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Asteroid 1998 OR2 to Safely Fly Past Earth This Week – Jet Propulsion Laboratory

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The large near-Earth object is well known to astronomers and will get no closer than 3.9 million miles to our planet.


A large near-Earth asteroid will safely pass by our planet
on Wednesday morning, providing astronomers with an exceptional opportunity to
study the 1.5-mile-wide (2-kilometer-wide) object in great detail.

The asteroid, called 1998 OR2, will make its closest
approach at 5:55 a.m. EDT (2:55 a.m. PDT). While this is known as a “close
approach” by astronomers, it’s still very far away: The asteroid will get
no closer than about 3.9 million miles (6.3 million kilometers), passing more
than 16 times farther away than the Moon.


This GIF, composed of observations by the Virtual Telescope Project, shows asteroid 1998 OR2 (the central dot) as it traversed the constellation Hydra five days before its closest approach to Earth. It was about 4.4 million miles (7.08 million kilometers) away from Earth at the time. Credit: Dr. Gianluca Masi (Virtual Telescope Project)

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Asteroid 1998 OR2 was discovered by the Near-Earth Asteroid
Tracking program at NASA’s Jet Propulsion Laboratory in July 1998, and for the
past two decades astronomers have tracked it. As a result, we understand its
orbital trajectory very precisely, and we can say with confidence that this
asteroid poses no possibility of impact for at least the next 200 years. Its
next close approach to Earth will occur in 2079, when it will pass by closer –
only about four times the lunar distance.

Despite this, 1998 OR2 is still categorized as a large
“potentially hazardous asteroid” because, over the course of
millennia, very slight changes in the asteroid’s orbit may cause it to present
more of a hazard to Earth than it does now. This is one of the reasons why
tracking this asteroid during its close approach – using telescopes and especially
ground-based radar – is important,
as observations such as these will enable an even better long-term assessment
of the hazard presented by this asteroid.

Close approaches by large asteroids like 1998 OR2 are quite
rare. The previous close approach by a large asteroid was made by asteroid
Florence in September 2017. That 3-mile-wide (5-kilometer-wide) object zoomed
past Earth at 18 lunar distances. On average, we expect asteroids of this size
to fly by our planet this close roughly once every five years.

Since they are bigger, asteroids of this size reflect much
more light than smaller asteroids and are therefore easier to detect with
telescopes. Almost all near-Earth asteroids (about 98%) of the size of 1998 OR2
or larger have already been discovered, tracked and cataloged. It is extremely
unlikely there could be an impact over the next century by one of these large
asteroids, but efforts to discover all asteroids that could pose an impact
hazard to Earth continue.

JPL hosts the Center for Near-Earth Object Studies (CNEOS)
for NASA’s Near-Earth Object Observations Program in NASA’s Planetary Defense
Coordination Office.

More information about CNEOS, asteroids and near-Earth
objects can be found at:

https://cneos.jpl.nasa.gov

For more information about NASA’s Planetary Defense
Coordination Office, visit:

https://www.nasa.gov/planetarydefense

For asteroid and comet news and updates, follow @AsteroidWatch
on Twitter:

https://twitter.com/AsteroidWatch

News Media Contact

Ian J. O’Neill
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-2649
ian.j.oneill@jpl.nasa.gov

Josh Handal
NASA Headquarters, Washington
202-358-2307
joshua.a.handal@nasa.gov

2020-081

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Fermenting ferns? Rare dinosaur stomach fossil opens door to ancient world – News Talk 650 CKOM

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Fresh ferns, loaded with spores, lightly dusted with leaves and twigs and perfectly seasoned with locally sourced charcoal.

Sound good? It did to an ankylosaur about 110 million years ago, as evidenced by amazingly complete fossils of what was certainly the tank-like dinosaur’s last meal.

“It’s pretty exciting,” said Caleb Brown, a curator at the Royal Tyrrell Museum of Paleontology and co-author of a paper published Tuesday on what is one of probably only three fossilized dinosaur stomachs discovered.

