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Are there more rogue planets than stars in our galaxy? – EarthSky

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Artist’s concept of rogue planet CFBDSIR J214947.2-040308.9. Researchers now think there could be more such nomadic planets than stars in our galaxy. Image via ESO/ L. Calçada/ P. Delorme/ Nick Risinger (skysurvey.org)/ R. Saito/ VVV Consortium.

There are some 100 to 400 billion stars in our Milky Way galaxy. Scientists now say there may be as many, or more, exoplanets or planets orbiting those distant stars. That’s incredible to ponder, but now consider this. Researchers at Ohio State University just announced a new study suggesting there may be more free-floating rogue planets – planets not orbiting any star – than stars in the Milky Way. Wow!

The theoretical, but fascinating, peer-reviewed conclusions were published in The Astronomical Journal on August 21, 2020.

What more, these scientists say, an upcoming NASA mission, the Nancy Grace Roman Space Telescope, should be able to find hundreds or more of these rogue planets. Astronomer Samson Johnson at Ohio State – lead author of the study – commented:

This gives us a window into these worlds that we would otherwise not have. Imagine our little rocky planet just floating freely in space; that’s what this mission will help us find.

As our view of the universe has expanded, we’ve realized that our solar system may be unusual. Roman will help us learn more about how we fit in the cosmic scheme of things by studying rogue planets.

Illustration of a rogue planet floating through space between the stars. Image via NASA/ JPL-Caltech/ R. Hurt (Caltech-IPAC).

These rogue worlds are called free-floating planetary-mass objects (FFPs) and have masses similar to planets that orbit stars. Scientists don’t yet know how they came to be cosmic wanderers, untethered to any stars, but it’s possible that they were once part of regular solar systems, and somehow broke free of their stars’ gravity. Roman should be able to provide more clues, and provide a better idea of how many are out there. According to Scott Gaudi at Ohio State and a co-author of the paper:

The universe could be teeming with rogue planets and we wouldn’t even know it. We would never find out without undertaking a thorough, space-based microlensing survey like Roman is going to do.

If scientists can start to build a census of the numbers of FFPs, that itself would help them figure out how they formed. Do they form around stars just like other planets and then get ejected from those planetary systems? Or do they form from gas and dust independently of stars? It’s also thought that the ejection of planets from their home planetary systems might be more common in denser star clusters, since more frequent encounters between stars in dense clusters will make the planetary systems unstable.

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Animation depicting how gravitational microlensing can reveal rogue planets. When an unseen rogue planet passes in front of a more distant star from our vantage point, light from the star bends as it passes through the warped space-time around the planet. The planet acts as a cosmic magnifying glass, amplifying the brightness of the background star. Image via NASA.

Roman will test various theories and models to see which ones come closest to explain these enigmatic worlds.

It is expected that Roman will be 10 times more sensitive in detecting these objects than previous searches. Roman will focus on searching for FFPs between our sun and the center of the galaxy. That search will span about 24,000 light-years in total. Johnson said:

There have been several rogue planets discovered, but to actually get a complete picture, our best bet is something like Roman. This is a totally new frontier.

According to the new paper, it is expected that Roman should find at least 250 FFPs, even ones as small as Mars.

Artist’s rendering of NASA’s upcoming Nancy Grace Roman Space Telescope. Image via NASA/ Ohio State News.

Last year, another study estimated that there could be 50 billion such nomad planets in our galaxy. About a dozen or so confirmed rogue planets have been found so far, and two of those were announced last year: OGLE-2012-BLG-1323 and OGLE-2017-BLG-0560. The first is estimated to have a mass between Earth and Neptune, while the other has a mass between Jupiter and a brown dwarf star.

Exoplanets orbiting stars can be difficult to detect, and rogue exoplanets even more so. How will Roman find them? It will use a technique called gravitational lensing, which relies on the gravity of stars and planets to bend and magnify the light coming from stars that pass behind them, from the telescope’s viewpoint. This technique can find exoplanets thousands of light-years from Earth, and is based on Albert Einstein’s theory of General Relativity. According to co-author Matthew Penny at Louisiana State University in Baton Rouge:

The microlensing signal from a rogue planet only lasts between a few hours and a couple of days and then is gone forever. This makes them difficult to observe from Earth, even with multiple telescopes. Roman is a game-changer for rogue planet searches.

Of course, another question is whether any rogue planets could support life. Johnson said it is probably unlikely since they have no stars for heat and energy:

They would probably be extremely cold, because they have no star.

Samson Johnson at The Ohio State University, lead author of the new study. Image via Ohio State News.

Discovering how rogue planets came to be will help astronomers figure out what makes them so unique and also better understand how regular planetary systems form. Johnson said:

If we find a lot of low-mass rogue planets, we’ll know that as stars form planets, they’re probably ejecting a bunch of other stuff out into the galaxy. This helps us get a handle on the formation pathway of planets in general.

Rogue planets are enigmatic objects, essentially planets as we know them but with no stars to call home. And there may be many more of them than ever thought possible.

Bottom line: New research shows that there could be more rogue, free-floating planets than stars in our galaxy.

Source: Predictions of the Nancy Grace Roman Space Telescope Galactic Exoplanet Survey. II. Free-floating Planet Detection Rates*

Via Ohio State News

Via NASA

An upcoming NASA mission, the Nancy Grace Roman Space Telescope, should be able to find hundreds or more of them.

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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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