Science: Mystery of prehistoric, alien-like tully monster deepens once more

Tully monsters haunted Earth’s oceans 300 million years ago and left behind such bizarre fossils that researchers haven’t even agreed on whether these strange creatures had backbones. Now, more than 60 years after the strange creature’s discovery in 1958, a new investigation using 3D lasers finds that the Tully monster was likely an invertebrate, but not everyone is convinced.

This alien-looking evolutionary oddball — only found in the Mazon Creek fossil beds in Illinois — had a soft body, eyes on stalks, and a claw-like appendage coming out of its face. Other aspects of its anatomy, however, are open to interpretation.

The latest research, published April 16 in the journal Palaeontology, is one of a slew of studies attempting to classify the creature.

Most recent Tully monster (Tullimonstrum gregarium) studies argue that it’s either a vertebrate relative of modern cyclostomes (including lampreys and hagfish) in the chordate group or an unknown invertebrate. Now, researchers in Japan think they’ve cracked the case, with the help of a 3D laser scanner.

"We believe that the mystery of it being an invertebrate or vertebrate has been solved," first author Tomoyuki Mikami, a doctoral student at the University of Tokyo and a researcher at the National Museum of Nature and Science in Tokyo, said in a statement. "Based on multiple lines of evidence, the vertebrate hypothesis of the Tully monster is untenable."

Related: Ancient ‘Tully monster’ was a vertebrate, not a spineless blob, study claims

The researchers scanned more than 150 Tully monster fossils to create color-coded 3D maps of the animal’s anatomical structures. They also X-rayed one well-preserved proboscis — the claw-like appendage — to examine the creature’s teeth.

The results suggested that features previously used to argue Tully monsters are near cyclostomes taxonomically, including their teeth and gill pouches, were misinterpreted. The teeth analyzed in the new study had bulging bases — unlike cyclostome teeth, which are thinner at the base. The authors said what appeared to be gills was actually just segmentation in the body.

Most convincing of all, the team claims, is segmentation found on the creature’s head. "This characteristic is not known in any vertebrate lineage, suggesting a nonvertebrate affinity," Mikami said.

Victoria McCoy, an assistant professor at the University of Wisconsin-Milwaukee, is not convinced, however. McCoy led a 2016 study placing Tully monsters near cyclosomes and a 2020 study that found Tully monster tissues were made up of proteins like those of vertebrates — and not chitin, like those of invertebrates.

"It didn’t change my mind about what the Tully monster was," McCoy told Live Science. "But it is new information, and that definitely advances our understanding."

McCoy was excited by the researchers’ application of 3D imaging but had "minor technical quibbles with some of their conclusions." She argued that cyclostomes are very diverse in the fossil record and thus some species could have had the bulging-based teeth documented in the study. She also noted that the anatomy of animals preserved in Mazon Creek separates and shifts, which could account for the appearance of segmentation.

"The real-life morphology gets changed a lot during fossilization," McCoy said. "If you have a thousand specimens, any one feature might be preserved a hundred different ways."

Deciding where the Tully monster belongs is significant because the species is so unusual that it will expand the diversity of whatever group it ends up in, changing the way we think about that group.

The latest study also puts forward a potential compromise for the discrepancies: that Tully monsters could possibly be nonvertebrate chordates like modern tunicates or lancelets. For now, however, the Tully monster’s place on the evolutionary tree remains unclear.

Source: https://www.livescience.com/animals/extinct-species/mystery-of-prehistoric-alien-like-tully-monster-deepens-once-more

Space: NASA’s 1st nuclear-powered rocket could launch as soon as 2025

[I can't wait to see nuclear powered rockets! Now you're going in the right direction! Jan]

The U.S. plans to launch the world’s first nuclear-powered spacecraft into orbit as early as 2025, NASA and the Defense Advanced Research Projects Agency (DARPA) have announced.

The $499 million mission, named Demonstration Rocket for Agile Cislunar Operations (DRACO), will be the first test for a new type of rocket propulsion system that the agencies claim could send astronauts to Mars in just 45 days.

The agencies, which have partnered to develop the rocket, announced on July 26 that they had reached an agreement with the U.S. defense contractor Lockheed Martin to design, build and test the prototype.

Related: To the moon! NASA launches Artemis 1, the most powerful rocket ever built

"We’re going to put this together, we’re going to fly this demonstration, gather a bunch of great data and really, we believe, usher in a new age for the United States [and] for humankind, to support our space exploration mission," Kirk Shireman, vice president of Lockheed Martin Lunar Exploration Campaigns, said during a press conference.