“We can start recontructing the life histories and ecologies of these animals.”

The dining dinosaur was first unearthed in 2011 in a northern Alberta Suncor oilsands mine, where many excavators have learned to look for fossils as they dig. When this one turned up, a crew from the Tyrrell followed shortly afterward.

It was an amazingly well-preserved ankylosaur from the early Cretaceous period. Low but large — the species could reach eight metres long and weigh eight tonnes — the fossil took two weeks to remove.

It then took 5 1/2 years for technician Mark Mitchell to clean and prepare it, which is why the species now bears the Latin name markmitchelli. The restored specimen, complete with body armour and outer skin, was remarkable enough for a 2017 National Geographic magazine feature.  

But for paleontologists, the fun was just starting. They began looking at a fossilized structure that co-author Jim Basinger of the University of Saskatchewan described as looking like a “squashed basketball.”

It was in the right place for a stomach and it held gastroliths, small stones dinosaurs used to help digest their food, much as some birds do today.

“There’s a great mess of them and they’re quite distinctive,” said Basinger.

The scientists eventually compiled 16 pieces of evidence that the squashed basketball was, in fact, a stomach.  

“It’s unquestionable,” Basinger said.

There are only two other fossilized stomachs in the world that scientists are this sure about. Neither opens doors to the past the way this one does.

About 80 per cent of this last meal was a particular species of ferns. The fossils are so well preserved their spores identify them.

There are bits of other plants and twigs so immaculate that their growth rings are being used to estimate weather at the time. And there is charcoal from burned woody material.

Brown points out ferns aren’t that nutritious. A beast this size would need digestion capable of getting the most from them.

That means this dinosaur may have fermented its food, much like many animals today.

“All big herbivores today use some form of fermentation,” Brown said. “For this animal, it was almost certainly fermenting those ferns.”

Which raises other interesting questions: How much fermented fern does it take to move an eight-tonne lizard? How much energy might it need? Where might that much fodder be found?

The charcoal provides a clue. It probably came from an ancient forest fire where ferns would have been abundant in the first flush of new growth, much as they are today.

“(The dinosaur) was taking advantage of a charred landscape,” Basinger said. Many modern animals do the same, chowing down on tender, nutritious and low-hanging new growth that follows the flames.

More than just reassembling skeletons, modern paleontology is starting to rebuild ecosystems that haven’t existed for millions and millions of years.

“That’s something we can start playing with,” Brown said. 

The fossils tell individual stories, too.

Basinger said, given the undigested contents of its stomach, this ankylosaur died quickly. It was surrounded by marine fossils, and researchers believe it slipped or fell into a large river, where it drowned and was swept out to sea.

“Whatever happened to the poor dinosaur, it would have happened pretty fast after it had eaten.”

This report by The Canadian Press was first published June 2, 2020

— Follow at @row1960 on Twitter

Bob Weber, The Canadian Press

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Fermenting ferns? Rare dinosaur stomach fossil opens door to ancient world – The Observer

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Fresh ferns, loaded with spores, lightly dusted with leaves and twigs and perfectly seasoned with locally sourced charcoal.

Sound good? It did to an ankylosaur about 110 million years ago, as evidenced by amazingly complete fossils of what was certainly the tank-like dinosaur’s last meal.

article continues below

“It’s pretty exciting,” said Caleb Brown, a curator at the Royal Tyrrell Museum of Paleontology and co-author of a paper published Tuesday on what is one of probably only three fossilized dinosaur stomachs discovered.

“We can start recontructing the life histories and ecologies of these animals.”

The dining dinosaur was first unearthed in 2011 in a northern Alberta Suncor oilsands mine, where many excavators have learned to look for fossils as they dig. When this one turned up, a crew from the Tyrrell followed shortly afterward.

It was an amazingly well-preserved ankylosaur from the early Cretaceous period. Low but large — the species could reach eight metres long and weigh eight tonnes — the fossil took two weeks to remove.

