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Mapping the ice on Mars that could support future missions – Ars Technica

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Enlarge / While we know of locations with ice on Mars, not all of them are in places we’d want to land.

Over the past couple decades, plans to go to Mars or return to the Moon for longer stays have gradually moved away from sci-fi tinged “what if” scenarios and shifted to something that resembles actual planning. And those plans invariably include extracting water from local ice deposits. This water would help support any astronauts during their stay, cutting down on the weight we’d have to shift out of Earth orbit. But it could also be a source of hydrogen that helps power the astronaut’s return trip to Earth.

That obviously means we want to land where the water is. On the Moon, this has meant focusing on the lunar poles, where deep craters create permanent shadows that can hold ice at temperatures where it’s stable. On Mars, the situation is considerably more complicated. In response to some NASA pilot funding, a team of scientists set up the SWIM projectM, for Subsurface Water Ice Mapping on Mars, to analyze the data. The project has now published a progress report showing a lot of ice deposits in areas we might want to land.

No poles, please

Whether or not water ice is stable on the Moon is determined entirely by sunlight exposure. As long as the Sun is never visible in a location, ice can survive. Mars is substantially more complicated, with an atmosphere that distributes heat and makes the temperature extremes far more moderate, plus orbital wobbles that ensure seasonal changes in temperature.

Mars does have polar ice, but the number of these deposits changes with the seasons (and a lot of it is frozen carbon dioxide). Further from the poles, there’s a region where temperatures would allow water ice to be stable, should it form there. But that region’s still far from the equator, which means more extreme cold and less solar energy for any photovoltaic equipment we might bring with us. Ideally, it would be nice to find some ice in temperate regions, and some reports have suggested locations where it might reside.

The SWIM team decided to take a far more comprehensive approach, using data from multiple instruments to try to establish a degree of confidence in the presence of water. To do so, the team developed its own ice scoring system.

That data comes from a number of instruments we’ve put in orbit above Mars. These include a neutron counter (neutrons scatter differently in ice than in rock) and two forms of radar that register the presence and depth of ice deposits. In addition, water tends to transmit heat poorly, so measurements of thermal flux can be indicative of its presence. Finally, by comparing them to glacial features on Earth, we can infer the presence of ice sheets from photographs of the terrain.

The authors created a scale for each of these five measurements that ranged from -1 (ice extremely unlikely) to 1 (ice almost certainly present). They then averaged the five, creating an overall score for the possible presence of ice. This allowed some methods to compensate for the shortcomings of others. For example, neutron scattering is extremely sensitive but could be blocked by a layer of dust less than a half-meter thick. Radar is less sensitive but can pick up material much further below the surface.

Given the researchers’ averaging technique, having one decisive reading would create a score of 0.2 if all the others methods were ambiguous. A score of 0.5 would mean that at least three of the methods strongly indicated the likely presence of water.

Go north, but not too far north

The first survey, reported here, has analyzed Mars’ northern hemisphere, from the equator up to 60º in latitude. There’s a small region along the east-west axis that’s not included, but otherwise, the data includes most of the area where we might reasonably expect to land. Adding to the appeal, the area includes a lot of open plains with suitable terrain for dropping something out of orbit.

To an extent, the data is consistent with what we already had suspected. Modeling of temperature profiles had identified the northern areas within this region as likely to be able to support ice, and the readings go up as you move north. An examination of some of the regions that the mapping project identified show that impacts in the area tend to expose ice (all 13 of the ice-exposing impacts that the researcher looked at were within one pixel of an area scored as likely to contain ice). Finally, a few of the areas identified by the mapping correspond to regions where the geography had already been interpreted as indicating a glacial history.

But the key finding is that some apparently ice-rich areas are further south than we’d have predicted based on temperature modeling alone. There were areas that scored above 0.5 at about 35º north of the martian equator, well into Mars’ relatively temperate zones (for comparison, it’s roughly where you’d find Morocco on Earth). One of the strongest signals is in an area called Arcadia Planitia, a very flat region covered by recent volcanic flows.

The team will presumably move on to the southern hemisphere next. And that’s going to be critical. While it’s great that we have a potential site well into the mid-latitudes of Mars, any landings there are going to be focused on the scientific case for exploring the area. Having multiple promising sites will give us the chance to pick and choose based on something beyond water availability.

Nature Astronomy, 2021. DOI: 10.1038/s41550-020-01290-z (About DOIs).

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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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