Giant Puerto Rico radio telescope collapses, following damage

SAN JUAN, Puerto Rico—A huge, already damaged radio telescope in Puerto Rico that has played a key role in astronomical discoveries for more than half a century completely collapsed on Tuesday.

The telescope’s 900-ton receiver platform fell onto the reflector dish more than 400 feet below.

The U.S. National Science Foundation had earlier announced that the Arecibo Observatory would be closed. An auxiliary cable snapped in August, causing a 100-foot gash on the 1,000-foot-wide (305-meter-wide) reflector dish and damaged the receiver platform that hung above it. Then a main cable broke in early November.

The collapse stunned many scientists who had relied on what was until recently the largest radio telescope in the world.

“It’s a huge loss,” said Carmen Pantoja, an astronomer and professor at the University of Puerto Rico who used the telescope for her doctorate. “It was a chapter of my life.”

Scientists worldwide had been petitioning U.S. officials and others to reverse the NSF’s decision to close the observatory. The NSF said at the time that it intended to eventually reopen the visitor center and restore operations at the observatory’s remaining assets, including its two LIDAR facilities used for upper atmospheric and ionospheric research, including analyzing cloud cover and precipitation data.

The telescope was built in the 1960s with money from the Defense Department amid a push to develop anti-ballistic missile defenses. It had endured hurricanes, tropical humidity and a recent string of earthquakes in its 57 years of operation.

The telescope has been used to track asteroids on a path to Earth, conduct research that led to a Nobel Prize and determine if a planet is potentially habitable. It also served as a training ground for graduate students and drew about 90,000 visitors a year.

“I am one of those students who visited it when young and got inspired,” said Abel Méndez, a physics and astrobiology professor at the University of Puerto Rico at Arecibo who has used the telescope for research. “The world without the observatory loses, but Puerto Rico loses even more.”

He last used the telescope on Aug. 6, just days before a socket holding the auxiliary cable that snapped failed in what experts believe could be a manufacturing error. The National Science Foundation, which owns the observatory that is managed by the University of Central Florida, said crews who evaluated the structure after the first incident determined that the remaining cables could handle the additional weight.

But on Nov. 6, another cable broke.

A spokesman for the observatory said there would be no immediate comment, and a spokeswoman for the University of Central Florida did not return requests for comment.

Scientists had used the telescope to study pulsars to detect gravitational waves as well as search for neutral hydrogen, which can reveal how certain cosmic structures are formed. About 250 scientists worldwide had been using the observatory when it closed in August, including Méndez, who was studying stars to detect habitable plantes.

“I’m trying to recover,” he said. “I am

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Biblical Goliath may not have been a giant

Goliath, the giant who was felled by King David in the Hebrew Bible, is described as having a jaw-dropping height. 

But that number may not have been a true physical measurement but rather a metaphor, drawn from the width of his hometown’s city wall, new research suggests. That doesn’t reveal whether other aspects of the story are true — for instance whether Goliath was a giant or whether his mismatched battle with David took place.

“We’re not trying to make a statement on the veracity of the story,” said Jeffrey Chadwick, Jerusalem Center Professor of Archaeology and Near Eastern Studies at Brigham Young University, in a paper he presented at the American Schools of Oriental Research (ASOR) virtual annual meeting on Nov 19. “The issue is the metric,” he said, “where does it come from, where might it have been obtained?”

Related: Biblical battles: 12 ancient wars lifted from the bible

Ancient metrics

The lower north city wall in the ancient city of Gath measured about 7.8 feet (2.38 meters) in width. This is equal to four cubits and a span — the same height that Goliath once stood according to some biblical texts. (Image credit: Aren Maeir, 2019)

Some ancient texts say that Goliath stood at “four cubits and a span” –- which Chadwick says equals about 7.80 feet (2.38 meters) — while other ancient texts claim that he towered at “six cubits and a span” — a measurement equivalent to about 11.35 feet (3.46 m). That would certainly have been an impressive height, as the tallest recorded person in modern times was Robert Wadlow, who stood an impressive 8 feet 11 inches (2.72 m) tall, according to Guinness World Records

But how much these “cubits” and “spans” are in modern-day measurements is a source of debate among scholars. These measurements probably varied throughout the ancient world. Chadwick has been studying ancient architectural sites throughout ancient Israel, measuring the remnants of numerous structures and noting measurements that seem to be used frequently. His research indicates that a “cubit” in the region was equal to 1.77 feet (54 centimeters), and a span was equal to 0.72 feet (22 cm). He is preparing his metrics research for publication. 

