Category Archives: Science

Science

NASA delays moon lander awards as Biden team mulls moonshot program

Leave a comment

NASA last week quietly delayed its plan to award two high-profile crewed lunar lander contracts, moving the finish line back two months for a crucial program under the Trump administration’s hasty timeline to get astronauts on the moon in 2024. With short funding from Congress and a new administration focused on more pressing national issues, the move was expected.

Elon Musk’s SpaceX, a team of aerospace giants led by Jeff Bezos’ Blue Origin, and Leidos-owned Dynetics won a combined $967 million in seed funding from NASA last year to develop rivaling concepts for a human lunar landing system. It’s the space agency’s first effort to spend money on astronaut moon landers since the Apollo program in the 1970s.

Last Wednesday, NASA told the three contractors that an extension to their development contracts “will be required,” picking a new award date of April 30th. Under the Trump administration’s timeline, the agency had planned to pick two of the three bidders in late February, giving a stamp of approval for two systems that would inevitably carry humans to the moon.

The delay was all but certain: The spending bill Congress passed in December gives NASA $850 million for the Human Landing System program, far short of the $3.2 billion it needed to stick with the 2024 timeline. But NASA remained committed to the February award date and, similarly, the 2024 moonshot. A delay was also expected as Biden’s team holds off on releasing any space policy and focuses more on climate change and curbing the pandemic, keeping the long-term fate of NASA’s Artemis program uncertain.

Now, NASA says the delay is designed to give it more time to evaluate the bidders’ proposals and to “preserve the ability to seamlessly transition” from the development phase, but added it may not need the full extension period and could award the lander contracts earlier. The extension also gives the companies more time to design and develop their lander systems, NASA said.

SpaceX’s lunar lander pitch to NASA is Starship, a roughly 16-story-tall fully reusable vehicle the company has been launching and landing in short, suborbital test flights — called “hops” — in Boca Chica, Texas. The company’s chunk of development funds was $135 million.

Jeff Bezos’ Blue Origin got the largest award, $579 million, to develop its Blue Moon lander. The company announced a “National Team” in 2019 comprised of Lockheed Martin, Northrop Grumman and Draper to work on the project. Dynetics got $253 million for its lander and has partnered with Sierra Nevada Corp.

The Biden administration has yet to pick its NASA administrator or release any space policy objectives, but is expected to slow down the Artemis program’s sprint to the moon by 2024 — a date widely viewed as unrealistic. This month, the administration announced its team for the White House’s Office of Science and Technology Policy, picking pioneering geneticist Eric Lander as Biden’s top science adviser.

Trump’s NASA chief Jim Bridenstine left office on inauguration day after serving since 2018 and spawning the Artemis program. He handed the agency’s control to his No. 2, Steve Jurczyk as acting administrator.

Read original article here

Science

Amazon’s Ring now reportedly partners with more than 2,000 US police and fire departments

Leave a comment

All but two US states — Montana and Wyoming— now have police or fire departments participating in Amazon’s Ring network, which lets law enforcement ask users for footage from their Ring security cameras to assist with investigations, the Financial Times reported, Figures from Ring show more than 1,189 departments joined the program in 2020 for a total of 2,014. That’s up sharply from 703 departments in 2019 and just 40 in 2018.

The FT reports that local law enforcement departments on the platform asked for Ring videos for a total of more than 22,335 incidents in 2020. The disclosure data from Ring also shows that law enforcement made some 1,900 requests — such as subpoenas, search warrants, and court orders— for footage or data from Ring cameras even after the device owner has denied the request. Amazon complied with such requests 57 percent of the time, its figures show, down from 68 percent in 2019.

Privacy advocates have raised concerns about how Ring data is used by and made available to law enforcement. Ring’s Neighbors app, which allows Ring users to share videos with others nearby has been criticized for containing racist comments and reports. And a report from NBC News last February found that Ring footage wasn’t all that helpful for solving crimes. When it was useful, the Ring footage was mostly used for low-level non-violent property crimes (like the theft of a Nintendo Switch).

Ring began adding support for end-to-end encryption on its cameras earlier this month.

Read original article here

Science

Here’s How a 635 Million-Year-Old Microfossil May Have Helped Thaw ‘Snowball Earth’

Leave a comment

An international team of scientists in South China accidentally discovered the oldest terrestrial fossil ever found, about three times more ancient than the oldest known dinosaur.

 

Investigations are still ongoing and observations will need to be independently verified, but the international team argues the long thread-like fingers of this ancient organism look a lot like fungi.