It then took 5 1/2 years for technician Mark Mitchell to clean and prepare it, which is why the species now bears the Latin name markmitchelli. The restored specimen, complete with body armour and outer skin, was remarkable enough for a 2017 National Geographic magazine feature.

But for paleontologists, the fun was just starting. They began looking at a fossilized structure that co-author Jim Basinger of the University of Saskatchewan described as looking like a “squashed basketball.”

It was in the right place for a stomach and it held gastroliths, small stones dinosaurs used to help digest their food, much as some birds do today.

“There’s a great mess of them and they’re quite distinctive,” said Basinger.

The scientists eventually compiled 16 pieces of evidence that the squashed basketball was, in fact, a stomach.

“It’s unquestionable,” Basinger said.

There are only two other fossilized stomachs in the world that scientists are this sure about. Neither opens doors to the past the way this one does.

About 80 per cent of this last meal was a particular species of ferns. The fossils are so well preserved their spores identify them.

There are bits of other plants and twigs so immaculate that their growth rings are being used to estimate weather at the time. And there is charcoal from burned woody material.

Brown points out ferns aren’t that nutritious. A beast this size would need digestion capable of getting the most from them.

That means this dinosaur may have fermented its food, much like many animals today.

“All big herbivores today use some form of fermentation,” Brown said. “For this animal, it was almost certainly fermenting those ferns.”

Which raises other interesting questions: How much fermented fern does it take to move an eight-tonne lizard? How much energy might it need? Where might that much fodder be found?

The charcoal provides a clue. It probably came from an ancient forest fire where ferns would have been abundant in the first flush of new growth, much as they are today.

“(The dinosaur) was taking advantage of a charred landscape,” Basinger said. Many modern animals do the same, chowing down on tender, nutritious and low-hanging new growth that follows the flames.

More than just reassembling skeletons, modern paleontology is starting to rebuild ecosystems that haven’t existed for millions and millions of years.

“That’s something we can start playing with,” Brown said.

The fossils tell individual stories, too.

Basinger said, given the undigested contents of its stomach, this ankylosaur died quickly. It was surrounded by marine fossils, and researchers believe it slipped or fell into a large river, where it drowned and was swept out to sea.

“Whatever happened to the poor dinosaur, it would have happened pretty fast after it had eaten.”

This report by The Canadian Press was first published June 2, 2020

— Follow at @row1960 on Twitter

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Western Canadian scientists discover what an armoured dinosaur ate for its last meal – Yorkton This Week

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More than 110 million years ago, a lumbering 1,300-kilogram, armour-plated dinosaur ate its last meal, died, and was washed out to sea in what is now northern Alberta. This ancient beast then sank onto its thorny back, churning up mud in the seabed that entombed it—until its fossilized body was discovered in a mine near Fort McMurray in 2011.  

Since then, researchers at the Royal Tyrrell Museum of Palaeontology in Drumheller, Alta., Brandon University (BU), and the University of Saskatchewan (USask) have been working to unlock the extremely well-preserved nodosaur’s many secrets—including what this large armoured dinosaur (a type of ankylosaur) actually ate for its last meal.  

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“The finding of the actual preserved stomach contents from a dinosaur is extraordinarily rare, and this stomach recovered from the mummified nodosaur by the museum team is by far the best-preserved dinosaur stomach ever found to date,” said USask geologist Jim Basinger, a member of the team that analyzed the dinosaur’s stomach contents, a distinct mass about the size of a soccer ball. 

“When people see this stunning fossil and are told that we know what its last meal was because its stomach was so well preserved inside the skeleton, it will almost bring the beast back to life for them, providing a glimpse of how the animal actually carried out its daily activities, where it lived, and what its preferred food was.”  

There has been lots of speculation about what dinosaurs ate, but very little known. In a just-published article in Royal Society Open Science, the team led by Royal Tyrrell Museum palaeontologist Caleb Brown and Brandon University biologist David Greenwood provides detailed and definitive evidence of the diet of large, plant-eating dinosaurs—something that has not been known conclusively for any herbivorous dinosaur until now. 

