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Posts Tagged ‘extraterrestrial life

[BLOG] Some Wednesday links

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  • Bad Astronomy’s Phil Plait mourns the death of Apollo astronaut Gene Cernan and calls for a return to the Moon.
  • Beyond the Beyond’s Bruce Sterling wonders what future historiography will look like when it’s automatically assumed that British imperialism in South Asia was a bad thing.
  • blogTO highlights an impressive new condo tower planned for Mississauga.
  • D-Brief looks at how a literal heartbeat can transform the perception of an individual by race.
  • The Dragon’s Gaze links to a paper examining the potential for exoplanets orbiting red dwarfs to be habitable, finding that there seem to be no deal-breakers.
  • Language Hat shares the reflections of Russian-born author Boris Fishman who reads his novel, written in English, translated into the Russian.
  • Lawyers, Guns and Money links to a paper looking at the potential for industrial espionage to actually pay off.
  • The LRB Blog considers what will happen to Cuban migration now that Cuban migrants to the United States have no special status.
  • The NYRB Daily looks at post-revolutionary Cairo through film.
  • Savage Minds considers the grounds for potentially treating artificial intelligences as people.
  • Torontoist looks at two rival schools of medicine in 19th century Toronto.
  • The Volokh Conspiracy notes that Washington D.C.’s Freedom Plaza can be cleared of protests.
  • Window on Eurasia notes the potential financial catastrophe of Russia’s declining villages, and looks at Belarus’ national identity.

[LINK] “New Study Says Proxima b Could Support Life”

Universe Today’s Matt Williams reports on a paper suggesting that Proxima Centauri b could potentially support life, so long as its atmosphere and magnetosphere are sufficiently dense to ward off charged particles from its sun.

[W]hile some research has cast doubt on the possibility that Proxima b could indeed support life, a new research study offers a more positive picture. The research comes from the Blue Marble Space Institute of Science (BMSIS) in Seattle, Washington, where astrobiologist Dimitra Atri has conducted simulations that show that Proxima b could indeed be habitable, assuming certain prerequisites were met.

Dr. Atri is a computational physicist whose work with the BMSIS includes the impacts of antiparticles and radiation on biological systems. For the sake of his study – “Modelling stellar proton event-induced particle radiation dose on close-in exoplanets“, which appeared recently in the Monthly Notices of the Royal Astronomical Society Letters – he conducted simulations to measure the impact stellar flares from its sun would have on Proxima b.

To put this perspective, it is important to note how the Kepler mission has found a plethora of planets orbiting red dwarf stars in recent years, many of which are believed to be “Earth-like” and are close enough to their suns to have liquid water on their surfaces. However, red dwarfs have a number of issues that do not bode well for habitability, which include their variable nature and the fact they are cooler and fainter than other classes of stars.

This means that any planet close enough to orbit within a red dwarf’s habitable zone would be subject to powerful solar flares – aka. Stellar Proton Events (SPEs) – and would likely be tidally-locked with the star. In other words, only one side would be getting the light and heat necessary to support life, but it would be exposed to a lot of solar protons, which would interact with its atmosphere to create harmful radiation.

As such, the astronomical community is interested in what kinds of conditions are there for planets like Proxima b so they might know if life has (or had) a shot of evolving there. For the sake of his study, Dr. Atri conducted a series of probability (aka. Monte Carlo) simulations that took into account three factors – the type and size of stellar flares, various thicknesses of the planet’s atmosphere and the strength of its magnetic field.

[. . .] Atri found that the existence of a strong magnetic field, which would also ensure that the planet has a viable atmosphere, would lead survivable conditions. While the planet would still experience a spike in radiation whenever a superflare took place, life could survive on a planet like Proxima b in the long run. On the other hand, a weak atmosphere or magnetic field would foretell doom.

Written by Randy McDonald

December 22, 2016 at 10:30 pm

[LINK] “Alien life could thrive in the clouds of failed stars”

Science Magazine‘s Joshua Sokol shares the wonderfully plausibly bizarre idea of alien life floating in the upper atmospheres of brown dwarfs.

There’s an abundant new swath of cosmic real estate that life could call home—and the views would be spectacular. Floating out by themselves in the Milky Way galaxy are perhaps a billion cold brown dwarfs, objects many times as massive as Jupiter but not big enough to ignite as a star. According to a new study, layers of their upper atmospheres sit at temperatures and pressures resembling those on Earth, and could host microbes that surf on thermal updrafts.

The idea expands the concept of a habitable zone to include a vast population of worlds that had previously gone unconsidered. “You don’t necessarily need to have a terrestrial planet with a surface,” says Jack Yates, a planetary scientist at the University of Edinburgh in the United Kingdom, who led the study.

Atmospheric life isn’t just for the birds. For decades, biologists have known about microbes that drift in the winds high above Earth’s surface. And in 1976, Carl Sagan envisioned the kind of ecosystem that could evolve in the upper layers of Jupiter, fueled by sunlight. You could have sky plankton: small organisms he called “sinkers.” Other organisms could be balloonlike “floaters,” which would rise and fall in the atmosphere by manipulating their body pressure. In the years since, astronomers have also considered the prospects of microbes in the carbon dioxide atmosphere above Venus’s inhospitable surface.

Yates and his colleagues applied the same thinking to a kind of world Sagan didn’t know about. Discovered in 2011, some cold brown dwarfs have surfaces roughly at room temperature or below; lower layers would be downright comfortable. In March 2013, astronomers discovered WISE 0855-0714, a brown dwarf only 7 light-years away that seems to have water clouds in its atmosphere. Yates and his colleagues set out to update Sagan’s calculations and to identify the sizes, densities, and life strategies of microbes that could manage to stay aloft in the habitable region of an enormous atmosphere of predominantly hydrogen gas. Sink too low and you are cooked or crushed. Rise too high and you might freeze.

