Steve Long Posted March 28, 2012 Report Share Posted March 28, 2012 Astronomy news these days just keeps getting more and more fascinating. http://www.bbc.co.uk/news/science-environment-17532470 Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted March 28, 2012 Report Share Posted March 28, 2012 Re: Tens Of Billions Of Earths [geek on] Here's the SPACE.com story on the same subject. Quote Link to comment Share on other sites More sharing options...
Cancer Posted March 28, 2012 Report Share Posted March 28, 2012 Re: Tens Of Billions Of Earths Astronomy news these days just keeps getting more and more fascinating. http://www.bbc.co.uk/news/science-environment-17532470 A note appeared in Nature back in January (the 12 Jan issue) from a different team, using fundamentally detection technique (surveys for gravitational lensing), coming to the same sort of conclusion: the most straightforward interpretations of the statistics they have is that (1) low-mass planets like Earth are more common than high-mass planets like Jupiter, and (2) in the Galaxy, there's about 1.6 planets per star with orbits between half an AU and 10 AUs. Quote Link to comment Share on other sites More sharing options...
Captain Obvious Posted March 28, 2012 Report Share Posted March 28, 2012 Re: Tens Of Billions Of Earths So when do we get to have one? I'd like to move there right away. Quote Link to comment Share on other sites More sharing options...
Cancer Posted March 28, 2012 Report Share Posted March 28, 2012 Re: Tens Of Billions Of Earths The telemarketers will still pursue you no matter how far you flee, you know. Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted March 28, 2012 Report Share Posted March 28, 2012 Re: Tens Of Billions Of Earths Thank Causality for light-speed lag! Quote Link to comment Share on other sites More sharing options...
Old Man Posted March 29, 2012 Report Share Posted March 29, 2012 Re: Tens Of Billions Of Earths Related: "Impossible" 13 Billion Year Old Planets Discovered What I find interesting about this article is that I hadn't realized metals and heavier elements were rare in the early universe, forming over in intervening aeons in stellar cores. This seems like it would have obvious ramifications for the Drake Equation. Quote Link to comment Share on other sites More sharing options...
megaplayboy Posted March 29, 2012 Report Share Posted March 29, 2012 Re: Tens Of Billions Of Earths So, the odds of us being completely alone in the universe are equivalent to what now, hitting Powerball and MegaMillions back to back? Quote Link to comment Share on other sites More sharing options...
Old Man Posted March 29, 2012 Report Share Posted March 29, 2012 Re: Tens Of Billions Of Earths I'm actually less worried about the existence of extraterrestrial life and more worried about how difficult it will be to go see it. Quote Link to comment Share on other sites More sharing options...
sinanju Posted March 29, 2012 Report Share Posted March 29, 2012 Re: Tens Of Billions Of Earths Related: "Impossible" 13 Billion Year Old Planets Discovered What I find interesting about this article is that I hadn't realized metals and heavier elements were rare in the early universe, forming over in intervening aeons in stellar cores. This seems like it would have obvious ramifications for the Drake Equation. Yeah, it seems obvious in retrospect when you realize that all the elements had to be formed in stars (and then handily scattered through the universe by supernovae or something), but it's weird to think about. Sometimes I think we're living in a time much the age of exploration, when the dark corners of the world map were being pushed back. "Here there be Dragons" was replaced by "And this is Indonesia, and this is Japan, and this is Bali...." When I was a wee lad, the universe outside of our solar system was a vast, unknowable emptiness. Now we're charting hundreds if not thousands of solar systems, and refining our techniques to be able to spot smaller and smaller (and more earthlike) worlds all the time. A lot of sci fi that postulated alien worlds anywhere nearby is going to be invalidated very shortly if it isn't already. I mean, we know it was probably not right anyhow--but now we'll be able to SEE that there's nothing and nobody else for X light-years. Also, the more I read about our history--specifically the history of the industrial revolution and the development of real science--the more I suspect that there could be a LOT of intelligent species out there who might remain at a primitive level indefinitely. As best we can tell, it took a particular confluence of physiology (hands, for one), geography, sociology, philosophy and pure dumb luck to create the right conditions for an Age of Reason. Otherwise, humans might have blundered along advancing only very, very slowly (if at all) with no concept of science, in cultures lacking in the characteristics that made innovation such an influence. Quote Link to comment Share on other sites More sharing options...
Christopher Posted March 29, 2012 Report Share Posted March 29, 2012 Re: Tens Of Billions Of Earths Related: "Impossible" 13 Billion Year Old Planets Discovered What I find interesting about this article is that I hadn't realized metals and heavier elements were rare in the early universe, forming over in intervening aeons in stellar cores. This seems like it would have obvious ramifications for the Drake Equation. Actually, that could mean our sun is a lot younger/lot older then calcualted. In large part they used the amount of heavier materials in the solar system/the sun as basis to calculate wich star generation our system belons too. Quote Link to comment Share on other sites More sharing options...
Cancer Posted March 29, 2012 Report Share Posted March 29, 2012 Re: Tens Of Billions Of Earths The influence of metallicity on lifetime of a star isn't strong until you get into extremely metal-poor stars. The 4.51 Gyr age for the Sun is bulletproof. As far as the influence on metallicity on planets: Most the Drake Equation sort of arguments are applied to the Galactic Disk, which is "only" about 10 Gyr old, and formed after the Halo. The oldest stars are (mostly) Halo stars, and the most metal-poor stars are strictly Halo objects. The Disk formed after substantial contributions of heavy elements were made by high-mass stars, and its metal content only goes down to [Fe/H] ~ -1 or -1.5 at the most metal-poor extreme. I'm still chasing down literature on HIP 11952. EDITS: Looks like [Fe/H] = -1.8 for this one (it is "better known as" HD16031). It's puzzling, because they don't mention HIP 13044 = CD -36 1052, which is a red horizontal branch star of possible extragalactic origin, that was announced a couple years back; that star has [Fe/H] = -2.1, and it's a post-main-sequence star to boot. Compared to that, this one in this press clip is nothing new, aside from being nearer to us. Quote Link to comment Share on other sites More sharing options...
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