Hometown measurement

The site of Gath (also known as Tell es-Safi) is seen here from a distance. According to the Hebrew Bible, it was the hometown of Goliath. (Image credit: Jeff Chadwick)

Chadwick is part of a team that is excavating Gath (also known as Tell es-Safi), a Philistine city where Goliath grew up, according to the Hebrew Bible. 

Related: 7 biblical artifacts that will probably never be found

Recently, the team has excavated a fortification wall found in the northern part of the lower city. The wall was built in the 10th century B.C., a time “when the Philistines controlled the city as it served as their capital,” Chadwick told Live Science. “The stone wall foundations measured exactly 2.38 m — four cubits and a span — in width at

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Inside YouTuber Mark Rober’s workshop, rocket-powered golf clubs and a giant Nerf gun

Some people might call Mark Rober the world’s biggest kid.



Mark Rober wearing a hat: Mark Rober, a former NASA engineer, talks to "Nightline" about launching his YouTube career and the work he does to inspire kids now.


© ABC News
Mark Rober, a former NASA engineer, talks to “Nightline” about launching his YouTube career and the work he does to inspire kids now.

The former NASA engineer turned YouTube sensation has amassed 15 million subscribers through videos of larger than life science experiments, like building the world’s largest Nerf gun or a bowling ball that only makes strikes.

Rober says he makes these videos because he’s “passionate” about getting people “just stoked” about science and engineering.

“That’s kind of my M.O. Like, all of my videos essentially drive back to that point,” Rober said. “So I’ll suck people in with something big, like, world’s largest Nerf gun, world’s largest Super Soaker, but at the end of the day, it’s about telling them about the science of what’s going on there.”



a man sitting on a motorcycle: YouTuber Mark Rober, a former NASA engineer, shows "Nightline's" Ashan Singh a giant Nerf gun that he'd built.


© ABC News
YouTuber Mark Rober, a former NASA engineer, shows “Nightline’s” Ashan Singh a giant Nerf gun that he’d built.

“Nightline” caught up with Rober last year, before the coronavirus pandemic began. But while much of the world stopped, Rober, who has been making videos for nine years, continued experimenting. The scientist even documented his isolation following a positive COVID-19 test in a Shark Week video.

Rober says he discovered his gift for physics, chemistry and math at a young age.

“High school physics was a big deal for me,” he said. “That’s when it finally clicked for me that you could just explain the world around you… And so, a lot of my videos come down to physics principles. I’m trying to explain to people, like, ‘This world is magical but magical in a way that if you understand how it works, you can predict the future and you can make cooler things.”



Mark Rober wearing a hat: Mark Rober, a former NASA engineer, talks to "Nightline" about launching his YouTube career and the work he does to inspire kids now.


© ABC News
Mark Rober, a former NASA engineer, talks to “Nightline” about launching his YouTube career and the work he does to inspire kids now.

Rober spent nine years at NASA, working in its jet propulsion lab. For seven of those years, he worked on the Curiosity rover, which was sent to Mars in 2011. He said that every so often, he’ll sit in his backyard and look up at the sky at a “little dot” that is Mars.

“To know that something I’ve touched and designed and tested is roving on that little dot in the sky, 90 million miles away, it’s a cool feeling,” he said.



Mark Rober et al. taking a selfie: YouTuber Mark Rober and "Nightline's" Ashan Singh inside Rober's San Franscisco Bay Area workshop, where Rober shows Singh a version of a glitter bomb he used to prank a package thief.


© ABC News
YouTuber Mark Rober and “Nightline’s” Ashan Singh inside Rober’s San Franscisco Bay Area workshop, where Rober shows Singh a version of a glitter bomb he used to prank a package thief.


MORE: NASA skims surface of asteroid to collect sample

It was while Rober was working for NASA that he produced his first video, in which he demonstrated a Halloween costume that used two iPads to make it seem as if he’d had a hole blown through his torso. The video racked up nearly 10 million views.

