Fressin said.
OMG!!! Our galaxy is crammed shoulder-to-shoulder with space aliens and interstellar vacation spots!!!
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OK, let’s have some plain talking here….
How common are Earth-sized planets? Quite common, according to extrapolations from new data taken by NASA’s orbiting Kepler spacecraft. Current computer models are indicating that at least one in ten stars are orbited by an Earth-sized planet, making our Milky Way Galaxy the home to over ten billion Earths. Unfortunately, this estimate applies only to planets effectively inside the orbit of Mercury, making these hot-Earths poor vacation opportunities for humans. This histogram depicts the estimated fraction of stars that have close orbiting planets of various sizes. The number of Sun-like stars with Earth-like planets in Earth-like orbits is surely much less, but even so, Kepler has also just announced the discovery of four more of those.
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(When worlds collide. Literally!)