On such a world, small sinkers like the microbes in Earth’s atmosphere or even smaller would have a better chance than Sagan’s floaters, the researchers will report in an upcoming issue of The Astrophysical Journal. But a lot depends on the weather: If upwelling winds are powerful on free-floating brown dwarfs, as seems to be true in the bands of gas giants like Jupiter and Saturn, heavier creatures can carve out a niche. In the absence of sunlight, they could feed on chemical nutrients. Observations of cold brown dwarf atmospheres reveal most of the ingredients Earth life depends on: carbon, hydrogen, nitrogen, and oxygen, though perhaps not phosphorous.

Written by Randy McDonald

December 10, 2016 at 8:30 pm

[BLOG] Some Tuesday links

  • ‘Apostrophen’s ‘Nathan Smith talks about when it is appropriate to judge a book by its blurb.
  • Beyond the Beyond examines the remarkable scandal in South Korea involving with the cult and its control over the country’s president.
  • blogTO notes unreasonably warm weather in Toronto this November.
  • Dangerous Minds shares a corporate sales video from the early 1990s for Prince’s studio.
  • The Dragon’s Gaze notes the effect of Proxima Centauri on planetary formation around Alpha Centauri A and B.
  • The Extremo Files notes unorthodox ways of finding life.
  • Language Log talks about the language around Scotland and Northern Ireland and their relationship as complicated by Brexit.
  • Marginal Revolution links to a paper suggesting inheritances reduce inequality.
  • Savage Minds talks about an anarchist archaeology.
  • The Volokh Conspiracy considers a controversy at the Library of Congress.

[BLOG] Some Wednesday links

  • Beyond the Beyond links to an interview with Darran Anderson, a writer of cartographic fiction.
  • Centauri Dreams notes that 2028 will be a time when microlensing can b used to study the area of Alpha Centauri A.
  • The Crux engages with the question of whether or not an astronaut’s corpse could seed life on another planet.
  • The Dragon’s Gaze links to a study that gathers together signals for planetary companions orbiting nearby stars.
  • Joe. My. God. notes that the only gay bar in Portland, Maine, is set to close.
  • Language Log notes the proliferation of Chinese characters and notes that a parrot could not be called to the stand in Kuwait.
  • Lawyers, Guns and Money notes that the last time the Chicago Cubs won, Germany was an empire.
  • The Map Room Blog notes the discovery of an ancient stone map on the Danish island of Bornholm.
  • The Planetary Society Blog examines some of the New Horizons findings of Pluto.
  • The Power and the Money’s Noel Maurer argues that Venezuela is now a dictatorship.
  • Towleroad notes</a. controversy over a gay Utahn senator's visit to Iran.
  • Window on Eurasia notes a Russian cleric’s call for the children of ethnically mixed marriages in Tatarstan to be legally identified as Russians.

[LINK] “Was Venus the first habitable planet in our solar system?”

The Guardian‘s Hannah Devlin reports on new models of Venus’ environment which suggest this world was very broadly Earth-like well into the history of solar system. This is tantalizing, not least because of the prospects for life.

Its surface is hot enough to melt lead and its skies are darkened by toxic clouds of sulphuric acid. Venus is often referred to as Earth’s evil twin, but conditions on the planet were not always so hellish, according to research that suggests it may have been the first place in the solar system to have become habitable.

The study, due to be presented this week at the at the American Astronomical Society Meeting in Pasadena, concludes that at a time when primitive bacteria were emerging on Earth, Venus may have had a balmy climate and vast oceans up to 2,000 metres (6,562 feet) deep.

Michael Way, who led the work at the Nasa Goddard Institute for Space Studies in New York City, said: “If you lived three billion years ago at a low latitude and low elevation the surface temperatures would not have been that different from that of a place in the tropics on Earth,” he said.

The Venusian skies would have been cloudy with almost continual rain lashing down in some regions, however. “So while you might get nice sunsets you would have mostly overcast skies during the day and precipitation,” Way added.

[. . .]

Way and colleagues simulated the Venusian climate at various time points between 2.9bn and 715m years ago, employing similar models to those used to predict future climate change on Earth. The scientists fed some basic assumptions into the model, including the presence of water, the intensity of the sunlight and how fast Venus was rotating. In this virtual version, 2.9bn years ago Venus had an average surface temperature of 11C (52F) and this only increased to an average of 15C (59F) by 715m years ago, as the sun became more powerful.

Written by Randy McDonald

October 19, 2016 at 9:30 pm

[BLOG] Some Thursday links

  • blogTO notes that 1975 was a formative year for Toronto.
  • Centauri Dreams speculates about the oceans of Pluto and Saturn’s Dione.
  • Crooked Timber talks about Hannah Arendt’s arguments about the importance of bearing testament.
  • D-Brief looks at the cnyodont, an extinct reptile ancestral to mammals.
  • Dangerous Minds shares photos of Patti Smith.
  • The Dragon’s Gaze suggests that K-class dwarf stars are best for life.
  • Language Log looks at a merging of Wu and Mandarin Chinese on signage.
  • Lawyers, Guns and Money reports on how supply chains can hide corporations from responsibility.
  • The Volokh Conspiracy notes an American court ruling to the effect that barring Syrian refugees is unconstitutional discrimination.
  • Window on Eurasia reports on collapsing life expectancy in many Russian regions, looks at Russia’s withdrawal from the plutonium agreement with the United States, and criticizes American policy towards Belarus and Lukashenka.