Dog-sized scorpions, dinosaur shrimp, and exoplanet collisions lead the week in science

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From megafauna and massive anthropods to an exoplanet hit so hard it was literally knocked out of the wind, the science news was definitely brisk this week.

On the biological front, a newly discovered fossil of a meter-long scorpion was the first of its kind in Asia, while scientists now believe they have conclusively proven what killed the woolly mammoth. Visitors to the Arizona park were also treated to the rare appearance of “dinosaur shrimp,” whose ancestors date back to before the reign of the dinosaurs.

On the science front, researchers have come closer than ever to absolute zero, the coldest temperature that matter can physically reach, with an exotic state of aggregation and a really tall tower.

Out in space, astronomers caught a white dwarf star that turned itself off and on again, while another team discovered evidence of an exoplanetary collision that can only be described as doozy.

Ancient dog-sized scorpion fossil found in China

A fossil of Terropterus xiushanensis gen. Et sp.  November and a sketch of what it would have looked like

(Photo credit: Han Wang et al.)

A large, prehistoric fossil of a sea scorpion was found in the Lower Silurian Mountains in southern China, the first time a large Eurypterid has been identified in Asia.

The fossil that belonged Terropterus xiushanensis Gen. et sp. nov., was a member of the Mixopterid, a branch of the Eurypterid (sea scorpion) characterized by special arms lined with spiky teeth that were used to gather prey in a terrible, basket-like embrace.

“Our knowledge of these bizarre animals is limited to only four species in two genera described 80 years ago: Mixopterus kiaeri from Norway, Mixopterus multispinosus from New York, Mixopterus simonsoni from Estonia and Lanarkopterus dolichoschelus from Scotland,” the researchers write in the study.

This new discovery expands our knowledge of these prehistoric sea predators, who lived 443.8 million to 419.2 million years ago.

Scientists reach coldest temperature ever recorded

The drop tower of the University of Bremen, with which the coldest temperature ever measured was reached

(Photo credit: Henning Christoph / ullstein bild via Getty Images)

In a record-breaking experiment, scientists in Germany reached the coldest temperature ever measured, only 38 trillionths of a Kelvin above absolute zero, the physical limit of how “cold” matter can be.

The temperature is a measure of the molecular movement. The more movement, the more molecules collide with each other, creating energy that we experience as heat. So the coldest possible temperature is reached when there is no molecular movement at all, which occurs at -459.67 ° F / -273.15 ° C, or 0 on the Kelvin scale.

In order to reach a temperature of 38 picokelvin, the scientists had to force around 100,000 rubidium atoms into an exotic aggregate state called Bose-Einstein condensate and then simulate space conditions with the 120-meter-high drop tower at the University of Bremen. Read more about this record breaking experiment here.

Three-eyed “dinosaur shrimp” surprise park goers

Triops australiensis in muddy water after rain in Australia

(Photo credit: Auscape / Universal Images Group via Getty Images)

Last July, monsoons in Arizona resulted in the hatching of hundreds of three-eyed “dinosaur shrimp”, which wowed visitors to Arizona’s Wupatki National Monument.

The long-tailed tadpole shrimp, officially Triops longicaudatus, were spotted swimming in a pool created by the rains that filled a preserved ball court at the historic site. “We knew there was water on the ball court, but we didn’t expect it would live in it,” said Lauren Carter, senior interpreter for the monument, to our colleagues at LiveScience. “Then a visitor came and said, ‘Hey, you have tadpoles on your ball court.'”

Although sometimes referred to as a “living fossil,” the description is not entirely accurate. The morphology of the Triops has remained largely unchanged for 70 million years, which does not mean that they are the same shrimp that coexisted with the dinosaurs.

“I don’t like the term ‘living fossil’ because it creates a misunderstanding among the public that they haven’t changed at all,” Carter said. “But they have changed, they have evolved. Only outwardly they are very similar to what they were millions of years ago.”

Astronomers watch white dwarf “turn on and off”

An accretion material for white dwarfs from its partner star

(Photo credit: NASA / CXC / M.Weiss)

Astronomers at Durham University, UK, were looking at data from NASA’s Transiting Exoplanet Survey Satellite (TESS) when they discovered something remarkable: a white dwarf star that “turns on and off” in just 30 minutes.

Dr. Simone Scaringi, who led the new research, examined the mechanics of material accretion around the white dwarf in order to get a better understanding of how accretion works with more exotic and therefore rarer objects such as black holes and neutron stars than the “switching behavior” .