Whatever it is, the eukaryote appears to have fossilised on land roughly 635 million years ago, just as Earth was recovering from a global ice age.

During this massive glaciation event, our planet resembled a big snowball, its oceans sealed from the Sun by more than a kilometre (0.6 miles) of solid ice. And then, in a geologic ‘flash’, our world began to inexplicably thaw, allowing life to thrive on land for the first time.

Fungi might have been among the first life forms to colonise that fresh space. The date of this new microfossil certainly supports the emerging idea that some fungi-like organisms ditched the oceans for a life on land even before plants.

In fact, this transition might have been what helped our planet recover from such a catastrophic ice age.

“If our interpretation is correct, it will be helpful for understanding the paleoclimate change and early life evolution,” says geobiologist Tian Gan, from the Virginia Tech College of Science. 

 

Today, the early evolution of fungi remains a big mystery, in large part because without bones or shells, these organisms do not fossilise easily. Not too long ago, many scientists didn’t even think it was possible for fungi to last that long.

The genome of modern-day fungi suggests their common ancestor lived over a billion years ago, branching off from animals at that time, but unfortunately, there could be a 600 million year break before the first obvious fungi fossil shows up in our records.

In recent years, a stream of intriguing and contentious discoveries have helped bridge that gap. 

In 2019, scientists reported the discovery of a fungi-like fossil in Canada, which had fossilised a billion years ago in an estuary. The implications were huge – namely that the common ancestor of fungi may have been around much earlier than the common ancestor of plants.

In 2020, a similar fossil with a resemblance to fungi was found in the Democratic Republic of Congo, and it was fossilised in a lagoon or lake between 810 and 715 million years ago.

 

Controversy still exists over whether or not these ancient organisms were actually fungi, and the new microfossil found in China will no doubt spur similar debate. After carefully comparing the organism’s features to other fossils and living life forms, the authors identify it is a eukaryote and “probable fungi”. 

“We would like to leave things open for other possibilities, as a part of our scientific inquiry,” says geoscientist Shuhai Xiao from Virginia Tech.

“The best way to put it is that perhaps we have not disapproved that they are fungi, but they are the best interpretation that we have at the moment.”

That said, the new discovery provides more evidence that fungi-like organisms may have predated plants on land.

“The question used to be: ‘Were there fungi in the terrestrial realm before the rise of terrestrial plants’,” explains Xiao. 

“And I think our study suggests yes.”

The next question is: How did that fungi survive? 

Today, many species of terrestrial fungi are incapable of photosynthesis. As such, they rely on a mutualistic relationship with the roots of plants, exchanging water and nutrients from rocks and other tough organic matter for carbohydrates.

 

Because of this relationship, it was thought that plants and fungi emerged together to help populate the land. But the oldest terrestrial plant fossil only dates to 470 million years ago. 

The recently unearthed fungi-like microfossil is much older than that and was found hidden within the small cavities of limestone dolostone rocks, located in the Doushantuo Formation in South China.

The rock in which the fossil was found appears to have been deposited roughly 635 million years ago, after our snowball Earth had melted. Once open to the elements, the authors suspect carbonate cement began to fill in the cavities between the sheets of limestone, possibly entombing the micro-organisms living inside these bubbles.

These fungi-like life forms might even have roomed with other terrestrial micro-organisms, which were also widespread at the time, such as cyanobacteria or green algae.

If fungi-like animals were equally ubiquitous, then it’s possible these life forms helped accelerate chemical weathering, delivering phosphorus to the seas and triggering a wave of bioproductivity in the marine environment.

On land, they might have even helped unearth clay minerals for carbon sequestration in Earth’s soil, making a fertile environment for plants and animals and possibly changing the very atmosphere of our planet.

“Thus,” the authors conclude, “the Doushantuo fungus-like micro-organisms, as cryptic as they were, may have played a role in catalyzing atmospheric oxygenation and biospheric evolution in the aftermath of the terminal Cryogenian global glaciation.”

The study was published in Nature Communications. 

 

Read original article here

Science

Antarctic ice shows traces of Martian mineral

Leave a comment

The yellow-brown mineral was detected with X-ray absorption testing and electron microscopy in samples found below 1000 metres depth

In detail, the researchers believe their discovery backs a theory that suggested that Mars may have been covered by an ice blanket billions of years ago and that this coverage had dust blowing into it, thus, leading to the formation of jarosite in ice pockets. 

In Antarctica, the team led by Giovanni Baccolo from the University of Milano-Bicocca detected the yellow-brown mineral with X-ray absorption testing and electron microscopy in samples found below 1000 metres depth. 

