About 90 million years ago, a giant turtle in what is now central China laid a clutch of tennis ball-size eggs with extremely thick eggshells. One egg never hatched, and it remained undisturbed for tens of millions of years, preserving the delicate bones of the embryonic turtle within it.
In 2018, a farmer discovered the egg and donated it to a university. Now, a new analysis of this egg and its rare embryo marks the first time that scientists have been able to identify the species of a dinosaur-age embryonic turtle.
This specimen also sheds light on why its species, the terrestrial turtle Yuchelys nanyangensis, went extinct 66 million years ago at the end of the Cretaceous period, when the dinosaur-killing asteroid struck Earth. The thick eggshell allowed water to penetrate through, so clutches of eggs were likely buried in nests deep underground in moist soil to keep them from drying out in the arid environment of central China during the late Cretaceous, the researchers said.
While these turtles’ unique terrestrial lifestyle, thick eggs and underground nesting strategy may have served them well during the Cretaceous, it’s possible that these specialized turtles couldn’t adapt to the cooler “climatic and environmental changes following the end-Cretaceous mass extinction,” study co-researcher Darla Zelenitsky, an associate professor of paleobiology at the University of Calgary in Canada, told Live Science.
The farmer discovered the egg in Henan province, a region famous for the thousands of dinosaur eggs people have found there over the past 30 years, Zelenitsky said. But in comparison with dinosaur eggs, turtle eggs — especially those with preserved embryos — rarely fossilize because they’re so small and fragile, she said.
The Y. nanyangensis egg, however, persisted because it’s a tank of an egg.
At 2.1 by 2.3 inches (5.4 by 5.9 centimeters) in size, the nearly spherical egg is just a bit smaller than a tennis ball. That’s larger than the eggs of most living turtles, and just a tad smaller than the eggs of Galápagos tortoises, Zelenitsky said.
The eggshell’s 0.07 inch (1.8 millimeters) thickness is also remarkable. To put that in perspective, that’s four times thicker than a Galápagos tortoise eggshell, and six times thicker than a chicken eggshell, which has an average thickness of 0.01 inch (0.3 mm). Larger eggs tend to be thicker, like the 0.08-inch-thick (2 mm) ostrich eggshell, but “this egg is much smaller than an ostrich egg,” which average about 6 inches (15 cm) in length, Zelenitsky said.
An equation that uses egg size to predict the length of the carapace, or the top part of the turtle’s shell, revealed that this thick egg was likely laid by a turtle with a 5.3-foot-long (1.6 meters) carapace, the researchers found. That measurement doesn’t include the length of the neck or head, so the mother turtle was easily as long as some humans are tall.
The researchers used a micro-CT scan to create virtual 3D images of the egg and its embryo. By comparing these images with a distantly related living turtle species, it appears that the embryo was nearly 85% developed, the researchers found.
Part of the eggshell is broken, Zelenitsky noted, so “maybe it tried to hatch,” but failed. Apparently, it wasn’t the only embryonic turtle that didn’t make it; two previously discovered thick-shelled egg clutches from Henan province that date to the Cretaceous — one with 30 eggs and another with 15 eggs — likely also belong to this turtle’s now-extinct family, known as Nanhsiungchelyid, the researchers said.
Turtles in this family — relatives of today’s river turtles — were very flat and evolved to live entirely on land, which was unique during that time, Zelenitsky said.
The study of the newfound egg is special for its virtual 3D analysis of the embryo, which helped lead to its species diagnosis, said Walter Joyce, a professor of paleontology at the University of Fribourg in Switzerland, who was not involved in the study. Furthermore, this study offers evidence that Nanhsiungchelyid turtles were “adapted to living in harsh, terrestrial environments, but laid their large, thick-shelled eggs in covered nests in moist soil,” Joyce told Live Science in an email.
The study will be published online Wednesday (Aug. 18) in the journal Proceedings of the Royal Society B: Biological Sciences.
Originally published on Live Science.
Chinese astronauts return to Earth after 90 days aboard space station – CBC.ca
A trio of Chinese astronauts returned to Earth on Friday after a 90-day stay aboard their nation’s first space station in China’s longest mission yet.
Nie Haisheng, Liu Boming and Tang Hongbo landed in the Shenzhou-12 spaceship just after 1:30 p.m. local time after having undocked from the space station Thursday morning.
State broadcaster CCTV showed footage of the spacecraft parachuting to land in the Gobi Desert where it was met by helicopters and off-road vehicles. Minutes later, a crew of technicians began opening the hatch of the capsule, which appeared undamaged.
The three astronauts emerged about 30 minutes later and were seated in reclining chairs just outside the capsule to allow them time to readjust to Earth’s gravity after three months of living in a weightless environment. The three were due to fly to Beijing on Friday.
