50 billion planets in our galaxy?

http://cosmiclog.msnbc.msn.com/_news/2011/02/19/6087627-planet-probe-spots-hot-prospects

50 billion planets in our galaxy?
Kepler detects extrasolar planets by staring at 150,000 stars in a single patch of sky, centered on the constellation Cygnus, and detecting the faint dips in light as planets pass over the stars’ disks.

Based on a statistical analysis of the data available so far, 44 percent of the 150,000 stars in the Kepler sample should have planets going around them, Borucki said. You could take that statistic and do some mathematical gymnastics to extend it to the entire Milky Way galaxy, which by conservative estimates has 100 billion stars. That would give you 44 billion stars in our galaxy with planetary systems — or the nice round number of 50 billion planets that was cited today by The Associated Press. That number has a high uncertainty factor, to be sure. But the bottom line is that there are almost certainly tens of billions of planets out there, including hundreds of millions of planets in habitable zones of outer space.

Borucki provided a more detailed breakdown:

• 10.5 percent of the stars in the sample are predicted to have Earth-size planets (that is, 50 percent to 125 percent as wide as Earth).
• 7.3 percent should have super-Earths (125 to 200 percent as wide as Earth).
• 20.8 percent should have Neptune-sized planets (two to six times as wide as Earth).
• 5.2 percent should have Jupiter-scale planets (more than six times as wide as Earth). All these numbers will get some additional tweaking, because they don’t reflect the breakdown for multiple-planet systems.

The preliminary estimates suggest that roughly one out of every 200 stars should have a planet in the habitable zone, where life could theoretically exist. If you extend that statistic to 100 billion stars in the Milky Way, you come up with a figure of at least 500 million planets in habitable zones.

There’s a lot of uncertainty about how many of those planets you could actually live on, because some of those worlds might be too big or otherwise unsuitable. For instance, on Kepler’s current list of 1,235 candidates, 54 potential planets are in habitable zones, but only five of them are around Earth’s size. KOI 326.01 appears to be the smallest of the five candidates. (“KOI,” by the way, stands for Kepler Object of Interest. SolStation.com has the full rundown on Kepler’s potentially habitable planet candidates.)

Earth-size planets and super-Earths would be considered the best prospects for alien life, but Borucki pointed out that even Jupiter-scale planets could have moons where life as we know it would do pretty well (as seen in the sci-fi movie “Avatar”).

“There’s a very rich ocean of planets out there to explore,” he said.

In an era where we have access to all of this knowledge, many still stubbornly believe that this was all done for humans.  Earth compared to the scale of the rest of the galaxy (let alone the universe) could only generously be characterized as an anthill.  What would we think of a world in which ants all thought that Earth was created by a magical entity outside the universe solely for them?  Is the idea not completely comical?  Yet this is the exact world that we live in.  And it gets worse: many of the different cliques of ants believe in different sorts of “magical entities” that created the Earth for them.  They have been legislating death for those who wish to be free of the belief in the “magical entity”, discriminating against one another, burning one another at the stake, cutting each others’ heads off and flying planes into each others’ buildings over the other group’s marginally different ideas of the same “magical entity”  throughout recorded history.  Again; it seems completely and totally ludicrous, but this is exactly the world that we are living in.  But the vast majority seem to truly unable to see the big picture.  Humans tend to simply accept the way things are and the way things have always been, even if it is wholly nonsensical, contrary to fact and despicable.  It is no wonder then, why many people continue to assert that religiosity and having faith are virtues, or that atheists cannot be good people, or to continue to assert a personal god despite massive amounts of evidence against humans being special in even the perspective of the universe, let alone a god’s eyes.  Their ancestors and family did it before them; apparently that’s powerful enough to overcome actual facts to the contrary.

“Questioning our own motives, and our own process, is critical to a skeptical and scientific outlook. We must realize that the default mode of human psychology is to grab onto comforting beliefs for purely emotional reasons, and then justify those beliefs to ourselves with post-hoc rationalizations. It takes effort to rise above this tendency, to step back from our beliefs and our emotional connection to conclusions and focus on the process. The process (i.e science, logic, and intellectual rigor) has to be more important than the belief.”

“Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own.”