“That was a

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Losing Arecibo’s giant dish leaves humans more vulnerable to space rocks, scientists say

Ignorance may feel like bliss, but preparedness offers better odds of surviving what is to come. And when it comes to planetary defense, ignorance just became a bit more inevitable.

Planetary defense is the art of identifying and mitigating threats to Earth from asteroid impacts. And among its tools is planetary radar, an unusual capability that can give scientists a much better look at a nearby object. Arecibo Observatory in Puerto Rico was one of only a couple such systems on the planet, and that instrument’s long tenure is over now after two failed cables made the telescope so unstable that there was no way to even evaluate its status without risking workers’ lives, according to the U.S. National Science Foundation (NSF), which owns the site. Instead, it will be decommissioned.

And when it comes to planetary defense, there’s nothing like it.

“There’s been statements in the media that, ‘Oh we have other systems that can kind of replace what Arecibo is doing,’ and I don’t think that’s true,” Anne Virkki, who leads the planetary radar team at Arecibo Observatory, told Space.com. “It’s not obsolete and it’s not easily replaceable by other existing facilities and instruments.”

Related: Losing Arecibo Observatory would create a hole that can’t be filled, scientists say

Planetary defense begins with spotting as many near-Earth asteroids as possible — nearly 25,000 to date, according to NASA — and estimating their sizes and their orbits around the sun. Arecibo never played a role in discovering asteroids; that task is much more easily completed by a host of telescopes that see large swaths of the sky in visible and infrared light and are able to catch the sudden appearance of a bright, fast-moving dot between the stars, telescopes like the PanSTARRS observatory in Hawaii. With those first observations, the smallest asteroids and those that stay far from Earth can be safely labeled and more or less forgotten.

But larger asteroids with orbits that might bring them too close for comfort get additional study, and often, that work has been Arecibo Observatory’s. The facility sported a powerful radar transmitter that could bounce a beam of light off an object in Earth’s neighborhood. Then, the observatory’s massive radio dish could catch the echo of that signal, letting scientists decipher precise details about an asteroid’s location, size, shape and surface.

The same telescopes that identify asteroids in the first place can also give scientists the data they need to track a space rock’s orbit, but when planetary radar can spot the object, it completes the same work more quickly.

Sometimes that speed will matter, said Bruce Betts, chief scientist at the Planetary Society, a nonprofit space-exploration advocacy group that includes planetary defense among its key issues. “You want to define an orbit as quickly as you can to figure out whether the asteroid is going to hit Earth,” Betts told Space.com.

That’s because with enough warning, humans could theoretically do something to prevent the collision — likely by nudging

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European Space Agency is sending a giant claw into orbit to clean up space junk

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The Claaaaaaaaaaaaawwww…


ClearSpace

There are roughly 2,800 live satellites currently orbiting Earth. That’s a lot, but it’s absolutely nothing compared to the amount of defunct objects — AKA space junk — also circling the globe

Scientists estimate that almost 3,000 dead satellites are currently orbiting our planet, which doesn’t account for the 900,000 pieces of debris, less than 10 centimetres long, that could potentially cause a catastrophe should it hit the wrong satellite at the wrong time. 

Scientists and engineers are currently hard at work trying to solve the problem, but the European Space Agency is currently in the beginning stages of executing one of the more bizarre solutions: A space claw that will grip larger defunct satellites and steer them back into the earth’s atmosphere where both the satellite and the claw itself can burn up in peace.

The plan was initially conceived back in 2019, but now the ESA is officially signing a contract with Swiss start-up ClearSpace SA to build and launch its very first debris removal mission, called ClearSpace-1. 

The claw’s first target is a VESPA (Vega Secondary Payload Adapter) that’s been orbiting Earth since it helped launch an ESA Vega rocket back in 2013. The VESPA weighs 112 kgs and, according to the ESA, is close in size to a small satellite. 

The ESA is contributing €86 million to the cost of the mission. It’s expected that ClearSpace will raise the rest as it attempts to make a long term business of junk removal. Hopefully this mission can become the first of many, as humanity discovers new and innovative ways to clean up the gargantuan mess it’s made of the space above our atmosphere.

ClearSpace SA is hoping to launch its first mission in 2025.

Long live the claw.

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The biblical warrior Goliath may not have been so giant after all

Early versions of the Bible describe Goliath — an ancient Philistine warrior best known as the loser of a fight with the future King David — as a giant whose height in ancient terms reached four cubits and a span. But don’t take that measurement literally, new research suggests.