Jarosite was adhering to residual silica-rich particles, which have been identified in the Talos Dome ice core and interpreted as products of weathering involving aeolian dust and acidic atmospheric aerosols. 

“The progressive increase of ice metamorphism and re-crystallization with depth, favours the relocation and concentration of dust and the formation of acidic brines in isolated environments, allowing chemical reactions and mineral neo-formation to occur,” their paper reads. “This is the first described englacial diagenetic mechanism occurring in deep Antarctic ice and supports the ice-weathering model for jarosite formation on Mars.”

Even though their findings back the model, they still have to come up with a solid explanation as to why Antarctica contains small amounts of jarosite while on the red planet the mineral is found in large slabs.



Read original article here

Science

A curious observer’s guide to quantum mechanics, pt. 4: Looking at the stars

Leave a comment

Aurich Lawson / Getty Images

One of the quietest revolutions of our current century has been the entry of quantum mechanics into our everyday technology. It used to be that quantum effects were confined to physics laboratories and delicate experiments. But modern technology increasingly relies on quantum mechanics for its basic operation, and the importance of quantum effects will only grow in the decades to come. As such, physicist Miguel F. Morales has taken on the herculean task of explaining quantum mechanics to the rest of us laymen in this seven-part series (no math, we promise). Below is the fourth story in the series, but you can always find the starting story plus a landing page for the entire series thus far on site.

Beautiful telescopic images of our Universe are often associated with the stately, classical physics of Newton. While quantum mechanics dominates the microscopic world of atoms and quarks, the motions of planets and galaxies follow the majestic clockwork of classical physics.

But there is no natural limit to the size of quantum effects. If we look closely at the images produced by telescopes, we see the fingerprints of quantum mechanics. That’s because particles of light must travel across the vast reaches of space in a wave-like way to make the beautiful images we enjoy.

This week we’ll concentrate on how photons travel across light years, and how their inherent quantum waviness enables modern telescopes, including interferometric telescopes the size of the Earth.

Starlight

How should we think about the light from a distant star? Last week we used the analogy of dropping a pebble into a lake, with the ring of ripples on the water standing in for the wave-like motion of photons. This analogy helped us understand the length of a particle ripple and how photons overlap and bunch together.

We can continue that analogy. Every star similar to the Sun, in that it makes a lot of photons. As opposed to someone carefully dropping single pebbles into a mirror-smooth lake, it’s more like they poured in a bucket of gravel. Each pebble makes a ring of ripples, and the ripples from each stone spread out as before. But now the ripples are constantly mixing and overlapping. As we watch the waves lap against Earth’s distant shore, we don’t see the ripples from each individual pebble; instead the combination of many individual ripples have added together.

Enlarge / The chaotic waves from a gravel star crossing our pond. The ripples of many pebbles overlap, creating a complex set of waves.

Miguel Morales

So let’s imagine we’re standing on the shore of a lake as the waves wash in, looking at our gravel ‘star’ with a telescope for water waves. The lens of the telescope focuses the waves from the star onto a spot: the place on the camera sensor where the light from that star lands.

If a second bucket of gravel is dropped into the lake farther along the opposite shore, the ripples will overlap at our shore, but will be focused by the telescope into two distinct spots on the detector. Similarly, a telescope can sort the light from the stars into two distinct groups—photons from star A and photons from star B.

But what if the stars are very close together? Most of the ‘stars’ we see at night are actually double stars—two suns so close together they appear as one bright pinprick of light. When they’re in distant galaxies, stars can be separated by light years yet look like a single spot in professional telescopes. We’d need a telescope that could somehow sort the photons produced by the different stars to resolve them. Similar things apply if we want to image features like sunspots or flares on the surface of a star.

To return to the lake, there is nothing special about the ripples made by different pebbles—the ripples from one pebble are indistinguishable from the ripples made by another. Our wave telescope does not care if the ripples came from different pebbles in one bucket or different buckets altogether—a ripple is a ripple. The question is how far apart must two pebbles be dropped for our telescope to distinguish that the ripples came from different locations?

Sometimes when you’re stumped, it’s best to take a slow walk along the beach. So we’ll have two friends sit on the far shore dropping pebbles, while we walk along our shore, looking at the waves and thinking deep thoughts. As we walk along the beach we see that the waves from our friends overlap everywhere, and that the waves come in randomly. There appears to be no pattern.

