Enceladus

[Recusant]

Enceladus is one of the moons of Saturn. There is strong evidence that there is a warm liquid water ocean under the ice surface of the moon. Last year, Dave quietly added a post to the abiogenensis thread, linking to a story in Scientific American about an observation of complex organic molecules in plumes coming from Enceladus (there is an access token link to the full paper in Nature in the final sentence of the Scientific American article). This observation was preceded by another which indicated that there were active hydrothermal vents in the ocean under the ice (popular science article and a paper in Science).



Since Dave's post there has been more news from Enceladus. In October of this year, additional organic compounds were found.

"New Organic Compounds Found in Enceladus Ice Grains" | JPL

Grains
In this image captured by NASA's Cassini spacecraft in 2007, the plumes of Enceladus are clearly visible. The moon is nearly in front of the Sun from Cassini's viewpoint.Credit: NASA/JPL/Space Science Institute
› Full image and caption
New kinds of organic compounds, the ingredients of amino acids, have been detected in the plumes bursting from Saturn's moon Enceladus. The findings are the result of the ongoing deep dive into data from NASA's Cassini mission.

Powerful hydrothermal vents eject material from Enceladus' core, which mixes with water from the moon's massive subsurface ocean before it is released into space as water vapor and ice grains. The newly discovered molecules, condensed onto the ice grains, were determined to be nitrogen- and oxygen-bearing compounds.

On Earth, similar compounds are part of chemical reactions that produce amino acids, the building blocks of life. Hydrothermal vents on the ocean floor provide the energy that fuels the reactions. Scientists believe Enceladus' hydrothermal vents may operate in the same way, supplying energy that leads to the production of amino acids.

"If the conditions are right, these molecules coming from the deep ocean of Enceladus could be on the same reaction pathway as we see here on Earth. We don't yet know if amino acids are needed for life beyond Earth, but finding the molecules that form amino acids is an important piece of the puzzle," said Nozair Khawaja, who led the research team of the Free University of Berlin. His findings were published Oct. 2 in the Monthly Notices of the Royal Astronomical Society.

[. . .]

The new findings complement the team's discovery last year of large, insoluble complex organic molecules believed to float on the surface of Enceladus' ocean. The team went deeper with this recent work to find the ingredients, dissolved in the ocean, that are needed for the hydrothermal processes that would spur amino acid formation.

"Here we are finding smaller and soluble organic building blocks - potential precursors for amino acids and other ingredients required for life on Earth," said co-author Jon Hillier.

"This work shows that Enceladus' ocean has reactive building blocks in abundance, and it's another green light in the investigation of the habitability of Enceladus," added co-author Frank Postberg.

[Continues . . .]

The most recent story is about a proposed mechanism behind the existence of the so-called "tiger stripes" on the south pole of Enceladus. These are large, persistent fissures, called sulci (singular sulcus), Latin for "furrow" or "groove."

A closeup of the four 80-mile-long rifts near Enceladus's south pole (white cross).
These "tiger stripes"are the source of its gas-and-particle plumes. Blue tints in this
false-color view from Cassini indicate an icy surface covered with coarse grains and boulders.
Image Credit: NASA / JPL / Space Science Inst.
[From Sky and Telescope]

"How Enceladus got its water-spewing tiger stripes" | Science

Researchers say they have solved a long-standing mystery about Saturn's tiny, frozen moon Enceladus: why its south pole features long, water-spewing geysers known as tiger stripes. The study could also help explain why these unique formations aren't seen on any other satellite in the solar system.

Enceladus became a star attraction in 2005, when NASA's Cassini mission photographed enormous jets of water ice and vapor emanating from four parallel slashes near its south pole. Since then, researchers have detected organic molecules and hydrogen in the jets—potential food for microbes—making Enceladus one of the top destinations in the search for life elsewhere in the Solar System. The stripes, named Baghdad, Cairo, Damascus, and Alexandria after locations in the One Thousand and One Nights collection of Middle Eastern folktales, are 130 kilometers long and are spaced roughly 35 kilometers apart—rather large features on a moon only 500 kilometers in diameter. Nobody quite understood their origin, or why they were only seen at one pole.

