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NASA is slamming a spacecraft into an asteroid on Monday to test planetary defence – CBC.ca

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On Monday, in what seems like a scene out of a science fiction movie, NASA will slam a spacecraft into a distant asteroid to see whether it can nudge its orbit — all in an effort to test a way to protect Earth from any potential future threats.

The good news is that there’s no need to panic: The asteroid, which is part of a binary — or two-bodied — system, is not a threat to our planet, and there are no known ones that are headed our way for at least the next 100 years. However, space agencies like the U.S. National Aeronautics and Space Administration want to be prepared should there ever be a threat.

NASA’s Double Asteroid Redirection Test (DART) is testing a way in which a spacecraft may be able to nudge an asteroid on a collision course with Earth out of its orbit.

At 7:14 p.m. ET on Monday, the refrigerator-sized spacecraft will plunge itself into Dimorphos — a moonlet that orbits its larger companion, Didymos — at roughly 6.6 km/s.

The goal isn’t to knock Dimorphos out of orbit but rather to change its 12-hour orbit around Didymos by 10 minutes. This means that scientists will know within roughly 12 hours whether they were successful.

So why target a binary asteroid system rather than a single asteroid to see whether you can change its orbit around the sun?

This image of the light from asteroid Didymos and its orbiting moonlet, Dimorphos, is a composite of 243 images taken by the Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO) on July 27. (NASA JPL DART Navigation Team)

“A binary system was perfect for this test,” said Mallory DeCoster, a senior scientist at Johns Hopkins University’s Applied Physics Laboratory in Maryland and part of the DART Impact Modeling Working Group.

For one, the size of Dimorphos — about 164 metres across — is perfect to illustrate whether this would be an effective way of deflecting asteroids that pose a threat to Earth. Didymos is 780 metres across.

“But then the other piece is, if we were to impact a single asteroid, in order to characterize if we changed its orbit, we would have to wait until it completed its orbit around the sun, which could take many, many years.”

The other advantage is that the binary system is relatively close to us, astronomically speaking, at just 11 million kilometres away.

Shooting gallery

NASA’s Center for Near-Earth Object Studies says that more than 90 per cent of near-Earth objects (NEOs) bigger than one kilometre have already been discovered. But that doesn’t mean we’re out of the woods when it comes to Potentially Hazardous Asteroids (PHAs).

In 2013, the Chelyabinsk asteroid — which was roughly 20 metres in diameter— exploded over parts of Russia, injuring about 1,000 people and serving as a reminder of how even a small asteroid can be dangerous.

In February 2013, a meteorite contrail was seen over Chelyabinsk, Russia, a city close to the Ural Mountains located about 1,500 kilometres east of Moscow. The Chelyabinsk asteroid, which was roughly 20 metres in diameter, exploded over parts of Russia, injuring about 1,000 people. (Chelyabinsk.ru, Yekaterina Pustynnikova/The Associated Press)

Basically, Earth flies through a shooting gallery in space. There are small chunks of debris that burn up in our atmosphere as meteors; bigger ones, like Chelyabinsk; and then even bigger ones that can be catastrophic — all left over from the formation of our solar system.

That’s why space agencies like NASA and the European Space Agency have been trying to develop ways to deflect or nudge a PHA so that its orbit changes and poses no threat to Earth.

Mike Daly, a professor at York University’s Lassonde School of Engineering in Toronto and a co-investigator on DART, said one of the most popular concepts is deflecting asteroids before they become a real threat. But that means we need to have advance warning that one is headed our way.

“So the simplest method is the one that DART is doing, which is essentially to take a spacecraft at high speed and crash it into the asteroid and use that transfer of the energy from the spacecraft to the asteroid to move it along,” he said.

This infographic shows the potential effect of DART’s impact on the orbit of Dimorphos. (NASA/Johns Hopkins APL)

However, the science behind asteroid deflection in this manner is about more than just the combination of the spacecraft’s size and incredibly high speed, called a hypervelocity impact.

“In a hypervelocity impact, you induce this pressure wave into the target that causes a lot of new physics to happen,” Johns Hopkins University’s DeCoster said.

“So what will happen, or what we think will happen, is that the size of the spacecraft might actually not matter that much. It might actually be: How does the asteroid respond to this pressure wave that is induced due to the hypervelocity impact? And we think that it will likely spew out a lot of material in the form of ejecta. And this ejecta might actually have a major component for changing the orbit. So much ejecta might get spewed out that that piece might matter more than the incoming energy from the spacecraft in changing its orbit.”

The DART team hopes that an onboard camera, called DRACO, will show the close approach and then suddenly go black, which would be indicative of an impact.

This map shows the 38 telescopic facilities in space and around the globe that are expected to observe the Didymos asteroid system in support of DART’s global observation campaign after impact. Numerical figures in parentheses next to the telescope names indicate the telescope size. (NASA/Johns Hopkins APL/Nancy Chabot/Mike Halstad)

But there’s a straggler tagging along behind DART, by about three minutes: the Italian Space Agency’s Light Italian Cubesat for Imaging of Asteroids, or LICIACube. Its job is to photograph the impact, study the plume of ejecta and help determine the morphology of the asteroid, as they can be made of iron, rock or just rocky clumps held together by gravity.

As this is the first test of a form of planetary defence, scientists are eagerly anticipating not only the impact of the event itself but what they will learn from it and, most importantly, what this may mean for the future of protecting Earth in the future. Telescopes from around the world will be observing the event and collecting followup data.

“We’re really the first generation that can protect ourselves from these potentially catastrophic impacts,” York University’s Daly said. “And, you know, fortunately the really catastrophic ones don’t happen very often, but they could happen, and never before have we been able to change our fate. So I think it’s really up to us, given the potentially large consequences of not paying attention and our ability to do it.”

The event will be broadcast on NASA TV, which is available online and through its app.

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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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