NASA’s current rocket systems — including the Space Launch System that last year sent the Artemis 1 rocket on a historic round-trip to the moon — are based on the century-old method of chemical propulsion, in which flammable rocket fuel is mixed with an oxidizer to create a flaming jet of thrust.

The proposed nuclear system, on the other hand, will harness the chain reaction from ripping apart atoms to power the spacecraft. The nuclear fission reactor will be "three or more times more efficient" and could reduce Mars flight times to a fraction of the current seven months, NASA said.

Nuclear engines generate less maximum thrust than their chemical counterparts but can fire more efficiently for extended periods of time — propelling rockets at much higher speeds and for significantly longer portions of their journey.

NASA began its research into nuclear thermal engines in 1959, eventually leading to the design and construction of the Nuclear Engine for Rocket Vehicle Application (NERVA), a solid-core nuclear reactor that was successfully tested on Earth. Plans to fire the engine in space, however, were scrapped following the end of the Apollo missions in 1973 and a sharp reduction in the program’s funding.

DRACO’s reactor will work by splitting uranium atoms inside a nuclear reactor — a process that will superheat hydrogen before blasting it out of the spacecraft’s thruster to push it forward.

Before it is heated to a searing 4,400 degrees Fahrenheit (2,427 degrees Celsius), DRACO’s hydrogen propellant will need to be kept at an ultra-cold minus 420 F (minus 251 C) — a major challenge for the spacecraft’s developers.

"Our life-limiting factor is how long we can keep the hydrogen cryogenic," Tabitha Dodson, the DRACO program manager at DARPA, said during the press briefing. "This is just as much a demonstration of on-orbit storage of cryogenic liquid hydrogen as it is a demo of the nuclear thermal rocket engine."

Once the spacecraft is assembled, it will be sent into a high orbit between 435 miles and 1,240 miles (700 to 2,000 kilometers) above Earth, allowing it to last roughly 300 years in orbit — long enough for its dangerously radioactive fuel to decay to safe levels, Dodson said.

Source: https://www.livescience.com/space/space-exploration/nasas-1st-nuclear-powered-rocket-could-launch-as-soon-as-2025

Space: Amazing little helicopter on Mars: Mars helicopter Ingenuity spies Perseverance rover during 54th Red Planet flight (photo, video)

[This little helicopter is amazingly successful. The photos and video are at the source link below. Jan]

NASA’s Mars helicopter Ingenuity just snapped a photo of its Red Planet partner.

Ingenuity captured an image of NASA’s Perseverance rover on Aug. 3, during the 4-pound (1.8 kilograms) chopper’s 54th Mars flight.

Perseverance is nearly out of frame at the top of the photo, which Ingenuity took when it was about 16 feet (5 meters) above the red dirt.

Related: Mars helicopter Ingenuity phones home, breaking 63-day silence

Unlike previous sorties, the Aug. 3 flight wasn’t a scouting run to aid Perseverance’s science activities. It lasted just 24 seconds, reached a maximum altitude of 16 feet and covered no ground laterally, according to Ingenuity’s flight log.

The mission team designed this short and simple hop in an attempt to help understand what happened during Ingenuity’s previous flight, which was cut short unexpectedly.

That July 22 sortie was supposed to last 136 seconds and feature several complicated maneuvers. However, Ingenuity stayed aloft for just 74 seconds, touching down after something triggered its "flight-contingency program."

"Since the very first flight, we have included a program called ‘LAND_NOW’ that was designed to put the helicopter on the surface as soon as possible if any one of a few dozen off-nominal scenarios was encountered," Teddy Tzanetos, Ingenuity team lead emeritus at NASA’s Jet Propulsion Laboratory in Southern California, said in a statement.

"During Flight 53, we encountered one of these, and the helicopter worked as planned and executed an immediate landing," Tzanetos added.

Flight 53, by the way, was the first hop for Ingenuity in nearly three months. The little drone was ground bound for so long because rough terrain on the floor of Mars’ Jezero Crater blocked its communications with Perseverance. (All commands to, and data relays from, Ingenuity are routed through the rover.)

Tzanetos and his colleagues think they know what triggered LAND_NOW: Imagery from Ingenuity’s navigation camera likely got out of sync with its inertial measurement unit, which helps the little chopper determine its position, speed and orientation.

This also happened near the end of Ingenuity’s sixth flight, back in May 2021. The mission team soon uploaded a software patch to deal with the issue, but that patch apparently couldn’t handle what happened on Flight 53, NASA officials said in the statement.

