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Assorted Personal Notations, Essays, and Other Jottings

Posts Tagged ‘extraterrestrial life

[LINK] “‘Venus Zone': The Anti-Habitable Area Around A Star That Can Breed Hell”

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Universe Today’s Elizabeth Howell writes about a new paper, “On the Frequency of Potential Venus Analogs from Kepler Data”, that examines the whole question of stellar Venus zones. Where must Venuses–broadly Earth-like but very hotel planets–be located in their planetary systems?

“We believe the Earth and Venus had similar starts in terms of their atmospheric evolution,” stated lead author Stephen Kane, an astronomer at San Francisco State University. “Something changed at one point, and the obvious difference between the two is proximity to the Sun.”

The habitable region around a star is poorly understood because scientists don’t quite know what conditions are necessary for life. It usually refers to the area where liquid water is possible, although this also depends on the climate of the planet itself. Clouds, terrain and atmospheric composition are just some of the variables that could affect habitability.

To better figure out where potential Venus-like exoplanets lurk, Kane’s team used data from the planet-hunting Kepler Space Telescope and examined solar flux — or how much solar energy a planet gets — to figure out where the Venus zone would be. The zone is then defined between two regions: where a planet could have the “runaway greenhouse effect” seen on Venus, and the spot where the planet is so close to its star that energy would wear away its atmosphere.

The first step would be pinpointing which planets reside within these zones. In future decades, astronomers could then examine the planetary atmospheres with telescopes to learn more about how they are composed — and how similar they are to Earth or Venus. Meanwhile, Kane’s team plans to model if carbon in the planet’s atmosphere could affect the boundaries of the zone.

Written by Randy McDonald

September 16, 2014 at 7:36 pm

[BLOG] Some Tuesday links

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  • Bad Astronomy’s Phil Plait notes a new study suggesting that the star Betelgeuse will go supernova not imminently, but rather in a hundred thousand years.
  • blogTO profiles midtown Toronto’s Merton Street.
  • Discover‘s Crux examines the most suitable potential locations for offworld colonies (Venus, the Moon, Mars).
  • The Dragon’s Gaze links to one paper suggesting that binary star systems might actually be better-suited to Earth-like worlds that solitary star systems like our our and links to another speculating about the patterns of light emitted by Earth-like worlds.
  • The Dragon’s Tales notes an archeological study suggesting that chocolate was eaten in the Mississippian civilization of Cahokia, and looks at an ongoing dispute over rocket development between France and Germany in the European Space Agency.
  • Languages of the World’s Asya Pereltsvaig looks at the ongoing disappearance of the Belarusian language.
  • Marginal Revolution notes the exceptional vulnerability of Scotland’s economy to its banking sector.
  • Personal Reflection’s Jim Belshaw reflects on the movement for statehood in the Australian region of New England in the light of the imminent Scottish referendum.
  • Torontoist notes a survey examining the issues of LGBT people in the Ontario police services.
  • Towleroad notes the lesbian couple married in Iowa after seventy years together.
  • The Volokh Conspiracy notes that the Northern Marianas are the only jurisdiction with a total handgun ban.
  • Window on Eurasia notes the progress of fascism in Russia, considers the consequences of the war for both Ukraine and Russia, and looks at growing concern elsewhere in the former Soviet space about Russia.

[LINK] “Plate tectonics found on Europa”

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Nature‘s Alexandra Witze summarizes recent research suggesting that plate tectonics are at work in Europa’s icy crust. Among other things, this makes it more likely that the oceans underneath the ice could support life.

If you have got an idea for how to study Europa, then NASA wants to hear from you.

The agency has no official plans for a mission to the Jovian moon, whose icy crust covers a watery ocean in which life could theoretically exist. But spurred by intense congressional interest and several recent discoveries, NASA is seeking ideas for instruments that could fly on a mission to Europa. The possibilities range from a stripped-down probe that would zip past the moon, to a carefully designed Jupiter orbiter that would explore Europa over many years.

The groundswell of enthusiasm is likely to be bolstered by the latest big news, reported on 7 September, that there may be giant plates of ice shuffling around on Europa — much as plates of rock do on Earth (S. A. Kattenhorn and L. M. Prockter Nature Geosci. http://dx.doi.org/10.1038/ngeo2245; 2014). Such active geology suggests that Europa’s icy surface is connected to its buried ocean — creating a possible pathway for salts, minerals and maybe even microbes to get from the ocean to the surface and back again.

Simon Kattenhorn, a geologist previously at the University of Idaho in Moscow, and Louise Prockter, a planetary scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, made the finding after combing through pictures from NASA’s Galileo spacecraft, which orbited Jupiter from 1995 to 2003. Most of its pictures of Europa are fairly blurry, but Kattenhorn and Prockter scrutinized one of the few regions of the moon for which high-resolution images exist.

They treated the images as though they were parts of a giant geological jigsaw puzzle, with ridges and bands and other features that have been split and separated by crustal movements, and tried to trace how the surface of Europa had transformed over time. “When we moved all the pieces back together, there was a big hole in the reconstruction, a sort of blank space,” says Kattenhorn. The missing portion, the scientists concluded, must have been somehow sucked down into the moon’s interior.

