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Assorted Personal Notations, Essays, and Other Jottings

Posts Tagged ‘extraterrestrial life

[LINK] “Is There a Kraken in Kraken Mare? What Kind of Life Would We Find on Titan?”

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At Universe Today, Paul Patton speculates about plausible biochemistries for life on Titan.

Could there be life on Saturn’s large moon Titan? Asking the question forces astrobiologists and chemists to think carefully and creatively about the chemistry of life, and how it might be different on other worlds than it is on Earth. In February, a team of researchers from Cornell University, including chemical engineering graduate student James Stevenson, planetary scientist Jonathan Lunine, and chemical engineer Paulette Clancy, published a pioneering study arguing that cell membranes could form under the exotic chemical conditions present on this remarkable moon.

In many ways, Titan is Earth’s twin. It’s the largest moon in the solar system and bigger than the planet Mercury. Like Earth, it has a substantial atmosphere, with a surface atmospheric pressure a bit higher than Earth’s. Besides Earth, Titan is the only object in our solar system known to have accumulations of liquid on its surface. NASA’s Cassini space probe discovered abundant lakes and even rivers in Titan’s polar regions. The largest lake, or sea, called Kraken Mare, is larger than Earth’s Caspian Sea. Researchers know from both spacecraft observations and laboratory experiments that Titan’s atmosphere is rich in complex organic molecules, which are the building blocks of life.

All these features might make it seem as though Titan is tantalizingly suitable for life. The name ‘Kraken’, which refers to a legendary sea monster, fancifully reflects the eager hopes of astrobiologists. But, Titan is Earth’s alien twin. Being almost ten times further from the sun than Earth is, its surface temperature is a frigid -180 degrees Celsius. Liquid water is vital to life as we know it, but on Titan’s surface all water is frozen solid. Water ice takes on the role that silicon-containing rock does on Earth, making up the outer layers of the crust.

The liquid that fills Titan’s lakes and rivers is not water, but liquid methane, probably mixed with other substances like liquid ethane, all of which are gases here on Earth. If there is life in Titan’s seas, it is not life as we know it. It must be an alien form of life, with organic molecules dissolved in liquid methane instead of liquid water. Is such a thing even possible?

It is, actually.

Written by Randy McDonald

October 3, 2015 at 3:59 am

[BLOG] Some Tuesday links

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  • blogTO notes that Toronto’s old City Hall may yet become a shopping mall once the courts move out.
  • The Dragon’s Gaze notes that worlds without plate tectonics are doomed to stop being habitable, and looks at different kinds of cosmic ray environments.
  • The Dragon’s Tales notes the Iranian buildup in Syria.
  • A Fistful of Euros has a reading list for Jeremy Corbyn.
  • Otto Pohl talks about the historic role of German minorities in Africa and Asia.
  • The Russian Demographics Blog shares a map of the Middle East’s Kurdish populations.
  • Spacing Toronto looks at campus safety in the age of threatening tweets.
  • Towleroad notes Michael Sam stating he could have had a better NFL career had he not come out.
  • Transit Toronto notes the TTC has taken its tenth new streetcar into service.
  • The Volokh Conspiracy looks at intersections between assisted suicide and religious liberty.
  • Window on Eurasia notes controversy in Belarus over a Russian military base and looks at Circassians in Syria.

[BLOG] Some Monday links

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  • blogTO looks at Queen and Bay in the 1960s and examines the PATH in the 1970s.
  • Centauri Dreams suggests that beamed power might be detectable by SETI.
  • The Dragon’s Tales looks at ancient salmon fishing in Alaska and notes the state of the Ukrainian war.
  • The Everyday Sociology Blog considers the extent to which crime can warp societies.
  • Far Outliers notes the heckling women protesters of Kyrgyzstan.
  • Language Log shares a bad translation of into English from Chinese.
  • Lawyers, Guns and Money notes how Indonesian drilling triggered a mud volcano.
  • Marginal Revolution looks at cap and trade in China and wonders why deflation has returned to Japan.
  • The Russian Demographics Blog maps abortion in Europe.
  • Savage Minds shares a list that is also an ethnography.
  • Towleroad notes the appearance of PrEP on American television.
  • Window on Eurasia criticizes Putin’s diplomatic strategies, notes that there are three million Muslims in Moscow, looks at the controversy surrounding Syrian Circassian refugees, notes some Russian tourists are now saying they are Belarusian, and notes the challenges of Belarus.