"While we hoped to never trigger a LAND_NOW, this flight is a valuable case study that will benefit future aircraft operating on other worlds," Tzanetos said. "The team is working to better understand what occurred in Flight 53, and with Flight 54’s success, we’re confident that our baby is ready to keep soaring ahead on Mars."

Ingenuity and Perseverance landed together on Jezero’s floor in February 2021. The helicopter quickly aced its primary mission, a five-flight technology demonstration. It then moved on to an extended mission, during which it performed reconnaissance for the Perseverance team.

This isn’t the first time that such scouting work has resulted in a photo of Perseverance. For example, the rover made it into frame during Ingenuity’s 51st flight, which occurred on April 22.

Source: https://www.space.com/mars-helicopter-ingenuity-perseverance-photo-54th-flight

Science: Scottish fossil of flying reptile leaves scientists gobsmacked

A fossil jawbone peeking out from a limestone seashore on Scotland’s Isle of Skye led scientists to discover the skeleton of a pterosaur that showed that these remarkable flying reptiles got big tens of millions of years earlier than previously known.

Researchers said on Tuesday this pterosaur, named Dearc sgiathanach, lived roughly 170 million years ago during the Jurassic Period, soaring over lagoons in a subtropical landscape and catching fish and squid with crisscrossing teeth perfect for snaring slippery prey.

Its scientific name, pronounced “jark ski-an-ach,” means “winged reptile” in Gaelic.

With a wingspan of about 8 feet (2.5 meters), Dearc was the Jurassic’s largest-known pterosaur and the biggest flying creature that had inhabited Earth to that point in time. Some pterosaurs during the subsequent Cretaceous Period achieved much greater dimensions – as big as fighter jets. But Dearc shows that this scaling up had its origins much earlier.

A forensic analysis of its bones indicated this Dearc individual was not fully grown and could have had a 10-foot (3-meter) wingspan as an adult.

Dearc weighed very little – probably below 22 pounds (10 kg) – thanks to its hollow, lightweight bones and slender structure, said University of Edinburgh paleontology doctoral student Natalia Jagielska, lead author of the research published in the journal Current Biology.

It had an elongated skull and a long, stiff tail. An arsenal of sharp teeth formed a cage when it bit down on prey.

Pterosaurs, which lived alongside the dinosaurs, were the first of three vertebrate groups to achieve powered flight, appearing about 230 million years ago. Birds appeared about 150 million years ago and bats around 50 million years ago.

Pterosaurs are some of the rarest vertebrates in the fossil record owing to their fragile bones, some with walls thinner than a sheet of paper.

“Our specimen, anomalously, is well preserved – retaining its original three dimensions and being almost complete, and still articulated as it would be when alive. Such state of preservation is exceptionally rare in pterosaurs,” Jagielska said.

Up until when Dearc lived, pterosaurs generally had been modest in size, many about the size of a seagull. The prevailing wisdom among scientists had been that pterosaurs did not reach Dearc’s size until the Cretaceous, some 25 million years later, with the appearance of creatures like Huanhepterus, Feilongus and Elanodactylus. Quetzalcoatlus, appearing about 68 million years ago, boasted a wingspan of about 36 feet (11 meters), like an F-16 fighter.

“In the Cretaceous, some pterosaurs got enormous. These were some of the most superlative animals that ever lived. Dearc was not close to them in size or grandeur, but it was 100 million years older. Evolution needed time to make such giants,” University of Edinburgh paleontologist and study co-author Steve Brusatte said.

“One idea is that pterosaurs only got larger after birds evolved, when the two groups were competing with each other for the aerial niches. But Dearc tells us that pterosaurs already got to be the size of today’s largest birds even before the first birds evolved, so it throws a wrench into this idea,” Brusatte added.

In Dearc’s time, Britain was closer to the equator and existed as a series of smaller separate islands. Dearc lived alongside a menagerie of plant-eating and meat-eating dinosaurs, early mammals and marine reptiles.

Dearc was discovered in 2017, with the fossil jutting out from a limestone intertidal zone after the tide had gone down.

“We were gobsmacked,” Brusatte said. “Nothing like this had ever been found in Scotland.”

They battled the tide, first using hammers and chisels and then diamond-tipped saws. But the tide interrupted before the skeleton could be fully extracted.

“The tide came in with a vengeance, and we cried as the waves lapped over the fossil,” Brusatte said. “We thought we lost it. But we decided to come back around midnight when the tide was down again, using our headlamps and flashlights. We were shocked and relieved to see the bones still there as the waves receded.”

Source: https://www.dailymaverick.co.za/article/2022-02-22-scottish-fossil-of-flying-reptile-leaves-scientists-gobsmacked/?utm_medium=email&utm_campaign=After