Archaeological findings at biblical-era sites including Goliath’s home city, a prominent Philistine settlement called Gath, indicate that those ancient measurements work out to 2.38 meters, or 7 feet, 10 inches. That’s equal to the width of walls forming a gateway into Gath that were unearthed in 2019, according to archaeologist Jeffrey Chadwick of Brigham Young University in Provo, Utah.

Rather than standing taller than any NBA player ever, Goliath was probably described metaphorically by an Old Testament writer as a warrior who matched the size and strength of Gath’s defensive barrier, Chadwick said November 19 at the virtual annual meeting of the American Schools of Oriental Research.

People known as Canaanites first occupied Gath in the early Bronze Age, roughly 4,700 to 4,500 years ago. The city was rebuilt more than a millennium later by the Philistines, known from the Old Testament as enemies of the Israelites (SN: 11/22/16). Gath reached its peak during the Iron Age around 3,000 years ago, the time of biblical references to Goliath. Scholars continue to debate whether David and Goliath were real people who met in battle around that time.

The remains of Gath are found at a site called Tell es-Safi in Israel. A team led by archaeologist Aren Maeir of Bar-Ilan University in Ramat-Gan, Israel — who Chadwick collaborated with to excavate the Gath gateway — has investigated Tell es-Safi since 1996. Other discoveries at Gath include a pottery fragment inscribed with two names possibly related to the name Goliath. Evidence of Gath’s destruction about 2,850 years ago by an invading army has also been recovered.

Iron Age gateway at et-Tell
Each of four inner pillars of an Iron Age gateway at et-Tell (possibly the biblical city of Bethsaida), including this one, measures 2.38 meters, or four cubits and a span, wide. That’s the same width as walls at Goliath’s home city, Gath, and the same height that an Old Testament writer used to describe Goliath.Eric Welch

Archaeologists have long known that in ancient Egypt a cubit corresponded to 52.5 centimeters and assumed that the same measure was used at Gath and elsewhere in and around ancient Israel. But careful evaluations of many excavated structures over the last several years have revealed that standard measures differed slightly between the two regions, Chadwick said.

Buildings at Gath and several dozen other cities from ancient Israel and nearby kingdoms of Judah and Philistia, excavated by other teams, were constructed based on three primary measurements, Chadwick has found. Those include a 54-centimeter cubit (versus the 52.5-centimeter Egyptian cubit), a 38-centimeter short cubit and a 22-centimeter span that corresponds to the distance across an adult’s outstretched hand.

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Giant ‘toothed’ birds flew over Antarctica 40 million to 50 million years ago

Picture Antarctica today and what comes to mind? Large ice floes bobbing in the Southern Ocean? Maybe a remote outpost populated with scientists from around the world? Or perhaps colonies of penguins puttering amid vast open tracts of snow?

Fossils from Seymour Island, just off the Antarctic Peninsula, are painting a very different picture of what Antarctica looked like 40 to 50 million years ago – a time when the ecosystem was lusher and more diverse. Fossils of frogs and plants such as ferns and conifers indicate Seymour Island was much warmer and less icy, while fossil remains from marsupials and distant relatives of armadillos and anteaters hint at the previous connections between Antarctica and other continents in the Southern Hemisphere.

There were also birds. Penguins were present then, as they are now, but fossil relatives of ducks, falcons and albatrosses have also been found in Antarctica. My colleagues and I have recently published an article revealing new information about the fossil group that would have dwarfed all the other birds on Seymour Island: the pelagornithids, or “bony-toothed” birds.

Giants of the sky

As their name suggests, these ancient birds had sharp, bony spikes protruding from sawlike jaws. Resembling teeth, these spikes would have helped them catch squid or fish. We also studied another remarkable feature of the pelagornithids – their imposing size.

The largest flying bird alive today is the wandering albatross, which has a wingspan that reaches 11 ½ feet. The Antarctic pelagornithids fossils we studied have a wingspan nearly double that – about 21 feet across. If you tipped a two-story building on its side, that’s about 20 feet.

Across Earth’s history, very few groups of vertebrates have achieved powered flight – and only two reached truly giant sizes: birds and a group of reptiles called pterosaurs.

