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Saturn’s largest moon most likely uninhabitable

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This image shows a flattened (Mercator) projection of the Huygens probe’s view of Saturn’s moon Titan from 10 kilometers altitude. The images that make up this view were taken on Jan. 14, 2005, with the descent imager/spectral radiometer onboard the European Space Agency’s Huygens probe. The Huygens probe was delivered to Titan by the Cassini spacecraft, managed by NASA’s Jet Propulsion Laboratory, Pasadena, Calif. Credit: ESA/NASA/JPL/University of Arizona photo

A study led by Western astrobiologist Catherine Neish shows the subsurface ocean of Titan—the largest moon of Saturn—is most likely a non-habitable environment, meaning any hope of finding life in the icy world is dead in the water.

This discovery means it is far less likely that space scientists and astronauts will ever find life in the , home to the four ‘giant’ planets: Jupiter, Saturn, Uranus and Neptune.

“Unfortunately, we will now need to be a little less optimistic when searching for extraterrestrial lifeforms within our own solar system,” said Neish, an Earth sciences professor. “The 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.”

The identification of life in the outer solar system is a significant area of interest for planetary scientists, astronomers and government space agencies like NASA, largely because many icy moons of the giant planets are thought to have large subsurface oceans of liquid . Titan, for example, is thought to have an beneath its icy that is more than 12 times the volume of Earth’s oceans.

“Life as we know it here on Earth needs water as a solvent, so planets and moons with lots of water are of interest when looking for ,” said Neish, a member of Western’s Institute for Earth and Space Exploration.

In the study, published in the journal Astrobiology, Neish and her collaborators attempted to quantify the amount of organic molecules that could be transferred from Titan’s organic-rich surface to its subsurface ocean, using data from impact cratering.

Comets impacting Titan throughout its history have melted the surface of the icy moon, creating pools of liquid water that have mixed with the surface organics. The resulting melt is denser than its icy crust, so the heavier water sinks through the ice, possibly all the way to Titan’s subsurface ocean.

Using the assumed rates of impacts on Titan’s surface, Neish and her collaborators determined how many comets of different sizes would strike Titan each year over its history. This allowed the researchers to predict the flow rate of water carrying organics that travel from Titan’s surface to its interior.

Neish and the team found the weight of organics transferred in this way is quite small, no more than 7,500 kg/year of glycine—the simplest amino acid, which makes up proteins in life. This is approximately the same mass as a male African elephant. (All biomolecules, like glycine, use carbon—an element—as the backbone of their molecular structure.)

“One elephant per year of glycine into an ocean 12 times the volume of Earth’s oceans is not sufficient to sustain life,” said Neish. “In the past, people often assumed that water equals life, but they neglected the fact that life needs other elements, in particular carbon.”

Other icy worlds (like Jupiter’s moons Europa and Ganymede and Saturn’s moon Enceladus) have almost no carbon on their surfaces, and it is unclear how much could be sourced from their interiors. Titan is the most organic-rich icy moon in the solar system, so if its subsurface ocean is not habitable, it does not bode well for the habitability of other known icy worlds.

“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,” said Neish.

Saturn's largest moon most likely uninhabitable
An artist’s rendering shows a Dragonfly quadcopter landing on the surface of Saturn’s moon Titan, unfolding its rotors and lifting off again to survey the landscape and atmosphere. Credit: Steve Gribben/Johns Hopkins

Flight of the Dragonfly

Despite the discovery, there is still much more to learn about Titan, and for Neish, the big question is, what is it made of?

Neish is a co-investigator on the NASA Dragonfly project, a planned 2028 spacecraft mission to send a robotic rotorcraft (drone) to the surface of Titan to study its prebiotic chemistry, or how formed and self-organized for the origin of life on Earth and beyond.

“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,” said Neish. “We need to land there and sample the surface to determine its composition.”

To date, only the Cassini–Huygens international space mission in 2005 has successfully landed a robotic probe on Titan to analyze samples. It remains the first spacecraft to land on Titan and the farthest landing from Earth a spacecraft has ever made.

“Even if the subsurface ocean isn’t habitable, we can learn a lot about prebiotic chemistry on Titan, and Earth, by studying the reactions on Titan’s surface,” said Neish. “We’d really like to know if interesting reactions are occurring there, especially where the organic molecules mix with liquid water generated in impacts.”

[embedded content]
Credit: JPL

When Neish started her latest study, she was worried it would negatively impact the Dragonfly mission, but it has actually led to even more questions.

“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.”

More information:
Catherine Neish et al, Organic Input to Titan’s Subsurface Ocean Through Impact Cratering, Astrobiology (2024). DOI: 10.1089/ast.2023.0055

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Saturn’s largest moon most likely uninhabitable (2024, February 14)
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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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