Posted on 02/22/2024 7:51:03 AM PST by Red Badger
Titan, as seen by Cassini. Image credit: NASA/JPL-Caltech/Univ. Arizona/Univ. Idaho
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Anew study looking at impact cratering on Titan has found bad news in the search for life on the moon, and potentially other icy moons of the Solar System as well.
Titan, Saturn's largest moon, is often thought of as a potential candidate for life. The moon is the only place in the Solar System – other than Earth – where liquids are known to be present on the surface, making up rivers, lakes and seas.
These water features are made of liquid hydrocarbons, the bulk of which is methane. More intriguing to scientists looking for life is the giant subsurface ocean, thought to be more than 12 times the volume of Earth's oceans, locked beneath the planet's icy crust and stretching 55 to 80 kilometers (35 to 50 miles) below the ground.
"Titan’s rivers, lakes and seas of liquid methane and ethane might serve as a habitable environment on the moon’s surface, though any life there would likely be very different from Earth’s life," NASA explains of the moon. "Titan could potentially harbor environments with conditions suitable for life – meaning both life as we know it (in the subsurface ocean) and life as we don’t know it (in the hydrocarbon liquid on the surface)."
Liquid water under the surface is of course promising for life, but for life to emerge you also need organics. It was thought that these ingredients could be delivered to the ocean below, where they could be swirled around and heated and potentially spark life via the impacts of space objects. The idea was that the surface – rich in organics – would mix with the subsurface ocean as objects impact the surface and melt pools of water in the ice. Being denser than the surrounding ice, this would then sink down to the subsurface ocean.
However, a study from the University of Western Ontario attempted to estimate how many comets impact the moon per year, and the quantity of organics which would be delivered to the subsurface ocean through these impacts. Unfortunately, the team found that the volume of glycine – the simplest amino acid – delivered to the ocean would only be around 7,500 kilograms (16,500 pounds), or around the weight of an adult elephant.
"One elephant per year of glycine into an ocean 12 times the volume of Earth's oceans is not sufficient to sustain life," astrobiologist Catherine Neish said in a press release. "In the past, people often assumed that water equals life, but they neglected the fact that life needs other elements, in particular carbon."
"This work shows that it is very hard to transfer the carbon on Titan's surface to its subsurface ocean –basically, it's hard to have both the water and carbon needed for life in the same place," Neish added.
Given that Titan has more organics on its surface than the other icy moons of Saturn and Jupiter, this puts a bit of a dampener on our search for life within the Solar System.
"Unfortunately, we will now need to be a little less optimistic when searching for extraterrestrial lifeforms within our own Solar System," Neish said. "The scientific community has been very excited about finding life in the icy worlds of the outer Solar System, and this finding suggests that it may be less likely than we previously assumed."
Nevertheless, there is still a little wiggle room. Life could be possible, for instance, if there were more organics on the surface than previously estimated, if organics could come from the core, or other processes could deliver organics from the surface to the ocean below.
"It is nearly impossible to determine the composition of Titan's organic-rich surface by viewing it with a telescope through its organic-rich atmosphere," Neish added. "We need to land there and sample the surface to determine its composition."
Fortunately, NASA plans to do just that with the Dragonfly mission, which will see a flying vehicle hop around the moon's surface. Neish, who is part of the Dragonfly team, says that this research could help identify interesting places to land.
"If all the melt produced by impacts sinks into the ice crust, we wouldn't have samples near the surface where water and organics have mixed. These are regions where Dragonfly could search for the products of those prebiotic reactions, teaching us about how life may arise on different planets," said Neish.
"The results from this study are even more pessimistic than I realized with regards to the habitability of Titan's surface ocean, but it also means that more interesting prebiotic environments exist near Titan's surface, where we can sample them with the instruments on Dragonfly."
The study is published in Astrobiology.
https://www.liebertpub.com/doi/full/10.1089/ast.2023.0055
Well, Duh Ping!........................
Scientists: Icy Moons May Contain Ice.
ALL THESE WORLDS ARE YOURS – EXCEPT EUROPA. ATTEMPT NO LANDING THERE
Science Fiction - in many ways, indistinguishable from modern science.
I’ve been looking for a detailed mechanism for spontaneous abiogenesis. A hypothesis or even a plausible conjecture would do. Something more than “a bunch of organic chemicals on a dead wet planet found each other, and so, naturally, poof there’s life”, which is all I’ve seen so far. Given all the alleged certainty that life is common throughout the universe, you’d think someone would have done better than that.
So . . . . . there's an elephant on the moon? Cool
One day a group of scientists got together and decided that man had come a long way and no longer needed God. So they picked one scientist to go and tell Him that they were done with Him.
The scientist walked up to God and said, “God, we’ve decided that we no longer need You. We’re at the point that we can clone people and do many miraculous things, we don’t need you here anymore, you can go your way “
God listened very patiently and kindly to the man. After the scientist was done talking, God said, “Very well, how about this? Let’s say we have a man-making contest?”
To which the scientist replied, “Okay, great!”
But God added, “Now, we’re going to do this just like I did back in the old days with Adam.”
The scientist said, “Sure, no problem,” and bent down and grabbed himself a handful of dirt.
God looked at him and said, “No, no! You go get your own dirt!”
NASA has dumbed itself down with all that diversity
In other news the Reptilian Alien scientists claimed there was no life on Terra.
Good post.
Science just fakes it until they make it.
Not so fast.
I *thought* Pluto had liquids on its surface. I double-checked and it turned out to be more of a quasi-solid liquid surface…more of a slurry.
Of course it is about 35 degrees Kelvin out there.
Nonetheless, it IS possible Pluto has a liquid surface. And yes, Pluto IS a planet.
And Titan. Maybe the no-doubt-highly-educated writer (or the editor, same prefix) of the piece meant to refer to liquid water?
Thanks Red Badger.
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On Titan there are some carbon compounds that are less than what predictions would suggest. They could be low because something is eating them. Life on Titan would be very different from life on Earth.
Ha. Or in this case, point to whatever dirt wherever you choose, don’t touch it, and get back to Me when it turns into a person, all by itself.
Life does not just ‘happen’.
If it did, it would still be doing it, every day.................
I feel this is a mistaken conclusion due to the fact they propose the organics MUST come from the surface to mix and mingle with the subsurface ocean(s).
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