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More Evidence that Europa's Oceans Could be Habitable – Universe Today

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At first glance, Jupiter’s moon Europa doesn’t seem much like Earth. It’s a moon, not a planet, and it’s covered in ice. But it does have one important thing in common with Earth: a warm, salty ocean.

Now there’s even more evidence that Europa’s sub-surface ocean is habitable.

Scientists at NASA have developed a new model that supports Europa’s ability to support life. They presented their work at the 2020 Goldschmidt Conference, an annual conference on geochemistry and similar topics. It’s put on by the European Association of Geochemistry and the Geochemical Society.

“We believe that this ocean could be quite habitable for life.”

M. Melwani Daswani, Lead Author, JPL.

The work is titled “Evolution of volatiles from Europa’s interior into its ocean.” The authors are M. Melwani Daswani and S. D. Vance, from the Jet Propulsion Laboratory. Their work hasn’t been peer-reviewed yet.

Europa is one of Jupiter’s Galilean moons, the smallest of the four. Its brethren Ganymede and Callisto may also host sub-surface oceans, while the fourth moon, Io, does not.

Europa’s ocean is buried beneath a frozen crust approximately 10–30 km (6–19 mi) thick, and liquid ocean underneath that may be 100 km (62 miles) thick. The likely source of heat for this liquid is tidal flexing due to Jupiter’s monstrous mass, and Europa’s orbital resonance with the other Galilean moons. The evidence for this ocean stretches back to the Voyager and Galileo spacecraft.

These artist’s drawings depict two proposed models of the subsurface structure of Europa. Geologic features on the surface, imaged by the Solid State Imaging (SSI) system on NASA’s Galileo spacecraft, might be explained either by the existence of a warm, convecting ice layer, located several kilometers below a cold, brittle surface ice crust (top model), or by a layer of liquid water with a possible depth of more than 100 kilometers(bottom model). If a 100 kilometer (60 mile) deep ocean existed below a 15 kilometer (10 mile) thick Europan ice crust, it would be 10 times deeper than any ocean on Earth and would contain twice as much water as Earth’s oceans and rivers combined. Image: NASA/JPL.

This new research presented at the Goldschmidt Conference suggests that this sub-surface ocean formed endogenously. That means that it formed by breakdown of water-containing minerals due to either tidal forces or radioactive decay. That’s opposed to an exogenous ocean like Earth’s, which was likely delivered to Earth by comets and/or asteroids.

This work is primarily based on data from the Galileo mission, which arrived at Jupiter in 1995. Galileo performed a series of orbits of Jupiter and some of its moons, and the mission ended when it was de-orbited into Jupiter in 2003. But images from the Hubble Space Telescope played a role, too.

Newly re-processed Galileo images of Europa's surface show details that are visible in the variety of features on the moon's icy surface. This image of an area called Chaos Transition shows blocks that have moved and ridges possibly related to how the crust fractures from the force of Jupiter's gravity. Image Credit: NASA/JPL-Caltech/SETI Institute
Newly re-processed Galileo images of Europa’s surface show details that are visible in the variety of features on the moon’s icy surface. This image of an area called Chaos Transition shows blocks that have moved and ridges possibly related to how the crust fractures from the force of Jupiter’s gravity. Image Credit: NASA/JPL-Caltech/SETI Institute

“We were able to model the composition and physical properties of the core, silicate layer, and ocean,” said lead author Daswani in a press release. “We find that different minerals lose water and volatiles at different depths and temperatures. We added up these volatiles that are estimated to have been lost from the interior, and found that they are consistent with the current ocean’s predicted mass, meaning that they are probably present in the ocean.”

While many researchers think that tidal flexing is responsible for the heating, radioactive decay may play a role, too. But whatever the source, as the heat and pressure increased inside Europa, water-containing minerals broke down and released that water.

