tkdguy Posted December 10, 2014 Author Report Share Posted December 10, 2014 "Don't break the Hubble!" Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 10, 2014 Author Report Share Posted December 10, 2014 Orbital Sciences buys Atlas 5 booster Did a gamma ray burst cause a mass extinction? Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted December 10, 2014 Report Share Posted December 10, 2014 The GRB article was good -- anything that explains the Fermi Paradox I like! tkdguy 1 Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 16, 2014 Author Report Share Posted December 16, 2014 Voyager 1 Experiences Three Tsunami Waves In Interstellar Space Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted December 16, 2014 Report Share Posted December 16, 2014 Space Storms!! Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 17, 2014 Author Report Share Posted December 17, 2014 Organic chemistry on Mars Cancer 1 Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted December 18, 2014 Report Share Posted December 18, 2014 The Indian manned space program putters along nicely, with the Crew Module Atmospheric Re-entry Experiment carried out earlier today, as a waypoint for the development of the ISRO Orbital Vehicle. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 19, 2014 Author Report Share Posted December 19, 2014 Kepler discovers super Earth 180 light years away Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 23, 2014 Author Report Share Posted December 23, 2014 Mars took longer to dry out than we thought. Could Ceres hold life? Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 26, 2014 Author Report Share Posted December 26, 2014 Why is Rosetta's Comet shaped like a duck? Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 29, 2014 Author Report Share Posted December 29, 2014 Geysers on Europa? Where? Asteroids: Breaking up is hard to do. Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted December 29, 2014 Report Share Posted December 29, 2014 Geysers on Europa? Where? Huh. Perhaps it was an impact that got imaged? Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 30, 2014 Author Report Share Posted December 30, 2014 Who knows? I hadn't heard about it until now. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 30, 2014 Author Report Share Posted December 30, 2014 New Year's Comet? Incoming! Quote Link to comment Share on other sites More sharing options...
NuSoardGraphite Posted December 30, 2014 Report Share Posted December 30, 2014 Re: More space news! Not buying this. More later. That's because the moon is a derelict space ship. according to contactee Alex Collier, most ET species in our galaxy use hollowed out planetoids as starships. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 31, 2014 Author Report Share Posted December 31, 2014 Mystery object near black hole L. Marcus 1 Quote Link to comment Share on other sites More sharing options...
DShomshak Posted January 1, 2015 Report Share Posted January 1, 2015 The latest Scientific American has an article about the potential for "superhabitable" planets -- worlds that are actually better than Earth at sustaining Life As We Know It. (Sorry, no link. I read SA in Dead Tree, and me big tech dummy who doesn't know how to post links on this forum. Maybe someone else could do this? Sorry again.) Dean Shomshak L. Marcus and pinecone 2 Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted January 1, 2015 Report Share Posted January 1, 2015 I checked http://www.scientificamerican.com/ -- no such article available, but it's indeed listed as one of the features of the latest Dead Tree issue. Quote Link to comment Share on other sites More sharing options...
Zeropoint Posted January 2, 2015 Report Share Posted January 2, 2015 The idea sounds a little strange to me--Life As We Know It is life evolved for Earth specifically--how could any other planet be better for Earth life than Earth? It makes me want to read the article to see what they're actually saying. Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted January 2, 2015 Report Share Posted January 2, 2015 Dean is an agent of Scientific American! He wants to boost their sales!! Quote Link to comment Share on other sites More sharing options...
DShomshak Posted January 2, 2015 Report Share Posted January 2, 2015 In brief: Author Rene' Heller notes that Earth's habitability -- measured by actual quantity of life -- has varied widely over time. During the Carboniferous, Earth's biomass was probably larger than it is now, what with our large desert areas, the near-lifeless middle of the oceans, etc. More importantly, habitability should be summed over time. Earth's period as a life-bearing planet is almost over, geologically speaking: As the Sun gets brighter and hotter with age, the "Goldilocks Zone" moves outward. Current estimates place Earth at its inner edge. Within the next billion years or so, the oceans evaporate. Earth also faces some geological exhaustion-points. The magnetic field that protects the atmosphere, and the plate tectonics that keeps carbon cycling between atmosphere and lithosphere, are driven by a combination of relic heat from the Earth's formation and heat from radioacive decay. The supply of radioactive elements inexorably declines. In a billion years or so, internal heat drops to the point that both processes stop. CO2 builds up in the atmosphere, unless the atmosphere gets blown away by the solar wind. Bad either way. Heller suggests that a larger planet would sustain its geological processes longer, through its larger supply of radioactives and greater heat of formation; while a K dwarf star would heat more slowly, leaving the planet within its Goldilocks Zone many billions of years longer. He estimates that a planet twice Earth's mass, orbiting a K dwarf star, could remain habitable for many billions of years longer than Earth. <oreover, the higher gravity could mean a flatter topography, with fewer high, expansive continents to develop deserts and more life-rich archipelagos. I see potential problems with Heller's arguments (notably, an article I read several years ago that a planet significantly larger than Earth can't have a liquid core -- the greater pressure keeps it solid, even if it's hotter). But it's an interesting alternate view of habitability, and a healthy counterpoint to the "Rare Earth" school that says even the slightest difference from Earth would make complex life impossible. I think one should hesitate to be too certain, in any direction, until we have more than one example of a life-bearing planet to study -- and as a gamer, I prefer to err on the side of possibility! Dean Shomshak mikeward2534 and L. Marcus 2 Quote Link to comment Share on other sites More sharing options...
Zeropoint Posted January 2, 2015 Report Share Posted January 2, 2015 Hmm. Interesting information, but like you said, we only have one example to study, and as Holmes said, "It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." Quote Link to comment Share on other sites More sharing options...
DShomshak Posted January 3, 2015 Report Share Posted January 3, 2015 Oh -- Heller also believes that jovian planets could have Earth-sized moons, and these could be habitable, or even superhabitable. Their interiors would be heated by tidal stresses rather than radioactivity, so that factor would be removed. Heller's article has a bibliogaphy: Habitable Climates: The Influence of Obliquity. David S. Spiegel, Kristen Menou and Caleb A. Scharf in Astrophysical Journal, vol. 691, No. 1, pages 596-610; Jan. 20, 2009. http://iopscience.iop.org/0004-637X/691/1/596/article Exomoon Habitability Constrained by Illumination and Tidal Heating. Rene' Heller and Rory Barnes in Astrobiology, vol. 13, No. 1, pages 18-46; 2013. http://arxiv.org/abs/1209.5323 Habitable Zone Lifetimes of Exoplanets around Main Sequence Stars. Andrew J. Rushby, Mark W. Claire, Hugh Osborn and Andrew J. Watson in Atrobiology, vol. 13, No. 9, pages 833-849; Sep. 18, 2013. [Didn't give a URL] Superhabitable Worlds. Rene' Heller and John Armstrong in Astrobiology, Vol. 14, No. 1, pages 50-66; Jan. 16, 2014. http://arxiv.org/abs/1401.2392 Dean Shomshak L. Marcus 1 Quote Link to comment Share on other sites More sharing options...
tkdguy Posted January 3, 2015 Author Report Share Posted January 3, 2015 Not news, but a nice short video ISS passing in front of the Moon Quote Link to comment Share on other sites More sharing options...
Jhaierr Posted January 5, 2015 Report Share Posted January 5, 2015 Mystery object near black hole Quote Link to comment Share on other sites More sharing options...
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