“With China’s growing strength and the rising level of Chinese technology, I firmly believe there will even more astronauts who will set new records,” mission commander Nie told CCTV.
After launching on June 17, the three astronauts went on two spacewalks, deployed a 10-metre mechanical arm and had a video call with Communist Party leader Xi Jinping.
While few details have been made public by China’s military, which runs the space program, astronaut trios are expected to be brought on 90-day missions to the station over the next two years to make it fully functional.
The government has not announced the names of the next set of astronauts nor the launch date of Shenzhou-13.
Source of national pride
China has sent 14 astronauts into space since 2003, when it became only the third country after the former Soviet Union and the United States to do so on its own.
China’s space program has advanced at a measured pace and has largely avoided many of the problems that marked the U.S. and Russian programs that were locked in intense competition during the heady early days of spaceflight.
That has made it a source of enormous national pride, complementing the country’s rise to economic, technological, military and diplomatic prominence in recent years under the firm rule of the Communist Party and current leader Xi Jinping.
WATCH |Chinese astronauts blast off, dock at space station:
China embarked on its own space station program in the 1990s after being excluded from the International Space Station, largely due to U.S. objections to the Chinese space program’s secrecy and military backing.
Space probe on Mars
China has simultaneously pushed ahead with uncrewed missions, placing a rover on the little-explored far side of the Moon and, in December, the Chang’e 5 probe returned lunar rocks to Earth for the first time since the 1970s.
China this year also landed its Tianwen-1 space probe on Mars, with its accompanying Zhurong rover venturing out to look for evidence of life.
Another program calls for collecting samples from an asteroid, an area in which Japan’s rival space program has made progress of late.
China also plans to dispatch another mission in 2024 to bring back lunar samples and is pursuing a possible crewed mission to the moon and eventually building a scientific base there, although no timeline has been proposed for such projects. A highly secretive space plane is also reportedly under development.
Tom Cruise gets sneak preview from SpaceX's 1st private crew – CTV News
CAPE CANAVERAL, FLA. —
Tom Cruise got a sneak preview of what it’s like to circle Earth in a SpaceX capsule.
Representatives for SpaceX’s first privately chartered flight revealed Friday that the actor took part in a call with the four space tourists orbiting more than 360 miles up. Thursday’s conversation, like the entire three-day flight, was private and so no details were released.
“Maverick, you can be our wingman anytime,” came the announcement from the flight’s Twitter feed. Cruise starred as Navy pilot Pete “Maverick” Mitchell in the 1986 film “Top Gun.” A sequel comes out next year.
Last year, NASA confirmed it was in talks with Cruise about visiting the International Space Station for filming. SpaceX would provide the lift, as it does for NASA astronauts, and like it did Wednesday night for the billionaire up there now with his two contest winners and a hospital worker.
Their flight is due to end Saturday night with a splashdown in the Atlantic off the Florida coast.
The four showed off their capsule in a live broadcast Friday. They’re flying exceedingly high in the automated capsule, even by NASA standards.
SpaceX got them into a 363-mile (585-kilometer) orbit following Wednesday night’s launch from NASA’s Kennedy Space Center. That’s 100 miles (160 kilometers) higher than the International Space Station. It’s so high that they’re completing 15 orbits of Earth daily, compared with 16 for station astronauts.
Until this all-amateur crew, relatively few NASA astronauts had soared that high. The most recent were the shuttle astronauts who worked on the Hubble Space Telescope over multiple flights in the 1990s and 2000s.
To enhance the views, SpaceX outfitted the Dragon capsule with a custom, bubble-shaped dome. Photos of them looking out this large window were posted online, otherwise little else had been publicly released of their first day in space.
Besides talking space with Cruise, the four capsule passengers chatted Thursday with young cancer patients. Hayley Arceneaux, a childhood cancer survivor, led the conversation from orbit with patients from the hospital that saved her life almost 20 years ago: St. Jude Children’s Research Hospital. A 6-year-old-boy wanted to know if there are cows on the moon – like in the nursery rhyme.
“I hope there will be one day. Right now, no, there aren’t,” replied another passenger, Sian Proctor. “We’re going to go back to the moon soon and we’re going to investigate all kinds of things about it.”
The video linkup was not broadcast live, but shared by St. Jude on Friday. Seeing the Earth from so high is “so beautiful,” Arceneaux told them.
Now a physician assistant at St. Jude, Arceneaux is the youngest American in space at age 29.
Pennsylvania entrepreneur Jared Isaacman, 38, purchased the entire flight for an undisclosed amount. He’s seeking to raise $200 million for St. Jude through the flight he’s named Inspiration4, half of that coming from his own pocket.
The two other Dragon riders won their seats through a pair of contests sponsored by Isaacman: Chris Sembroski, 42, a data engineer, and Proctor, 51, a community college educator.
