Hmm, "Our Milky Way galaxy contains a minimum of 100 billion planets according to a detailed statistical study based on the detection of three extrasolar planets by an observational technique called microlensing."<p>So we looked in 3 places, found 3 planets and are extrapolating to 100 billion? Surely I would wait for a few more examples?<p>Edit: Reading the full story, "Of the approximately 40 microlensing events closely monitored, three showed evidence for exoplanets. Using a statistical analysis, the team found that one in six stars hosts a Jupiter-mass planet. What's more, half of the stars have Neptune-mass planets, and two-thirds of the stars have Earth-mass planets. Therefore, low-mass planets are more abundant than their massive counterparts."<p>I dont get it. Any explanation?
Sounds a little more lonely when you read "it's likely there are a minimum of 1,500 planets within just 50 light-years of Earth." 1,500 isn't that many, and 50 light-years is a really long distance.
This is very exciting.<p>On a related note, the number put forth by the study (at least one planet per star, on average) is roughly consistent with Drake's 1961 estimate that half of all stars will have planets, and stars with planets will have 2 planets capable of developing life.<p>Except, of course, that Drake estimated an average of >=1 <i>habitable</i> planets per star. Still, it's good to see one of his estimates being corroborated.<p><a href="http://en.wikipedia.org/wiki/Drake_equation" rel="nofollow">http://en.wikipedia.org/wiki/Drake_equation</a>
I believe there are much more planets because not every planet has a star: <a href="http://www.dailygalaxy.com/my_weblog/2011/09/billions-of-dark-planets-roam-the-milky-way.html" rel="nofollow">http://www.dailygalaxy.com/my_weblog/2011/09/billions-of-dar...</a>
I cannot even start to grasp the meaning of 100B planets.<p>I read that if the "Milky Way" was the size of China, then the the sun and 6 closest planets around together would be the size of one quarter.