Seven astronauts aboard the International Space Station woke to unwelcome news on the morning of November 15, 2021. NASA, the U.S. space agency, was worried. The station was zooming directly into a suddenly dangerous area littered with trash. A collision could damage the spacecraft. And that could threaten the safety of everyone inside. NASA warned the astronauts to take cover.
The astronauts closed hatches between sections of the ISS and climbed into escape ships. Then they waited. Fortunately, they transited the area without a mishap. All clear.
Soon, the source of all that debris would be revealed. Earlier that day, the Russian government had launched a rocket to blow up a big satellite. The satellite hadn’t worked since the 1980s. This launch was testing a new missile technology.
While the missile did its job, the explosion created a “debris field.” The shattered satellite showered space with some 1,500 pieces of trash big enough to see and track by telescope. It also produced hundreds of thousands of smaller pieces. Even a small piece could have ripped a hole through the exterior of the ISS. And the threat from this one satellite may persist for years, if not decades.
Space junk races around the planet at up to 8 kilometers (5 miles) per second. The speed of an impact can reach 15 kilometers per second, or 10 times as fast as a bullet. NASA scientists estimate that a marble-sized piece could smash into another object with as much force as a bowling ball traveling at 483 kilometers (300 miles) per hour.
The ISS passes through the same spot every 93 minutes as it circles the planet. On that mid-November day, everyone aboard feared an impact. But this wasn’t the first or last time space junk had threatened a mission. The explosion prompted NASA to cancel a planned, November 30 spacewalk. The Chinese space station, with three astronauts on board, had to change course because of the Russian satellite. Just three days before the explosion, the ISS changed its orbit to avoid colliding with space junk left by an older, broken-down satellite. And on December 3, the ISS again changed course to avoid pieces from a different broken-down satellite.
Space junk is a growing menace. Indeed, this trash “is now the number one concern of people who study space-traffic management,” says Pat Seitzer. He’s an astronomer at the University of Michigan, in Ann Arbor. He uses telescopes and computers to study orbital debris.
“We created this risk ourselves,” says Don Pollacco. Fortunately, he adds, “there’s stuff we can do to stop it from being a risk.” An astronomer at the University of Warwick in England, Pollacco runs the new Center for Space Domain Awareness. Scientists there focus on the environment in outer space that’s closest to Earth. The debris problem, he warns, threatens the future of space traffic.
“If you don’t deal with it, sooner or later it will catch up,” he says. “You can’t ignore it forever.”
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In this video, the European Space Agency outlines the problem of space debris and how it and other space agencies are tackling the problem.
Tracking the trash
The European Space Agency, or ESA, estimates that about 36,500 pieces of debris larger than 10 centimeters (4 inches) now orbit Earth. There are about a million pieces between 1 and 10 centimeters in diameter. More than 300 million pieces still smaller litter near space, too. Scientists use radar to track the biggest pieces. The smallest? They’re too small to measure precisely.
Soviets launched the first satellite into space — Sputnik I — on October 4, 1957. Since then, governments, militaries and companies around the world have sent up tens of thousands more. In 2020 alone, more than 1,200 new satellites entered space — more than any previous year. Of more than 12,000 satellites sent into space, the ESA estimates that about 7,630 are still in orbit. Only about 4,800 still work.
Space debris has been growing for decades. Most of it resides in what scientists call a low-Earth orbit, or LEO. That means it orbits about 1,000 kilometers (620 miles) above Earth’s surface. The ISS is also in low-Earth orbit.
From 1984 to 1990, the Long Duration Exposure Facility (at top) monitored small pieces of debris in Low-Earth Orbit, or LEO. NASA/Lockheed Martin/IMAX
Space debris includes big objects, such as pieces of rockets used to lift satellites into space. It also includes things such as nose cones and payload covers from those rockets. Then there are satellites that don’t work anymore — or failed from the start.
One is Envisat, a satellite ESA launched in 2002. It died 10 years into its mission of monitoring Earth’s climate. Its carcass will likely remain a threat for at least the next 100 years.
“It’s a big car crash in the sky just waiting to happen,” worries Pollacco.
A few big smashups have produced much of the known space debris. In 2007, China launched a missile to blow up one of its old weather satellites. The blast produced more than 3,500 pieces of large debris, as well as giant clouds of small pieces. In 2009, a defunct Russian satellite collided with a communications satellite owned by a U.S. company. This smashup also produced large clouds of debris.
The U.S. Department of Defense runs a Space Surveillance Network. It uses radar and other telescopes to track larger pieces of debris. This network now tracks more than 25,000 big chunks, according to NASA. When the chance that one of those chunks will collide with the ISS is greater than 1 in 10,000, the space station will move out of the way. Private companies have also started tracking debris in recent years.
Space trash can be quite diverse
In 1965, astronaut Ed White lost a glove during a spacewalk. Other astronauts have lost screwdrivers and other tools. Pieces of exploded batteries or fuel tanks — some with fuel still in them — are whizzing in orbit. So are flecks of peeled paint, nuts and bolts. At the speed they’re moving, all are dangerous.
A meteoroid or piece of debris smashed into the airlock shield of the ISS and left this crater behind. NASA
Scientists can’t see pieces of debris as small as bolts, nuts and paint flecks. Instead, they study the scratches and dents these leave behind on existing satellites. During an inspection in May 2021, astronauts found that a robotic arm of the ISS had been damaged by space debris. The arm still works, but it has a hole about 0.5 centimeter (0.2 inch) across.