During the broadcast Friday afternoon, Sembroski played a ukulele that will be auctioned off for St. Jude. “You can turn your volume down if you wish, but I’ll give it a shot,” he said.
Proctor, who is an artist, showed off a drawing in her sketchbook of a Dragon capsule being carried by a mythological dragon away from Earth.
All four share SpaceX founder Elon Musk’s quest to open space to everyone.
“Missions like Inspiration4 help advance spaceflight to enable ultimately anyone to go to orbit & beyond,” Musk tweeted Thursday after chatting with his orbiting pioneers.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.
Dark Energy Could Be Responsible for Mysterious Experiment Signals, Researchers Say – Gizmodo
A team of physicists at the University of Cambridge suspects that dark energy may have muddled results from the XENON1T experiment, a series of underground vats of xenon that are being used to search for dark matter.
Dark matter and dark energy are two of the most discussed quandaries of contemporary physics. The two darks are placeholder names for mysterious somethings that seem to be affecting the behavior of the universe and the stuff in it. Dark matter refers to the seemingly invisible mass that only makes itself known through its gravitational effects. Dark energy refers to the as-yet unexplained reason for the universe’s accelerating expansion. Dark matter is thought to make up about 27% of the universe, while dark energy is 68%, according to NASA.
Physicists have some ideas to explain dark matter: axions, WIMPs, SIMPs, and primordial black holes, to name a few. But dark energy is a lot more enigmatic, and now a group of researchers working on XENON1T data says an unexpected excess of activity could be due to that unknown force, rather than any dark matter candidate. The team’s research was published this week in Physical Review D.
The XENON1T experiment, buried below Italy’s Apennine Mountains, is set up to be as far away from any noise as possible. It consists of vats of liquid xenon that will light up if interacted with by a passing particle. As previously reported by Gizmodo, in June 2020 the XENON1T team reported that the project was seeing more interactions than it ought to be under the Standard Model of physics, meaning that it could be detecting theorized subatomic particles like axions—or something could be screwy with the experiment.
“These sorts of excesses are often flukes, but once in a while they can also lead to fundamental discoveries,” said Luca Visinelli, a researcher at Frascati National Laboratories in Italy and a co-author of the study, in a University of Cambridge release. “We explored a model in which this signal could be attributable to dark energy, rather than the dark matter the experiment was originally devised to detect.”
“We first need to know that this wasn’t simply a fluke,” Visinelli added. “If XENON1T actually saw something, you’d expect to see a similar excess again in future experiments, but this time with a much stronger signal.”
Despite constituting so much of the universe, dark energy has not yet been identified. Many models suggest that there may be some fifth force besides the known four known fundamental forces in the universe, one that is hidden until you get to some of the largest-scale phenomena, like the universe’s ever-faster expansion.
Axions shooting out of the Sun seemed a possible explanation for the excess signal, but there were holes in that idea, as it would require a re-think of what we know about stars. “Even our Sun would not agree with the best theoretical models and experiments as well as it does now,” one researcher told Gizmodo last year.
Part of the problem with looking for dark energy are “chameleon particles” (also known as solar axions or solar chameleons), so-called for their theorized ability to vary in mass based on the amount of matter around them. That would make the particles’ mass larger when passing through a dense object like Earth and would make their force on surrounding masses smaller, as New Atlas explained in 2019. The recent research team built a model that uses chameleon screening to probe how dark energy behaves on scales well beyond that of the dense local universe.
“Our chameleon screening shuts down the production of dark energy particles in very dense objects, avoiding the problems faced by solar axions,” said lead author Sunny Vagnozzi, a cosmologist at Cambridge’s Kavli Institute for Cosmology, in a university release. “It also allows us to decouple what happens in the local very dense Universe from what happens on the largest scales, where the density is extremely low.”
The model allowed the team to understand how XENON1T would behave if the dark energy were produced in a magnetically strong region of the Sun. Their calculations indicated that dark energy could be detected with XENON1T.
Since the excess was first discovered, the XENON1T team “tried in any way to destroy it,” as one researcher told The New York Times. The signal’s obstinacy is as perplexing as it is thrilling.
“The authors propose an exciting and interesting possibility to expand the scope of the dark matter detection experiments towards the direct detection of dark energy,” Zara Bagdasarian, a physicist at UC Berkeley who was unaffiliated with the recent paper, told Gizmodo in an email. “The case study of XENON1T excess is definitely not conclusive, and we have to wait for more data from more experiments to test the validity of the solar chameleons idea.”
The next generation of XENON1T, called XENONnT, is slated to have its first experimental runs later this year. Upgrades to the experiment will hopefully seal out any noise and help physicists home in on what exactly is messing with the subterranean detector.
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