Some scientific thinking says that the water might be too acidic for life as we know it, due to higher concentrations of calcium, sulfate, and carbon dioxide. But this new modelling suggests that that was temporary, and the ocean became chloride rich over time.

“Europa is one of our best chances of finding life in our solar system.” 

M. MELWANI DASWANI, LEAD AUTHOR, JPL.

“Indeed it was thought that this ocean could still be rather sulfuric” said Daswani, “but our simulations, coupled with data from the Hubble Space Telescope, showing chloride on Europa’s surface, suggests that the water most likely became chloride rich. In other words, its composition became more like oceans on Earth. We believe that this ocean could be quite habitable for life.”

Artist's concept of a Europa Clipper mission. NASA plans to launch this mission in the 2020s. Credit: NASA/JPL
Artist’s concept of a Europa Clipper mission. NASA plans to launch this mission in the 2020s. Credit: NASA/JPL

Habitable is one thing, but inhabited is another. And that’s why there’s so much thinking about a mission to Europa to investigate further.

“Europa is one of our best chances of finding life in our solar system. NASA’s Europa Clipper mission will launch in the next few years, and so our work aims to prepare for the mission, which will investigate Europa’s habitability,” said Daswani. “Our models lead us to think that the oceans in other moons, such as Europa’s neighbor Ganymede, and Saturn’s moon Titan, may also have formed by similar processes. We still need to understand several points though, such as how fluids migrate through Europa’s rocky interior.”

“…what reliable flow of electrons could be used by alien life to power itself in the cold, dark depths?”

Steve Mojzsis, Professor of Geology at the University of Colorado.

The issue of habitability might boil down to one question. And it’s one that can only be answered by sending a spacecraft to the moon. In a press release, Steve Mojzsis, Professor of Geology at the University of Colorado, elaborated on that question as an independent commenter not involved in the research.

“A long-standing question over whether a “cloaked ocean” world like Europa could be habitable boils down to whether it can sustain a flow of electrons which might provide the energy to power life. What remains unclear is whether such icy moons could ever generate enough heat to melt rock; certainly interesting chemistry takes place within these bodies, but what reliable flow of electrons could be used by alien life to power itself in the cold, dark depths? A key aspect that makes a world “habitable” is an intrinsic ability to maintain these chemical disequilibria. Arguably, icy moons lack this ability, so this needs to be tested on any future mission to Europa.”

Europa’s surface is a frigid place. The temperature at the equator averages about 110 K (?160 °C; ?260 °F) and only about 50 K (?220 °C; ?370 °F) at the poles. That means its surface is as hard as rock. But while scientists know that the sub-surface ocean is warm, they don’t know its temperature.

Another re-processed Galileo image. This one is of an area called Crisscrossing Bands, and it shows ridges which may form when a crack in the surface opens and closes repeatedly. In contrast, the smooth bands shown here form where a crack continues pulling apart horizontally, producing large, wide, relatively flat features. Image Credit: NASA/JPL-Caltech/SETI Institute
Another re-processed Galileo image. This one is of an area called Crisscrossing Bands, and it shows ridges which may form when a crack in the surface opens and closes repeatedly. In contrast, the smooth bands shown here form where a crack continues pulling apart horizontally, producing large, wide, relatively flat features. Image Credit: NASA/JPL-Caltech/SETI Institute

Right now we only have a tantalizing taste of the nature of Europa’s ocean. There’ll be more studies and more modelling and simulating as time goes on, and that work is necessary. But only a mission to the moon can really answer our questions. (And it’ll probably pose a few more questions, too.)

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While the Europa Clipper will be an orbiter only, other conceptual missions go further. One concept calls for a nuclear-powered tunneling robot to get through the ice and study the ocean itself. Another suggested boring through the ice with lasers to get to the ocean. But those ideas are fanciful, for now, and face many obstacles.

We’ll be relying on the Clipper to answer our questions about Europa and its ocean. And unfortunately, we’re going to have to wait a few years for that.

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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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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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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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