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>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 tha
by JonSkeptic 13y ago
>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.
- VLM 13y agoIf 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-barnards-star/ 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/ 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.
- Tuna-Fish 13y ago> astrological UGHH. Astronomical. The previous studies have mostly been lower bounds, not attempts to estimate the most likely count. We are still essentially terrible at locating earth-sized planets in earth-like orbits, we are much better at finding larger planets in closer orbits. Because of this, most of the planets that we do find are larger and/or closer, however, this obviously should not be used to deduce that most planets are larger and closer. This study is using honest statistical analysis to estimate the likelihood of earth-like planets from the data available.
- radley 13y agoPsychics at Cal Tech... http://www.youtube.com/watch?v=M3DoDMfDa_Q http://www.youtube.com/watch?v=M3DoDMfDa_Q
- danteembermage 13y agoI think a key point is that, unless planets rotate in a plane that nearly osculates our line of sight vector they will not be observed by current methods. Basically any planet whose orbit from our perspective looks like an oval rather than a left-right wobble will not be observed by current methods which check for light flickers as the planets cross their star. There are complex factors at work here, but I'd think a reasonable approximation would be that solar systems plane of rotation are oriented randomly. So, given random rotation, if we would expect to observe 1 out of 100 plants using this method and then find that there are planets around 1 out of 200, we can extrapolate that (1/100)/(1/200)= 1/2 of suns have planets. That explains the discrepancy anyway; since so many don't rotate in the right plane the fact that we observe them at the frequency we do, rare as it is, means they are in fact quite common. The universe just got a lot more exciting!
- maaku 13y agoOur current methods of observation are resolution limited and have huge, huge blind spots. When you correct for that, you get the "1 in 5" number.