The Hubble Space Telescope has provided a wealth of data from similar encounters with debris. Astronauts have visited and repaired the telescope multiple times in the last three decades. Each time they have found hundreds of tiny craters in the solar panels. These were left by collisions with small pieces of debris. Scientists have been logging the pattern and incidence of these impacts. That data will help the scientists build computer models that predict not only how many tiny pieces remain in orbit, but also where they are.
Studies of space debris confirm the threat is growing, says Seitzer, in Michigan. “It’s a real problem.” But he worries that people aren’t learning the right lessons. After the 2007 event in which China blew up a satellite and created a giant debris field, he thought people would work hard on the space-trash problem. “I would have thought everybody would be convinced.”
But they weren’t. So the problem continues to grow.
This video shows a lab experiment that simulates the impact of a small piece of orbital debris on an aluminum panel. NASA
The private company SpaceX has launched “constellations” of dozens of satellites. The company is using this project, called Starlink, to create a global internet system. Already, about 40 percent of active satellites in space belong to SpaceX. The company plans to launch thousands more. And they’re not alone. OneWeb, a communications company, has announced plans to launch its own constellation of 300,000 satellites.
When a company learns that its satellite is going to fly within 1 kilometer (0.6 mile) of another — or close to a piece of space junk — it can redirect its satellite a bit. In August, researchers in the United Kingdom reported that SpaceX Spacelink satellites have been involved in about half of all collision-avoidance moves in LEO. In the near future, they predict that share could rise to nine in every 10.
As the number of satellites in the sky mushrooms, so will the threat from collisions with debris, says Pallacco. “It’s a cumulative thing,” he says. “The less we do about it, the worse it gets.”
Beware the cascades
Astronomers worry that as space litter grows, these fragments also will interfere with telescope observations. “If you get enough of these collisions, you could brighten the night sky,” says Connie Walker. She’s an astronomer at the National Science Foundation’s NOIR Lab, in Tucson, Ariz.
She is concerned that space debris and satellites could limit the scientific study of space. That junk could reflect so much light that it hides the light of distant stars. Right now, scientists are trying to determine how space debris and the future flood of satellite constellations might affect telescope observations. For sensitive observatories, Walker says, “we need a sky that’s pretty clear and not highly light-polluted.”
Another less obvious risk is one that experts call the “Kessler Syndrome.” In 1978, NASA astronomer Donald Kessler looked at data on space debris and made an ominous prediction. Eventually, he said, LEO would accumulate so much space junk that it could trigger a cascade. The fragments from one collision would cause other collisions, he projected. Debris from those collisions would then cause more. And more, and more. This became known as the Kessler Syndrome, or Kessler Effect.
“We’re not there yet,” says Seitzer. But unless private companies, military operations and spacefaring governments take the problem seriously, he says, such a cascade could happen. “Even if we add nothing else, more collisions of existing things in orbit will create more debris.”
This telescope on Ascension Island (in the Atlantic Ocean) tracks orbital debris at different altitudes. Sqn Ldr Greg Cooke/Royal Air Force
To the graveyard orbit!
Some experts worry that people won’t take the problem seriously until tragedy strikes.
“Most people haven’t had an issue with a satellite problem,” observes science historian Lisa Ruth Rand. She works at the California Institute of Technology in Pasadena. “If we were to lose a satellite that the defense uses, or if something falls from space, that’s when people get terrified. That’s when space junk is a problem.”
Yet make no mistake, she says, space debris is already an environmental hazard. And she’s not the first to point this out. NASA scientists have warned about the dangers of polluting near-Earth space since the 1960s.
There are also companies and scientists working on ideas for cleaning up the mess. But they will need different strategies depending on which part of space they’re cleaning, says Walker, the NSF astronomer in Tucson.
“The higher you go, the longer it takes” for a satellite to de-orbit, she explains. Big pieces in LEO could be redirected back toward the planet, to burn up in the atmosphere.
The Japanese company Astroscale has designed spacecraft that will magnetically “grab” space junk and drag it to a lower orbit, from where it would then fall and burn up in the atmosphere. The company launched a pair of the satellites into space to test the technology in March 2020.
“When it comes to orbital debris, there are a variety of approaches on how to handle these things,” says Tom McCarthy. He’s a robotics expert at Motiv Space Systems in Pasadena, Calif. McCarthy has been developing spacecraft that can fix and recycle old satellites. Such technology could help extend the working life of those satellites, he says.
Space junk farther out may require a different strategy. Big pieces in a geostationary orbit — about 36,000 kilometers (22,000 miles) up — could be sent to a “graveyard orbit.” They would be propelled an additional 300 kilometers (190 miles) away from Earth, where they would remain, far from where they could do any major damage.
“A satellite could dock or connect with a geostationary satellite and then take it to the disposal orbit and release it,” says McCarthy. That may already be happening. In late January 2022, a company called Exoanalytic Solutions, which monitors the space environment, reported a curious observation. A Chinese satellite flew close to a large, dead satellite and towed it away to a graveyard orbit.
Other experts say that plans for removing satellites from orbit need to be built into a craft’s design. That’s something Astroscale is doing. The company developed a magnetic docking station to bolt onto a satellite before launch. Later, when it needs repairs or removal, another vehicle can be sent up to collect it.
An international committee with members from space agencies around the world recommends that all new satellites have the ability to de-orbit themselves within 25 years. Some satellites are close enough to do that naturally. Others aren’t. Of the ones that are too high to de-orbit on their own, fewer than one in four can lower themselves out of orbit, according to a July 2019 ESA report.
Pollacco says satellite designers need to address the space-debris issue well before liftoff. But right now, he says, the operators of the satellites don’t see the problem. “It’s in everybody’s interest for this stuff to be cleaned up,” he says. “If it isn’t, it will become all of our problem.”
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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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.
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.”