The white dwarf is part of a binary star system known as TW Pictoris, and the white dwarf soaks up material from its partner star, making it a valuable object to watch accretion at work.

“In general, there are no short-term ‘gaps’ in the accretion process,” said Dr. Scaringi to TechRadar. “What generally happens with such systems is that the donor star in orbit around the white dwarf continues to feed the accretion disk. As the accretion disc material slowly sinks closer to the white dwarf, it generally becomes lighter and eventually ends up on the white dwarf surface. “

Scaringi believes that something about the white dwarf’s magnetic field is acting as a kind of magnetic gate mechanism that has not previously been observed.

“If the amount of material has almost completely run out, the so-called ‘magnet gating’ takes effect: The rotating magnetospheric barrier of the white dwarf prevents the remaining plate material from simply growing smoothly, but instead regulates the amount that ends up on the white dwarf “Seizures and starts”.

“Since it takes months to empty a hard drive, it was completely unexpected that TW Pictoris would decrease its brightness in 30 minutes,” Scaringi told us. “What we think could happen in TW Pictoris is that instead of deflating the disc so quickly, we see some kind of reconfiguration of the white dwarf magnetic field that immediately pushes the inner disc rim outward, making it weaker.”

Climate change has brought the woolly mammoth to extinction

A trio of woolly mammoths trudges over snow-covered hills with a mountain range in the background.

(Photo credit: Daniel Eskridge)

Woolly mammoths have had an endless fascination with humans since their discovery in 1796, but for the past hundred years there has been a heated debate over what drove these cousins ​​of the modern elephant to extinction. Now, a comprehensive study of nearly 20 years of biological samples says the woolly mammoth succumbed to climate change, not human activity.

“Scientists have been arguing for 100 years why mammoths became extinct,” said Professor Eske Willerslev, director of the Lundbeck Foundation’s GeoGenetics Center at the University of Copenhagen and a fellow at St John’s College, Cambridge University.

“People were accused of surviving millions of years without climate change killing them, but when they lived with humans they didn’t last long and we were accused of chasing them to death.

“We were finally able to prove that it wasn’t just climate change that was the problem, but the speed that was the last nail in the coffin – they couldn’t adapt fast enough when the landscape changed dramatically and” their food was running out. “

When the glaciers melted after the last Ice Age, climate change was so drastic that the snow-capped steppes and stubborn flora that fed the huge herds of megafauna disappeared. What it replaced was a wetter tundra with a radically different flora that was unsuitable for the huge herds of mammoths.

Even if people are technically relieved when the mammoth dies, that does not mean that there are no important lessons to be learned from the mammoth’s demise.

“It’s a great lesson from history and shows how unpredictable climate change is,” said Professor Willerslev, “once something is lost, there is no turning back. Precipitation was the cause of the extinction of the woolly mammoth due to the changes in the plants. The change happened so quickly that they couldn’t adapt and evolve to survive.

“It shows that nothing is guaranteed when it comes to the effects of dramatic weather changes. Early humans would have seen the world change beyond recognition – that could easily happen again and we cannot assume that we will even see it. The only thing we can predict with certainty is that the change will be massive. “

Exoplanet destroyed atmosphere by collision

The hypothetical protoplanet Theia collided with early Earth about 4.5 billion years ago

(Photo credit: future)

This week, astronomers announced that they had found evidence of an exoplanet collision so severe that it robbed much of its atmosphere from the planet it struck.

The planet in question is in the star system HF 172555, which is home to a relatively young star that is only about 23 million years old. The system is particularly interesting as there is still active planet formation and an examination of the amount of gas between the protoplanetary debris provides strong evidence of a violent collision in the recent past.

By studying the amount of carbon monoxide (CO) present in the debris disk around the star, which is normally broken down fairly quickly by stellar radiation, the astronomers found that about 200,000 years ago there was a collision between an Earth-sized planet and a smaller one Impactor that wrested a large part of its CO atmosphere from the larger planet.

For comparison: the amount of CO gas in the disk shows that the collision stripped a volume of about 20% of the Venusian atmosphere and threw it into orbit around the star.

“This is the first time we’ve discovered this stripped protoplanetary atmosphere phenomenon in a giant impact,” says Tajana Schneiderman, a PhD student in MIT’s Department of Earth, Atmospheric and Planetary Sciences and lead author of the new study this week in the journal Nature published. “Everyone is interested in seeing a huge impact because we expect it to happen frequently, but we have no evidence of it in many systems. Now we have additional insights into these dynamics. “


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