A model of an enormous prehistoric bird is mounted outdoor in the middle of a river. The wingspan reaches from bank to bank.
A model of an enormous prehistoric bird is mounted outdoor in the middle of a river. The wingspan reaches from bank to bank.

Pterosaurs ruled the skies during the Mesozoic Era (252 million to 66 million years ago), the same period that dinosaurs roamed the planet, and they reached hard-to-believe dimensions. Quetzalcoatlus stood 16 feet tall and had a colossal 33-foot wingspan.

Birds get their opportunity

Birds originated while dinosaurs and pterosaurs were still roaming the planet. But when an asteroid struck the Yucatan Peninsula 66 million years ago, dinosaurs and pterosaurs both perished. Some select birds survived, though. These survivors diversified into the thousands of bird species alive today. Pelagornithids evolved in the period right after dinosaur and pterosaur extinction, when competition for food was lessened.

The earliest pelagornithid remains, recovered from 62-million-year-old sediments in New Zealand, were about the size of modern gulls. The first giant pelagornithids, the ones in our study, took flight over Antarctica about 10 million years later, in a period called the Eocene Epoch (56 million to 33.9 million years ago). In addition to these specimens, fossilized remains from other pelagornithids have been found on every continent.

Pelagornithids lasted for about 60

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Antarctica yields oldest fossils of giant birds with 6.4-meter wingspans

Antarctica yields oldest fossils of giant birds with 21-foot wingspans
This five-inch segment of fossilized jaw, which was discovered in Antarctica in the 1980s, dates from 40 million years ago. The skull of the bird would have been about two feet long, while the pseudoteeth, which were originally covered with horny keratin, would have been up to an inch long. At this scale, the bird’s wingspan would have been 5 to 6 meters, or some 20 feet. Credit: UC Berkeley image by Peter Kloess

Fossils recovered from Antarctica in the 1980s represent the oldest giant members of an extinct group of birds that patrolled the southern oceans with wingspans of up to 21 feet (6.4 meters) that would dwarf the 11½-foot wingspan of today’s largest bird, the wandering albatross.


Called pelagornithids, the birds filled a niche much like that of today’s albatrosses and traveled widely over Earth’s oceans for at least 60 million years. Though a much smaller pelagornithid fossil dates from 62 million years ago, one of the newly described fossils—a 50 million-year-old portion of a bird’s foot—shows that the larger pelagornithids arose just after life rebounded from the mass extinction 65 million years ago, when the relatives of birds, the dinosaurs, went extinct. A second pelagornithid fossil, part of a jaw bone, dates from about 40 million years ago.

“Our fossil discovery, with its estimate of a 5-to-6-meter wingspan—nearly 20 feet—shows that birds evolved to a truly gigantic size relatively quickly after the extinction of the dinosaurs and ruled over the oceans for millions of years,” said Peter Kloess, a graduate student at the University of California, Berkeley.

The last known pelagornithid is from 2.5 million years ago, a time of changing climate as Earth cooled, and the ice ages began.

Kloess is the lead author of a paper describing the fossil that appears this week in the open access journal Scientific Reports. His co-authors are Ashley Poust of the San Diego Natural History Museum and Thomas Stidham of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences in Beijing. Both Poust and Stidham received their Ph.Ds from UC Berkeley.

Birds with pseudoteeth

Pelagornithids are known as ‘bony-toothed’ birds because of the bony projections, or struts, on their jaws that resemble sharp-pointed teeth, though they are not true teeth, like those of humans and other mammals. The bony protrusions were covered by a horny material, keratin, which is like our fingernails. Called pseudoteeth, the struts helped the birds snag squid and fish from the sea as they soared for perhaps weeks at a time over much of Earth’s oceans.

Large flying animals have periodically appeared on Earth, starting with the pterosaurs that flapped their leathery wings during the dinosaur era and reached wingspans of 33 feet. The pelagornithids came along to claim the wingspan record in the Cenozoic, after the mass extinction, and lived until about 2.5 million years ago. Around that same time, teratorns, now extinct, ruled the skies.

The birds, related to vultures, “evolved wingspans close to what we see in

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Lucas Braathen earns first career World Cup win in giant slalom

SOELDEN, Austria — Lucas Braathen upset the favorites to clinch his first career win at the season-opening men’s World Cup giant slalom Sunday.

