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Soon, 1 out of every 15 points of light in the sky will be a satellite – National Post

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THE CONVERSATION

This article was originally published on The Conversation, an independent and nonprofit source of news, analysis and commentary from academic experts. Disclosure information is available on the original site.

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Author: Samantha Lawler, Assistant professor of astronomy, University of Regina

I’m outside at my rural Saskatchewan farm, chatting with my neighbours who I’ve invited over to appreciate the night sky through my telescope. After exclamations and open-mouthed wonder over Saturn’s rings, and light that has been travelling through space for more than two million years to reach our eyes from the Andromeda Galaxy, our conversation inevitably turns to the pandemic, our work-from-home arrangements and complaints about rural internet. My neighbour casually mentions they’ve just switched to using Starlink for their internet provider.

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I glance up and notice a bright satellite moving across the sky, almost certainly a Starlink, since they now make up almost half of the nearly 4,000 operational satellites and they’re extremely bright. I take a deep breath and carefully consider how to discuss the substantial cost that we’re all going to have to pay for Starlink internet.

I don’t blame my neighbours for switching. Here, as in many rural parts of North America, there aren’t great internet options, and with many people working and taking classes from home during the pandemic, anything that makes life easier is immediately accepted.

But I know exactly how high this cost could be. My paper, forthcoming in The Astronomical Journal, has predictions for what the night sky will look like if satellite companies follow through on their current plans. I also know that because of the geometry of sunlight and the orbits that have been chosen, 50 degrees north, where I live, will be the most severely affected part of the world.

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With no regulation, I know that in the near future, one out of every 15 points you can see in the sky will actually be relentlessly crawling satellites, not stars. This will be devastating to research astronomy, and will completely change the night sky worldwide.

The future is too, too bright

In order to find out how badly the night sky is going to be affected by sunlight reflected from planned satellite megaconstellations, we built an open-source computer model to predict satellite brightnesses as seen from different places on Earth, at different times of night, in different seasons. We also built a simple web app based on this simulation.

Our model uses 65,000 satellites on the orbits filed by four megaconstellation companies: SpaceX Starlink and Amazon Kuiper (United States), OneWeb (United Kingdom) and StarNet/GW (China). We calibrated our simulation to match telescope measurements of Starlink satellites, since they are by far the most numerous.

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Starlink has so far made some strides toward dimming their satellites since their first launch, but most are still visible to the naked eye.

Our simulations show that from everywhere in the world, in every season, there will be dozens to hundreds of satellites visible for at least an hour before sunrise and after sunset. Right now, it’s relatively easy to escape urban light pollution for dark skies while camping or visiting your cabin, but our simulations show that you can’t escape this new satellite light pollution anywhere on Earth, even at the North Pole.

The most severely affected locations on Earth will be 50 degrees north and south, near cities like London, Amsterdam, Berlin, Prague, Kiev, Vancouver, Calgary and my own home. On the summer solstice, from these latitudes, there will be close to 200 satellites visible to the naked eye all night long.

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I study orbital dynamics of the Kuiper Belt, a belt of small bodies beyond Neptune. My research relies on long time-exposure, wide-field imaging to discover and track these small bodies to learn about the history of our Solar System.

The telescope observations that are key to learning about our universe are about to get much, much harder because of unregulated development of space.

Astronomers are creating some mitigation strategies, but they will require time and effort that should be paid for by megaconstellation companies.

Unknown environmental costs

Starlink internet might appear cheaper than other rural options, but this is because many costs are offloaded. One immediate cost is atmospheric pollution from the hundreds of rocket launches required to build and maintain this system.

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Every satellite deployment dumps spent rocket bodies and other debris into already-crowded low Earth orbit, increasing collision risks. Some of this space junk will eventually fall back to Earth, and those parts of the globe with the highest overhead satellite densities will also be the most likely to be literally impacted.

Starlink plans to replace each of the 42,000 satellites after five years of operation, which will require de-orbiting an average 25 satellites per day, about six tons of material. The mass of these satellites won’t go away — it will be deposited in the upper atmosphere. Because satellites comprise mostly aluminium alloys, they may form alumina particles as they vaporize in the upper atmosphere, potentially destroying ozone and causing global temperature changes.

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This has not yet been studied in-depth because low Earth orbit is not currently subject to any environmental regulations.

Regulating the sky

Currently, low Earth orbit, where all of these satellites are planned to operate, is almost completely unregulated. There are no rules about light pollution, atmospheric pollution from launches, atmospheric pollution from re-entry, or collisions between satellites.

These megaconstellations might not even be financially viable over the long term, and internet speeds may slow to a crawl when many users connect at the same time or when it rains.

But companies are launching satellites right now at a frenetic pace, and the damage they do to the night sky, the atmosphere and the safety of low Earth orbit will not be undone even if the operators go bankrupt.

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There’s no doubt that rural and remote internet users in many places have been left behind by internet infrastructure development. But there are many other options for internet delivery that will not result in such extreme costs.

We can’t accept the global loss of access to the night sky, which we’ve been able to see and connect with for as long as we’ve been human.

With co-operation instead of competition between satellite companies, we could have many fewer in orbit. By changing the design of satellites, they could be made much fainter, having less of an impact on the night sky. We shouldn’t have to make a choice between astronomy and the internet.

But without regulations requiring these changes, or strong pressure from consumers indicating the importance of the night sky, our view of the stars will soon be changed forever.

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Samantha Lawler receives funding from the Natural Sciences and Engineering Research Council of Canada.

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This article is republished from The Conversation under a Creative Commons license. Disclosure information is available on the original site. Read the original article:

https://theconversation.com/soon-1-out-of-every-15-points-of-light-i https://theconversation.com/soon-1-o

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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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