In 2006, planetary scientist Francis Nimmo of the University of California, Santa Cruz, posited that the stripes formed elsewhere on the moon and then migrated to the south pole after a hot spot welled up internally, creating a low-density bubble that knocked the world off kilter. But a paper posted this week [mid-November, 2019] on the preprint server arXiv tells a potentially more satisfying creation story.

As it orbits around Saturn, Enceladus experiences gravitational tidal forces that squeeze and heat it. Cassini data had already shown that a liquid water ocean sits underneath the outer ice shell, which is thinnest at the north and south poles. According to the new study, led by Douglas Hemingway of the Carnegie Institution for Science in Washington, D.C., as the moon cooled over time and some of the ocean water refroze, the new ice generated strain that built up in the surface until it broke. "It's like your pipes freezing on a cold day," says Nimmo, who was not involved in the study.

The thin polar ice was the most likely place for a crack to form, though it seems to be a matter of chance whether the first stripe burst into being at the north or south pole. But according to the study, once one large fracture appeared, the ice pressure was relieved, suppressing the creation of another furrow on the opposing pole.

That first fissure, extending down to the ocean, allowed a geyser to spray snow on its two flanks. The weight of this extra material produced more strains. In their study, the researchers calculate that these forces should have cracked additional grooves on either side, roughly 35 kilometers from the original one.

[Continues . . .]

[Bluenose]

As, I believe, Arthur C. Clarke once said, the universe is not only stranger than we imagine, it is stranger than we can imagine.

[Ecurb Noselrub]

If our Moon melted and was poured over this moon, you would have Enceladas with cheese sauce.

[Dark Lightning]

That would be "take me to your liederkranz", which isn't good with Mexican food. [/Isaac Asimov reference] Better than pouring Mercury on it, though.

[Ecurb Noselrub]

That would be "take me to your liederkranz", which isn't good with Mexican food. [/Isaac Asimov reference] Better than pouring Mercury on it, though.

For the record, the only good Tex-Mex food is in Texas, and the closer to the border, the better.

[Icarus]

Superb Mexican food can be found at an authentic Mexican grocery store at one side of my town.  All the grocery products are labeled in Spanish and a Gringo does not know what the hell is in those cans or bottles,  But they have a small restaurant that serves the real Mex cuisine.  They make outstanding and authentic dishes.  Better still, there is an adjoining bakery operated by real Mexicanos.  Their baked goods are seldom equaled in taste and quality.   Them wetbacks know how to prepare tasty food.

[Magdalena]

...Them wetbacks know how to prepare tasty food.

wetbacks?

Okay, honky.

[hermes2015]

...Them wetbacks know how to prepare tasty food.

wetbacks?

Okay, honky.

Heehee 1

[Dark Lightning]

We have "real" Mexican restaurants here in California. When I worked in Florida, there weren't any "Mexican" restaurants. I have no complaint about eating in a Cuban-themed restaurant, though. I used to joke with the guy who ran the stir-fry part of the cafeteria where I used to work (here in California). They alternated between "Italian" and "Asian". The difference was the type of starch used. You want pasta or rice in your stir-fry?  The vegetables and meats were still the same, and the spices were too.

[billy rubin]

here in small town appalachia when people want foreign food they go to pizza hut.

[Ecurb Noselrub]

...Them wetbacks know how to prepare tasty food.

wetbacks?

Okay, honky.

Forgive him, he knows not what he doeth. He's never had a witch turn him into a newt before.

[Davin]

...Them wetbacks know how to prepare tasty food.

wetbacks?

Okay, honky.

Forgive him, he knows not what he doeth. He's never had a witch turn him into a newt before.

I was turned into a newt. I got better.

[Magdalena]

Heehee 1

Forgive him, he knows not what he doeth. He's never had a witch turn him into a newt before.

I was turned into a newt. I got better.

[Tank]

...Them wetbacks know how to prepare tasty food.

wetbacks?

Okay, honky.

[Icarus]

An idiom often heard around automobile or motorcycle racers after they have said the wrong word or words, or made a dumb mistake on the track: "I stepped on my dick"

I will not use the word ----backs again in the presence of a witch or omnipotent butterfly.