Tens of billions of potentially habitable, Earth-size planets in our galaxy
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Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy
#2>One in five stars in our galaxy like the Sun have planets about the size of Earth and a surface temperature conducive to life
That is a considerable claim that jars with most of the astronomical data I've seen. 1 in 5 is far more probable, perhaps an order of magnitude more probable than I've previously heard.
Does anyone have studies that corroborate their claim?
[EDIT] Later in the article data is cited that more closely matches what I've heard.
>Independently, Petigura, Howard and Marcy focused on the 42,000 stars that are like the sun or slightly cooler and smaller, and found 603 candidate planets orbiting them. Only 10 of these were Earth-size, that is, one to two times the diameter of Earth and orbiting their star at a distance where they are heated to lukewarm temperatures suitable for life.
It makes for a much less sensationalist title, but it seems to have more research behind it.
Over all, I would question the method that caused them to arrive at the 22% idea. I'm not sure that they are accounting for the missed planets correctly; if they are, I would like to see their estimates corroborated.
[EDIT 2] Thank you, Tuna-Fish. Typo corrected.
Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy
#3I look forward to the discussion revolving around the concept of ten billion inhabited worlds colliding with the prevailing HN wisdom that the only place to do tech in the known universe is SV.
That's nice that you want to do tech, but if you stay on flyover Tatooine you'll never work on anything more modern than a moisture vaporator, better boot up the x-wing and fly to SV back on old Earth if you want to get paid to do stuff with jquery.
Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy
#4I've seen this reported as 2 (http://www.theguardian.com/science/2013/nov/04/planets-galax...) and 8.8 (http://abcnews.go.com/Technology/wireStory/study-88-billion-...) billion this week. Anyone know why the wildly different numbers being reported for the same research?
I'm also curious about Earth-sized moons around gas giants in the habitable zone.
Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy
#5>One in five stars in our galaxy like the Sun have planets about the size of Earth and a surface temperature conducive to life That is a considerable claim that jars with most of the astronomical data I've seen. 1 in 5 is far more probable, perhaps an order of magnitude more probable than I've previously heard. Does anyone have studies that corroborate their claim? [EDIT] Later in the article data is cited that more…
If you're looking for the astrobites treatment, I think this is Howard and Marcy's paper, or at least Howard and Marcy are authors on this exoplanet paper discussing this topic:
http://astrobites.org/2012/09/02/looking-for-planets-around-...
Although I think the reported 22% number comes from a different exoplanet paper on the topic of moon formation, probably on the assumption you need tidal forces for ... something:
http://astrobites.org/2011/06/16/searching-for-pandora/
I highly recommend the astrobites RSS feed. Formerly in my google reader, now in my newsblur.
Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy
#6But let's say what we really hope for is true.
What if we somehow discover that a large number of these planets are teaming with life ?
What then ?
How would that help us ? Spiritually, economically ? Wouldn't that make us feel even less significant ?
I'm just wondering, why are we hoping there is life out there and what would we do if we find it ?
Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy
#7I've seen this reported as 2 ( http://www.theguardian.com/science/2013/nov/04/planets-galax... ) and 8.8 ( http://abcnews.go.com/Technology/wireStory/study-88-billion-... ) billion this week. Anyone know why the wildly different numbers being reported for the same research? I'm also curious about Earth-sized moons around gas giants in the habitable zone.
The research says 22% of sun-like stars have Earth-like planets in their habitable zone. Seems like they're all based on different assumptions of the number of sun-like stars.
>Guardian: There are around 100bn stars in our galaxy, of which 10% are like the sun.
>ABC: There are about 200 billion stars in our galaxy, with 40 billion of them like our sun, Marcy said. One of his co-authors put the number of sun-like stars closer to 50 billion, meaning there would be at least 11 billion planets like ours.
>Kurzweil: The estimate was based on a statistical analysis of all the Kepler observations of NASA’s Kepler space telescope of the 200 billion stars in our galaxy. Given that about 20 percent of stars are Sun-like, the researchers say, that amounts to several tens of billions of potentially habitable, Earth-size planets in the Milky Way Galaxy.
n.b. Kurzweil's math clearly sums up to 8.8. Maybe he's adding in stars unlike the Sun and not mentioning it (given that the article discussed is based on earlier work showing 15% of red dwarfs have Earth-like planets in the habitable zone: http://www.nytimes.com/2013/11/05/science/cosmic-census-find... ).
Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy
#8But let's say what we really hope for is true. What if we somehow discover that a large number of these planets are teaming with life ? What then ? How would that help us ? Spiritually, economically ? Wouldn't that make us feel even less significant ? I'm just wondering, why are we hoping there is life out there and what would we do if we find it ?
I think it's more dangerous to seek alien life, spiritually and economically then it is to actually discover it.
Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy
#9This news reminded me of Carl Sagan's Cosmos episode about the Drake Equation (http://en.wikipedia.org/wiki/Drake_equation) that I watched as a kid. It is really an improved estimate for a couple of the terms.
That segment of Cosmos is online: http://www.youtube.com/watch?v=MlikCebQSlY
Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy
#10But let's say what we really hope for is true. What if we somehow discover that a large number of these planets are teaming with life ? What then ? How would that help us ? Spiritually, economically ? Wouldn't that make us feel even less significant ? I'm just wondering, why are we hoping there is life out there and what would we do if we find it ?
Hopefully, we'd get a little attitude adjustment, question religion more and work together as a human race in the newfound awareness of our place in the universe. Perhaps also work towards actually surviving as a race for a while instead of selfishly exploiting every resource before others do.