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Astronomers Are Increasingly Worried About How Satellite Megaconstellations Will Disrupt Science – Gizmodo

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A SpaceX Falcon 9 lifts off from Cape Canaveral in Florida carrying 60 Starlink satellites, January 6, 2020.
Image: SpaceX

Organizers of an American Astronomical Society conference in Hawaii held a special session to discuss the ways in which satellite megaconstellations, such as the one currently being built by SpaceX, are poised to disrupt telescopic observations. The astronomers also proposed potential solutions to this emerging problem.

The special session, titled “Challenges to Astronomy from Satellites,” was held yesterday at the 235th Meeting of the American Astronomical Society (AAS) currently being held in Honolulu, Hawaii. The session, chaired by Connie Walker from the National Science Foundation’s Optical-Infrared Astronomy Research Laboratory in Tucson, Arizona, was prompted by recent developments relating to the construction of the SpaceX Starlink megaconstellation, but the point of the meeting was to discuss the prospect in general, as several other firms are planning to build substantial satellite constellations of their own.

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That Starlink was a focal point of the meeting barely registers as a surprise. SpaceX has now launched three batches of its small-sats, which places the total number at around 180. Each launch has been accompanied by a light show, in which an orderly procession of Starlink satellites have been seen zipping across the night sky. This train-like effect lasts for a week or more until the satellites disperse to their higher service orbits, but even then they are still visible to the naked eye. Perhaps unsurprisingly, Starlink trains have already disrupted astronomical observations.

That’s certainly one problem, but another has to do with the sheer volume of satellites expected to enter into orbit over the coming years. SpaceX ultimately wants its Starlink constellation to consist of tens of thousands of satellites, while other companies, such as OneWeb, Telsat, and Amazon, are hoping to build their own multi-satellite constellations. The private sector is set to increase the number of objects in space by an order of magnitude, and this unprecedented experiment—without any apparent thought to the consequences—could disrupt astronomical observations to an alarming degree.

Jonathan McDowell, an astronomer at Harvard-Smithsonian Center for Astrophysics and an expert on satellites, attended this special AAS session and talked to his peers about the subject. He also met with SpaceX reps.

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“I do believe SpaceX is making a good-faith effort to fix the problem,” McDowell told Gizmodo in an email. “I think they can get the satellites fainter than what the naked eye can see, which is a minimal thing to not spoil the night sky for non-astronomers.”

As for professional astronomers, he fears there will be times of the year when these satellites will pose “at minimum a big problem,” saying he worries there will be issues astronomers have not even thought of yet.

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During yesterday’s session, Patricia Cooper, the vice president of satellite government affairs for SpaceX, said the “level of brightness and visibility was a surprise to us,” reported SpaceNews.

This unexpected luminosity, said Cooper, is a consequence of the satellites having to be deposited in a low orbit as well as the way in which their large solar arrays are initially oriented. Once in their intended orbits, some 550 kilometers (342 miles) above Earth, their brightness is vastly diminished, but they can still be seen from the ground.

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SpaceX has responded to this problem. For the most recent deployment—in which SpaceX became the largest commercial satellite operator in the world—one Starlink satellite was treated with a special dark coating intended to diminish its reflectivity. We won’t know if this solution will work until February, when the satellites go into service.

In addition, the private space company is making the coordinates of each Starlink satellite available to astronomers, who can use this information when planning their observations, according to the Washington Post.

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“We don’t know yet if these mitigations are useful and effective,” said Cooper. “We tend to work very quickly. We tend to test, learn and iterate.”

The session also addressed megaconstellations in general, discussing the ways in which these satellite arrays could influence scientific observations, whether these satellites are used for telecommunications, as is the case for Starlink, or sweeping surveys of the Earth’s surface, such as the proposed ICEYE constellation, which would involve fleets of satellites equipped with synthetic-aperture radar (SAR).

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Speaking at the session, astronomer Patrick Seitzer from the University of Michigan warned of the deleterious effects, such as multiple streaks on images, ghost-like artifacts, the saturation of detectors with light, and interference with electronic devices, the BBC reported.

“Mega-constellations in Low Earth Orbit are coming and they are coming fast,” Seitzer was quoted as saying in the BBC. “The new satellites are brighter than 99% of objects in orbit,” adding that the initial batch of Starlink sats is “just the start.”

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Seitzer recommended that SpaceX make it so that its Starlink satellites are not visible to the naked eye even when in their service orbits and that the company work to reduce the brightness of these objects to prevent the over-saturation of large professional telescopes, the BCC reported. Upsettingly, he said the Vera C. Rubin Observatory, previously known as the Large Synoptic Survey Telescope, will be badly affected by megaconstellations, as this observatory, with its highly sensitive equipment, will map the entire sky once every three days.

Another problem mentioned at the conference is the threat of excessive radio interference coming from some of these satellites, such as the aforementioned ICEYE. Speaking to reporters at the conference, Harvey Liszt from the National Radio Astronomy Observatory (NRAO), said if SAR is pointed at a radio telescope that’s looking directly back at it, SAR “will burn out the radio astronomy receiver,” reported the BBC.

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Hopefully these discussions will further compel the private sector to adopt sensible practices prior to lobbing their products into space. It’s deeply disappointing that we’re having these conversations so late into the game. Being able to predict that tens of thousands—or possibly even hundreds of thousands—of satellites in low Earth orbit will affect our view of the cosmos isn’t exactly rocket science.

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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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