[LINK] On the waters of Mars

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Chelsea Leu’s Wired article was the first to appear in my RSS feed, describing the discovery of water on that world.

We’re not talking gushing rivers or oceans here. These scientists have been investigating “recurring slope lineae,” patches of precipitated salt that appear to dribble down Mars’ steep slopes like tears rolling gently down a cheek. Planetary scientists hypothesized that the streaky formations were products of the flow of water, but they didn’t have concrete, mineralogical evidence for that idea until now, says Lujendra Ojha, a scientist at Georgia Tech who first spotted the lineae back in 2010. In a new Nature Geoscience paper, published online today, Ojha and his colleagues present “smoking gun validation” that it was liquid water flowing on Mars’ surface that formed these tear stains.

Ojha and his team have watched these lineae form every Martian summer, growing wider week after week until they slowly fade come winter—exactly the times and places where conditions are right for liquid water to exist on Mars. Plus, the surface is crusted with salt, which could help stabilize liquid water so it doesn’t boil or freeze.

Ojha notes that they haven’t actually observed water flowing on Mars. The team took their data from the CRISM instrument on the Mars Reconnaisance Orbiter, which, frustratingly, only observes the surface every day at 3 pm. That’s when Mars is at its hottest and driest, so any liquid water oozing on the surface would have long since evaporated by the time MRO laid eyes on it.

CBC went into more detail about the potential implications of this water for life and its sources.

[The team] added that on Earth, similar brines offer “the only known refuge for active microbial communities” in the driest parts of Chile’s Atacama Desert.

On Mars, such brines could provide “transiently wet conditions near surface,” the researchers said. However, they cautioned that the amount of water may be too low to support known organisms that exist on Earth.

The researchers said they still don’t know where the water might be coming from – it’s probably not from melting ice, since the streaks are found near Mars’s equator, where it’s unlikely there could be any ice near the surface.

It could be coming directly from the atmosphere, but researchers aren’t sure if there’s enough water vapour in Mars’s atmosphere for that to happen. They might also come from a local aquifer, but since aquifers tend to be low-lying, that doesn’t explain why some of the streaks extend all the way up to the tops of local peaks. They suggested that the water source might be different for different slope lineae.

Even this discovery still means that Mars is a profoundly inhospitable world. The recent discovery of perchlorates underlines this issue. It does make it a bit less inhospitable, a less sere world.

Written by Randy McDonald

September 28, 2015 at 5:20 pm

[BLOG] Some Wednesday links

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  • blogTO notes that the Toronto Eaton Centre is set to be subtly renamed.
  • Centauri Dreams notes the absence of evidence for extragalactic supercivilizations.
  • The Dragon’s Gaze observes a new observatory that should be able to detect Earth-like worlds around red dwarfs and links to a paper describing how dwarf planets can heat Kuiper belts.
  • The Dragon’s Tales notes evidence suggesting the solar system could have ejected a gas giant, notes Canada is on the verge of buying French Mistrals, and looks at a blockade of Crimea by Crimean Tatars and right-wing Ukrainian nationalists.
  • Language Hat links to John McWhorter’s history of Aramaic.
  • Language Log looks at the controversy in South Korea on using Chinese characters in education.
  • Languages of the World looks at how different languages address god.
  • The Planetary Society Blog notes the current state of our knowledge and planning for Uranus and Neptune.
  • pollotenchegg maps language identity in early Soviet Ukraine.
  • The Power and the Money speculates as to why Russia is in Syria, and comes up with little that is reassuring.
  • The Russian Demographics Blog notes statistics on Muslim pilgrimages to Mecca.
  • Spacing Toronto suggests that an answer to the Gardiner East can be found in the rail corridor.
  • Window on Eurasia looks at the Russian deployment in Syria, speculates about future intentions in Central Asia and actual issues with Belarus, and suggests a turn to China will not help Asian Russia.
  • Zero Geogrpahy maps the generation of academic knowledge.

