Tuesday, April 11, 2017

Will NASA Say, On Thursday There Is Methane Being Produced -- In Enceladus' Subsurface Oceans?

. . .Under Mount Etna he lies,
It is slumber, it is not death;
he struggles at times to arise,
And above him the lurid skies
Are hot with his fiery breath. . . ."

Once again, it is with hope -- that we look out, into this clearing Spring night sky. . . it is ever thus, for us.

In two days' time, we will hear from NASA, as to the latest findings from Cassini's data, on Enceladus (imaged with Cassini, at right). Just read what AstroBiology has to say this evening [couldn't have said it better, myself]:

. . . .On Thursday NASA will announce evidence that hydrothermal activity on the floor of an ice-covered ocean on Saturn's moon Enceladus is most likely creating methane from carbon dioxide. The process is indicative of possible habitable zones within the ocean of Enceladus.

But before we go any further, "habitable" does not mean "inhabited". . . .

Interestingly, just as there are many mechanisms that could be operating on Enceladus that involve geochemistry (i.e. no life) there are some possible mechanisms that could be suggestive of biological processes. There are forms of life on Earth that use hydrogen to produce methane from and carbon dioxide in a process known as methanogenesis. As such, if similar conditions exist on Enceladus, the issue of habitability arises. But again, this could just be chemistry that happens without any living processes involved.

On our planet these hydrothermal vents often host complex ecologies with some microorganisms deriving energy directly from the mineralogical chemistry surrounding these vents instead of obtaining energy from the sun. In turn, larger life forms feed upon these microorganisms and entire communities can arise. Unlike the ecological interactions we are used to seeing on Earth's surface where life either depends directly on sunlight or eats life forms that depend on sunlight, these deep hydrothermal communities are able to operate without any energy input from the sun. There are also hydrothermal systems that operate near to - or at - the surface of Earth that also host forms of life that rely on chemistry instead of sunlight as an energy source. . . .

As to exquisite Cassini herself, earlier this morning NASA sent the command sequence to begin her final series of plunges through the openings in Saturn's rings -- the "grand finale". It took the signals 160 minutes to round-trip, in ping and response. That's at the speed of light -- so golden Cassini (writhing slowly in the darkness). . . is mighty far away.

Do click at right, to enlarge, and drink, drink in the dark chemistry there -- lustily -- from Longfellow's ode to Enceladus -- those are "words writ in water," indeed. . . . Chemistry. . . is served! And just like love -- life too, finds a way. . . So I too -- will. . . rise! smile -- g'night, all of good will. . . .



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