Written by Randy McDonald

September 8, 2014 at 7:33 pm

[BLOG] Some Wednesday links

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  • Anthropology.net reacts to the discovery of Neanderthal abstract carvings and what they say about the Neanderthal mind.
  • blogTO shares Toronto postcards from the 1980s and lists the five least used TTC subway stations.
  • Centauri Dreams reports that potentially habitable exoplanets Gliese 667Cc has been confirmed to exist.
  • Crooked Timber’s Corey Robin describes the continuing Steven Salaita affair, with another Crooked Timber post and one at Lawyers, Guns and Money providing more context.
  • The Dragon’s Gaze links to a paper placing HD 10180g in its star’s habitable zone and links to another making the case for the potential habitability of exomoons.
  • The Dragon’s Tales’ Will Baird is very concerned for the fate of Ukraine.
  • Language Log’s Victor Mair examines the pressing question of why Hello Kitty is not a cat.
  • Lawyers, Guns and Money looks at rape culture in England.
  • Marginal Revolution notes that Bolivians of different classes rarely marry each other and is relatively optimistic about the country’s future.
  • Spacing Toronto has a lovely picture of a track on a ride at the CNE under construction.
  • Window on Eurasia notes that Kazakhstan is ready to leave the Euriasian Union to protect its independence, argues that the Ukrainian war is sparing Tatarstan and North Caucasus attention, and examines the depopulation of Pskov oblast next to the Baltic States.
  • Yorkshire Ranter Alex Harrowell notes the strengths and weaknesses of the Islamic State as described in an article: a willingness to risk death isn’t always a plus.

[BLOG] Some Wednesday links

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  • io9 argues that it’s time to survey Uranus, notwithstanding its name.
  • blogTO describes the attractive-sounding art-friendly Harbord Laundry.
  • The Dragon’s Tales notes archeological evidence suggesting that Vanuatu was settled three thousand years ago.
  • Joe. My. God. has comments about the Burger King-Tim Horton’s merger that really bring American outrage over the shift of the resulting company to Canada for tax purposes home.
  • Lawyers, Guns and Money notes the creepy locker-room homophobias of ESPN.
  • Marginal Revolution notes that China is now officially building much more housing than it actually needs.
  • The Planetary Society Blog considers various designs for probes to Jupiter’s moon of Europa.
  • Torontoist and blogTO note that Yorkville institution the Coffee Mill is closing down.
  • The Volokh Conspiracy reacts critically to a survey claiming three-quarters of whites have no non-white friends.
  • Window on Eurasia notes Russian concern that support for federalism in Ukraine might spread to Russia, observes the prominent role of Tatars in fighting for Russia in the First World War, and refers to the explicit concerns of Nazarbayev that Kazakhization not be carried too quickly lest the country risk Ukraine’s fate.

[BLOG] Some Friday links

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  • blogTO wonders, in the aftermath of companies confiscating bicycles parked on city property, if Toronto should clearly mark off public and private space on its streets.
  • Centauri Dreams studies news that the Stardust probe may have captured bits of the interstellar medium.
  • The Dragon’s Gaze reports that sun-like Alpha Centauri A and B can both support planets in stable Earth-like orbits.
  • The Dragon’s Tales notes the impact of changing patterns of snowfall on Arctic ice.
  • Eastern Approaches studies Balkan volunteers in wars abroad, both that of Albanians in the Middle East and of Serbs for Russia in Ukraine.
  • Far Outliers looks at Japan’s farmer-soldiers on the late 19th century Hokkaido frontier.
  • Spacing Toronto favourably reviews the new psychogeography-themed book Unruly Places.
  • Understanding Society points to the massive success of a comparative statistical analysis of historical Eurasian populations.
  • Window on Eurasia links to a photo essay of an empty post-Olympics Sochi.
  • Writing Through the Fog’s Cheri Lucas Rowlands argues that modern social media hinders memoir writing, by making it too easy to publish quickly.
  • Wonkman points out that the problem with subtle homoeroticism in modern popular culture is that, well, it doesn’t need to be subtle any more. What needs to be hidden?

[BLOG] Some space-related links

  • Anders Sandberg notes how the book and film 2001 are touchstones still for what we might fear of our future.
  • Centauri Dreams touched on quite a few issues while I was offline, noting a proposed solar-sail probe to Halley’s Comet, notes the positive implications of geysers and liquid water for life on Enceladus, notes the exceptional distance of exoplanet Kepler-421b from its star and precisely measures the size and orbit of Kepler-93b and looks at the dryness of hot Jupiters and studies the misaligned gas discs of the stars of binary HK Tauri, and looks at ways to keep Earth-like planets orbiting red dwarfs habitable for hundreds of billions of years.
  • The Dragon’s Gaze notes that Gliese 1214b is an evaporating hot Neptune, looks at the search for rogue exoplanets in the Pleiades, mourns the non-existence of Gliese 581g and Gliese 481d, points to evidence that X-ray source IGR J17361-4441 was blocked partially and briefly by an exoplanet, looks at the search of exoplanets around nearbuy red dwarf stars, links to a reexamination of some Kepler exoplanet candidates and their stars by the Hubble space telescope, and notes that most worlds more than 1.6 times the radius of Earth are likely to be Neptunes.
  • At The Dragon’s Tales, the planet-reshaping impacts of the Late Heavy Bombardment on the early Earth are noted, as are forces acting on solar sails, as is a proposal to use the Voyager 1 spacecraft’s movements and signals to look for distant planets, as is a paper suggesting that Titan’s inner sea is as salty as the Earth’s.
  • The Planetary Society Blog notes (1, 2, 3) the Rosetta spacecraft’s rendezvous with its target comet, notes a conference examining the habitability of Mars, looks at an odd mountain on Vesta, and links to an inventive revisiting of Venera images of the Venus surface.
  • Progressive Download’s John Farrell celebrates the ESA’s Georges Lemaître ATV, named after a Belgian cosmologist of note.

Written by Randy McDonald

August 12, 2014 at 3:00 am

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