adplus-dvertising
Connect with us

Science

Space debris: 'Grandfather satellite' due to fall to Earth – Yahoo News Canada

Published

 on


Artwork: Europe’s Earth Remote Sensing satellites weighed about 2.5 tonnes at launch

A pioneering European satellite is due to fall to Earth in the coming hours.

ERS-2 was a cutting-edge observation platform when it launched in 1995, forging technologies that are now used routinely to monitor the planet.

It’s been gradually descending since ending operations in 2011 and will take an uncontrolled, fiery plunge into the atmosphere some time on Wednesday.

The European Space Agency (Esa) says most of the two-tonne satellite will burn up on the way down.

It’s possible some more robust parts may withstand the intense heating generated during the high-speed dive, but the chances of these fragments hitting populated areas and causing damage are slim.

They could land almost anywhere in the world but with most of the Earth’s surface covered by ocean, whatever debris survives to the surface is most likely to be lost at sea.

“And it’s worth highlighting that none of the elements that might re-enter the atmosphere (and reach the surface) are radioactive or toxic,” said Mirko Albani from Esa’s Earth Observation Ground Segment Department.

Sea-surface temperatureSea-surface temperature

Sea-surface temperature: Today’s climate monitoring owes a debt to the ERS programme

The agency launched two near-identical Earth Remote Sensing (ERS) satellites in the 1990s. They were the most sophisticated planetary observers of their day, carrying a suite of instruments to track changes on the land, in the oceans and in the air.

They monitored floods, measured continental and ocean-surface temperatures, traced the movement of ice fields, and sensed the ground buckle during earthquakes.

And ERS-2, specifically, introduced a new ability to assess Earth’s protective ozone layer.

The pair have been described as the “grandfathers of Earth observation in Europe”.

“Absolutely,” said Dr Ralph Cordey. “In terms of technology, you can draw a direct line from ERS all the way through to Europe’s Copernicus/Sentinel satellites that monitor the planet today. ERS is where it all started,” the Airbus Earth observation business development manager told BBC News.

Dr Ruth Mottram is a glaciologist with Danish Meteorological Institute. She recalled the revolution ERS brought to her discipline.

“When I was a university student in the 90s, we were told that the ice sheets were very cold and stable, and they weren’t going to change much; it would take decades before we saw any of the kinds of changes we expected to see as a result of climate change. And ERS really showed that this wasn’t true, and that there were big changes happening already.”

ERS-2ERS-2

Germany’s Dornier company (now Airbus) led the assembly of the ERS satellites

ERS-2 is the first of the duo to come home. Originally placed 780km above the Earth, engineers used its final fuel reserves in 2011 to lower its altitude to 570km. The expectation was that the upper atmosphere would then drag the spacecraft down to destruction in about 15 years.

This prediction will hold true on Wednesday afternoon, GMT.

Precisely when and where is difficult to say. Much will depend on the density of the upper atmosphere, something which is influenced by solar activity.

What can be said with certainty is that the re-entry will occur between 82 degrees North and South, as this was the extent of the satellite’s orbit around the Earth.

Esa’s space debris experts calculate little of ERS-2’s mass will endure to the Earth’s surface.

ERS-2 pictured about 250km above the EarthERS-2 pictured about 250km above the Earth

Australian tracking company HEO is following the descent of ERS-2

Those fragments that do impact the planet might include internal panelling and some metal parts, such as fuel and pressure tanks.

The element with potentially the highest probability of making it through the atmosphere in some form is the antenna for the synthetic aperture radar system, which was built in the UK. The antenna has a carbon-fibre construction that can tolerate high temperatures.

When ERS-2 was launched, the space debris mitigation guidelines were much more relaxed. Bringing home a redundant spacecraft within 25 years of end of operations was deemed acceptable.

Esa’s new Zero Debris Charter recommends the disposal grace period now not exceed five years. And its future satellites will be launched with the necessary fuel and capability to propulsively de-orbit themselves in short order.

The rationale is obvious: with so many satellites now being launched to orbit, the potential for collisions is increasing. ERS-1 failed suddenly before engineers could lower its altitude. It is still more than 700km above the Earth. At that height it could be 100 years before it naturally falls down.

Radar interferogramRadar interferogram

California’s Hayward fault: ERS pioneered radar interferometry and the mapping of rock movement

The American company SpaceX, which operates most of the functional satellites currently in orbit (more than 5,400), recently announced it would be bringing down 100 of them after discovering a fault that “could increase the probability of failure in the future”. It wants to remove the spacecraft before any problems make the task more difficult.

Last week, the Secure World Foundation, an advocacy group for the sustainable use of space, and LeoLabs, a US company that tracks space debris, issued a pressing statement on the need to remove redundant orbital hardware.

They said: “The accumulation of massive derelict objects in low Earth orbit continues unabated; 28% of the current long-lived massive derelicts were left in orbit since the turn of the century.

“These clusters of uncontrollable mass pose the greatest debris-generating potential to the thousands of newly deployed satellites that are fuelling the global space economy.”

Adblock test (Why?)

728x90x4

Source link

Continue Reading

News

Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

Published

 on

 

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. ”

___

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

___

Follow Seth Borenstein on Twitter at @borenbears

___

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.

Source link

Continue Reading

Science

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

Published

 on

 

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.

Source link

Continue Reading

News

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

Published

 on

 

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.

Source link

Continue Reading

Trending