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How scientists found Earth's new minimoon and why it won't stay here forever – Space.com

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A weird “minimoon” found circling Earth likely won’t be there long.

The scientists who discovered the object on Feb. 15 estimate that, because of the instability of its path through space, the minimoon will likely leave Earth’s orbit sometime in April.

Astronomers know little about this minimoon — so little, in fact, that they can’t even say if it’s an artificial object, such as a dead satellite. However, they say, it’s most likely a small asteroid. And although the object poses no danger to Earth, it does show how changeable our neighborhood is.

Video: ‘Minimoon’ discovered around Earth. Here’s its orbit
Related:
See the increase in near-Earth asteroids NASA has discovered (video)

The international Gemini Observatory/NSF’s National Optical-Infrared Astronomy Research Laboratory/AURA/G. Fedorets (Image credit: The international Gemini Observatory/NSF’s National Optical-Infrared Astronomy Research Laboratory/AURA/G. Fedorets)

Information from the International Astronomical Union’s Minor Planet Center, which keeps observation records for all known asteroids, shows that the orbit of the minimoon doesn’t match the precise orbit of any known human-made object, Kacper Wierzchos, a senior research specialist for the Catalina Sky Survey and co-discoverer of the minimoon, told Space.com. The object’s orbit didn’t display any perturbations resulting from solar radiation pressure coming from the sun; such wiggles are common for human-made satellites in Earth’s orbit.

But Wierzchos said he doesn’t want to assume the minimoon is an asteroid quite yet. “The possibility it is artificial still exists, so I am trying to be cautious with every statement,” he said. “I’d hate it to be artificial after [everyone is] making a fuss [about the discovery].”

The NASA-funded Catalina program at the University of Arizona is an automated survey that scans the sky for fast-moving objects. On discovery night, Wierzchos and Catalina research specialist Theodore Pruyne happened to be at the telescope, Wierzchos said. On a good night, the survey can study around 40 near-Earth asteroids, which are typically objects astronomers already know about. But on Feb. 15, something in Catalina’s observations looked a little funny and didn’t match anything known by astronomers. The duo submitted the discovery to the Minor Planet Center, and other astronomers soon confirmed the find.

Data from the Catalina Sky Survey shows the recently discovered minimoon currently orbiting Earth. (Image credit: K. Wierzchos/T. Pruyne/University of Arizona/Catalina Sky Survey)

The newly identified object, now known as 2020 CD3, was very faint when it was discovered, at only about magnitude 20. (The lower the magnitude, the brighter the object.) That faintness stretches the capabilities of Catalina and is beyond what most amateurs can see in their telescopes. (Since then, the object has faded to magnitude 23, making it visible only to the largest professional telescopes.) 

In the nights after the discovery, Wierzchos and his collaborators kept following the object to try to determine its orbit. Their calculations showed that, most likely, the object was circling the sun and Earth’s gravity snatched it into our planet’s orbit sometime in 2017.

How did the minimoon go unnoticed for years? First, the sky is vast, and telescopes have limited time dedicated to searching for asteroids, Wierzchos said. He also cited the minimoon’s faintness and highly variable orbit.

2020 CD3 has a “chaotic” orbit, he said, because it is pulled between the gravity of the moon and the gravity of Earth. Its distance to Earth varies between the equivalent of 0.2 and 4.5 Earth-moon distances (The average distance to the moon is roughly 239,000 miles, or 384,000 kilometers.) When Wierzchos last observed the minimoon, on Wednesday (Feb. 26), it was roughly 2.5 lunar distances away, he said.

Because the object’s distance to Earth varies, so does its orbital period, or the time it takes the minimoon to circle Earth. Wierzchos said the object’s orbital period is difficult to measure precisely, but it seems to be about a month.

Astronomers have observed 2020 CD3 only about six or seven times so far, so they don’t have enough information yet to derive a “light curve,” which shows the variation in an object’s brightness. If they can get that data, Wierzchos said, it may help astronomers determine what kind of asteroid it is (if it is, indeed, an asteroid), how quickly it rotates and how big it is. 

Assuming the object is a common type of asteroid called a carbonaceous asteroid, Wierzchos said, the minimoon is probably about the size of a car. Ideally, he hopes other telescopes will be able to observe the object before it drifts away. Telescopes he would like to see participate include Puerto Rico’s Arecibo Observatory (which has radar optimized to get the shape and size of nearby asteroids) or large optical telescopes, such as the Keck Observatory in Hawaii.

Wierzchos is scouring past data from the Catalina Sky Survey to see if 2020 CD3 showed up in past imagery and went unnoticed. He hasn’t found such observations yet, but he said it’s possible that Catalina or other asteroid surveyors, such as the Asteroid Terrestrial-impact Last Alert System, have that information in their archives.

Wierzchos hopes Catalina will be able to see 2020 CD3 again before it fades. But astronomers are racing against the gravitational tug-of-war between Earth and our traditional moon. Before long, they know, the minimoon will drift out of sight, bound for new adventures. 

Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom and on Facebook

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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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