The Norwegian was fifth before posting the second fastest time in the decisive leg to finish ahead of Swiss duo Marco Odermatt and Gino Caviezel.

“It’s a pretty good day,” the 20-year-old Braathen told Austrian TV with a bright smile. “… I knew that I was capable of a podium. First victory, first race of the season, it’s unbelievable.”

Competing in only his 23th event in the World Cup, Braathen had a fourth place as his previous best result at the slalom in Kitzbuehel in January.

“I went for it. I am not here for fifth places, I am here for podiums,” Braathen said of his attacking second run.

Odermatt, the fastest racer in the second run, was 0.05 seconds behind, and Caviezel, who led after the opening run, trailed by 0.46 seconds.

Last year’s winner Alexis Pinturault missed the podium by 0.03 seconds in fourth, while GS world champion Henrik Kristoffersen finished in joint fifth place with Loic Meillard, the third Swiss skier in the top five.

Defending overall World Cup champion Aleksander Aamodt Kilde failed to finish his first run. Braathen’s Norwegian teammate came wide on a left turn and lost his right ski when he caught a bump.

Ted Ligety, who won the race a record four times, was 10th after the opening run but the American’s left ski came off early in his second.

The GS has become a wide-open discipline since the retirement of Marcel Hirscher. The dominant Austrian won the GS season title six times in seven years before ending his career in 2019.

Last season, Kristoffersen scooped the title, but Pinturault, Croatia’s Filip Zubcic and Slovenia’s Zan Kranjec all finished within 30 points of the Norwegian’s tally after seven races.

The Russian team was excluded from Sunday’s race after coronavirus tests of two of its coaches came back with unclear results.

The team, including racers Pavel Trikhichev, Alexander Andrienko and Ivan Kuznetsov, was isolated awaiting results of retests.

No spectators were allowed at the race as one of the precautionary health and safety measures amid the pandemic.

The next World Cup races are parallel events for men and women in another Austrian resort, Lech/Zuers, on Nov. 13-14.

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Laser technology used to measure biomass of giant Californian redwood trees

Oct. 15 (UPI) — For the first time, researchers have executed a three-dimensional survey of the world’s biggest trees, using laser technology to precisely measure the volume and biomass of Northern Californian redwoods.

Researchers detailed the feat in a new paper published Thursday in the journal Scientific Reports.

California’s giant redwood trees play an outsized role in above ground carbon sequestration, and have a larger impact on their ecosystems than their more diminutive neighbors.

“They are also very hard to measure and so tend to be underrepresented in measurements and models of above ground biomass,” Mat Disney, professor of geography at University College London, said in a news release.

Researchers used ground-based lasers to measure the biomass of large coastal redwood trees, Sequoia sempervirens, at three forest sites in Northern California. Scientists hope the data will help them more precisely monitor the impacts of climate change on redwood forests.

“Big questions within climate science in response to rising CO2 levels are whether and where more trees should be planted and how best to conserve existing forests,” said Disney, lead author of the new study. “In order to answer these questions, scientists first need to understand how much carbon is stored in different tree species.”

Traditional means for measuring tree biomass require either cutting and weighing trees piece by piece or by scaling up manual measurements — methods ripe for error.

The latest survey allowed scientists to chance to test the laser system that will be deployed on NASA’s GEDI mission, an effort to map forest carbon from space.

The colossal 1,400-year-old redwood known as the Colonel Armstrong tree was among the trees scanned by the GEDI lasers. The tree measures 288 feet tall, more than 11 feet wide and weighs 110 tons.

When researchers compared the laser-based biomass measurements with those made via 3D crown mapping, a more involved, fine-scaled measuring method involving expert climbers, they found the data agreed to within 2 percent.

Scientists suggest future tree survey could combine selective 3D crown mapping efforts with laser-based measurements.

“Estimating the biomass of large trees is critical to quantifying their importance to the carbon cycle, particularly in Earth’s most carbon rich forests,” said co-author and NASA scientist Laura Duncanson.

“This exciting proof of concept study demonstrates the potential for using this new technology on giant trees — our next step will be to extend this application to a global scale in the hopes of improving GEDI’s biomass estimates in carbon dense forests around the world,” said Duncanson, an assistant professor at the University of Maryland.

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