“This new study changes what we know about the diet of large herbivorous dinosaurs,” said Brown. “Our findings are also remarkable for what they can tell us about the animal’s interaction with its environment, details we don’t usually get just from the dinosaur skeleton.” 

Previous studies had shown evidence of seeds and twigs in the gut, but these studies offered no information as to the kinds of plants that had been eaten. While tooth and jaw shape, plant availability and digestibility have fuelled considerable speculation, the specific plants herbivorous dinosaurs consumed has been largely a mystery. 

So what was the last meal of Borealopelta markmitchelli (which means “northern shield” and recognizes Mark Mitchell, the museum technician who spent more than five years carefully exposing the skin and bones of the dinosaur from the fossilized marine rock)? 

“The last meal of our dinosaur was mostly fern leaves—88 per cent chewed leaf material and seven per cent stems and twigs,” said Greenwood, who is also a USask adjunct professor.  

“When we examined thin sections of the stomach contents under a microscope, we were shocked to see beautifully preserved and concentrated plant material. In marine rocks we almost never see such superb preservation of leaves, including the microscopic, spore-producing sporangia of ferns.” 

Team members Basinger, Greenwood and BU graduate student Jessica Kalyniuk compared the stomach contents with food plants known to be available from the study of fossil leaves from the same period in the region. They found that the dinosaur was a picky eater, choosing to eat particular ferns (leptosporangiate, the largest group of ferns today) over others, and not eating many cycad and conifer leaves common to the Early Cretaceous landscape.  

Specifically, the team identified 48 palynomorphs (microfossils like pollen and spores) including moss or liverwort, 26 clubmosses and ferns, 13 gymnosperms (mostly conifers), and two angiosperms (flowering plants). 

“Also, there is considerable charcoal in the stomach from burnt plant fragments, indicating that the animal was browsing in a recently burned area and was taking advantage of a recent fire and the flush of ferns that frequently emerges on a burned landscape,” said Greenwood. 

“This adaptation to a fire ecology is new information. Like large herbivores alive today such as moose and deer, and elephants in Africa, these nodosaurs by their feeding would have shaped the vegetation on the landscape, possibly maintaining more open areas by their grazing.”  

The team also found gastroliths, or gizzard stones, generally swallowed by animals such as herbivorous dinosaurs and today’s birds such as geese, to aid digestion.  

“We also know that based on how well-preserved both the plant fragments and animal itself are, the animal’s death and burial must have followed shortly after the last meal,” said Brown. “Plants give us a much better idea of season than animals, and they indicate that the last meal and the animal’s death and burial all happened in the late spring to mid-summer.” 

“Taken together, these findings enable us to make inferences about the ecology of the animal, including how selective it was in choosing which plants to eat and how it may have exploited forest fire regrowth. It will also assist in understanding of dinosaur digestion and physiology.” 

Borealopelta markmitchelli, discovered during mining operations at the Suncor Millennium open pit mine north of Fort McMurray, has been on display at the Royal Tyrrell Museum since 2017. The main chunk of the stomach mass is on display with the skeleton. 

Other members of the team include museum scientists Donald Henderson and Dennis Braman, and BU research associate and USask alumna Cathy Greenwood.  

Research continues on Borealopelta markmitchelli—the best fossil of a nodosaur ever found—to learn more about its environment and behaviour while it was alive. Kalyniuk is currently expanding her work on fossil plants of this age to better understand the composition of the forests in which it lived. Many of the fossils she will examine are in Basinger’s collections at USask. 

The research was funded by Canada Foundation for Innovation, Research Manitoba, Natural Sciences and Engineering Research Council of Canada, National Geographic Society, Royal Tyrrell Museum Cooperating Society, and Suncor Canada, as well as in-kind support from Olympus Canada. 

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