[BLOG] Some Friday links

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  • The Boston Globe‘s Big Picture reports on Olympics evictions in Brazil, compares school life in Boston and Haiti, and follows an elderly man climbing Mount Washington.
  • blogTO suggests jets will not be coming to the Toronto Island airport and argues the city is unlikely to legalize Uber.
  • The Broadside Blog examines the staggering level of income inequality in the United States.
  • Centauri Dreams considers, in real-life and science fiction, the problems with maintaining artificial economies and notes the complexities of the Pluto system.
  • Crooked Timber notes the problems of organized labour and Labour in the United Kingdom.
  • The Dragon’s Gaze notes how atmospheric oxygen may not automatically point to the sign of life.
  • The Dragon’s Tales maps volcanic heat flow on Io and wonders if that world has a subsurface magna ocean
  • Far Outliers notes a popular thief in post-Soviet Kyrgyzstan and looks at the politicization of the German military after the 1944 coup.
  • Geocurrents calls for recognizing the independence of Iraqi Kurdistan and Somaliland and looks at the geography of American poverty.
  • Language Log notes Sinified Japanese.
  • Lawyers, Guns and Money examines the complexities of race and history in New Mexico.
  • Marginal Revolution notes that India unlike China cannot sustain global growth, approves of Snyder’s Black Earth, and notes poor economic outcomes for graduates of some American universities.
  • Otto Pohl is not optimistic about Ghana’s economic future.
  • The Planetary Society Blog evaluates the latest images from Mars.
  • pollotenchegg evaluates the 1931 Polish census in what is now western Ukraine.
  • The Power and the Money’s Noel Maurer looks at why Syrian refugees will not be resettled in South America and observes that Mexico has birthright citizenship.
  • Cheri Lucas Rowlands describes the negative relationship for her between blogging and writing.
  • The Russian Demographics Blog examines rising mortality in Ukraine and notes changing ethnic compositions of Tajikistan’s populations.
  • Savage Minds talks about the importance of teaching climate change in anthropology.
  • Transit Toronto notes Toronto now has nine new streetcars.
  • Whatever’s John Scalzi considers the situation of poor people who go to good schools.
  • Window on Eurasia notes the lack of Russian nationalism in the Donbas, observes the scale of the refugee problem in Ukraine, and looks at Russian alienation of Moldova.

[BLOG] Some Friday links

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  • The Broadside Blog’s Caitlin Kelly talks about what it means to be an international migrant or refugee.
  • Centauri Dreams considers ways to detect nitrogen in the atmospheres of exoplanets.
  • Crooked Timber notes the importance of being a teacher.
  • The Dragon’s Tales observes reports that China is building a third aircraft carrier.
  • Geocurrents considers the extent to which support for national self-determination is an ideological issue, looking at Kurdistan and Balochistan.
  • Languages of the World criticizes the advice of the Strunk and White Style Manual.
  • Lawyers, Guns and Money notes that children of union workers do well.
  • The Planetary Society Blog shares images of Ceres.
  • Otto Pohl shares a new article on Crimean Tatars.
  • The Power and the Money hosts a post by Logan Ferree talking about the role Trump may play in the Republican primary election.
  • The Russian Demographics Blog notes the sphere of influence of the Russian language.
  • Savage Minds has an anthropological take on turmoil in Taiwan.
  • Spacing Toronto discusses strollers on mass transit.
  • The Volokh Conspiracy suggests Kim Davis did not have to go to jail for contempt of court.
  • Window on Eurasia suggests Ukraine can play a critical role for Russian dissidents and notes why Russia cannot annex the Donbas.

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