  • The waves from two gravel “stars.” The waves from each star are circular (see next panels), but combine in an apparent jumble. However, we notice that while the wave train at each location is chaotic, at locations close to each other on the beach, the wave trains are very similar. At locations far down the beach, we see a completely different wave train.


    Miguel Morales

  • The waves from just one star.


    Miguel Morales

  • The waves from the other star. The waves can be combined to produce the wave pattern seen in the first panel.


    Miguel Morales

But on closer inspection, we notice that spots on the beach very near each other see nearly identical waves. The waves are random in time, but locations on the beach a few paces apart see the same random train of waves. But if we look at waves hitting far down the beach, that wave train is completely different than the one hitting near us. Any two places on the beach that are close together will see nearly identical wave trains, but widely separated locations on the beach see different wave trains.

This makes sense if we think of the waves on the beach as being the combination of little ripples from hundreds of pebbles. At nearby locations on the beach, the ripples from the pebbles dropped by both friends add up in the same way. But farther along the beach, the ripples from one friend will have to travel farther, so the ripples add up in a different way, giving us a new wave train.

While we can no longer see the ripples of individual pebbles once they have combined into waves, we can pace off how far we need to walk to see a new wave train. And that tells us something about how the ripples are adding together.

We can confirm this by asking our two pebble-dropping friends to move closer together. When our friends are close together, we notice that we have to walk a long way along our beach to see the ripples add up in a different way. But when our friends are far apart, just a few steps on our beach will make the wave trains look different. By pacing off how far we need to walk before the waves look different, we can determine how far apart our pebble-dropping friends are.

Enlarge / Large and small telescopes looking at the same two stars. Because the waves appear different at the far edges of the large telescope, it can sort the waves into two sources. For the small telescope, the waves look the same across the lens, so it sees the two stars as a single unresolved source.

Miguel Morales

The same effect happens with photon waves, which can help us understand the resolution of a telescope. Looking at a distant binary star, if the light waves entering opposite edges of the telescope look different, then the telescope can sort the photons into two distinct groups—the photons from star A and the photons from star B. But if the light waves entering opposite edges of the telescope look the same, then the telescope can no longer sort the photons into two groups and the binary star will look like one spot to our telescope.

If you want to resolve nearby objects, the obvious thing to do is to make the diameter of the telescope bigger. The farther apart the edges of the telescope, the more close the stars can be and still be distinguished. Bigger telescopes have better resolution than small telescopes, and can separate the light from more closely spaced sources. This is one of the driving ideas behind building truly enormous 30 or even 100 meter diameter telescopes—the bigger the telescope, the better the resolution. (This is always true in space, and true on the ground with adaptive optics to correct for atmospheric distortions.)

For telescopes bigger really is better.

Read original article here

Science

635 million-year-old fossil is the oldest known land fungus

Leave a comment

The oldest evidence of land fungus may be a wee microfossil that’s 635 million years old, found in a cave in southern China.

Too small to be seen with the naked eye, this remarkable find pushes back the appearance of terrestrial fungus by about 240 million years to a period known as “snowball Earth” when the planet was locked in ice from 750 million to 580 million years ago. 

The presence of land fungus at this critical point may have helped Earth to transition from a frozen ice ball to a planet with a variety of ecosystems that could host diverse life-forms, scientists wrote in a new study. By breaking down minerals and organic matter and recycling nutrients into the atmosphere and ocean, ancient fungus could have played an important part in reshaping Earth’s geochemistry, creating more hospitable conditions that paved the way for terrestrial plants and animals to eventually emerge and thrive.

Related: Images: The oldest fossils on Earth

Scientists discovered the fossilized threadlike filaments — a trademark of fungus structures — in sedimentary rocks from China’s Doushantuo Formation in Guizhou Province, dating to the Ediacaran period (about 635 million to 541 million years ago). Identifying rocks that might contain microscopic fossils takes luck as well as skill, said study co-author Shuhai Xiao, a professor of geosciences with the Virginia Tech College of Science (VT) in Blacksburgh, Virginia.

“There’s an element of serendipity, but there’s also an element of experience and expectation. Having worked with microfossils, one knows what kind of rocks to look at,” Xiao told Live Science. For example, rocks must be fine-grained, because the fossils are so small. Color can also provide clues; organic carbon in microfossils can make fossil-bearing rocks look darker than rocks that don’t contain fossils.

“But it’s not error-proof; most times, we slice a rock, and we don’t find anything. There’s maybe a 10% success rate,” Xiao said.

Thinly sliced

To find the fossils, the study authors ground slices of rock thin enough for light to penetrate, measuring no more than 0.002 inches (50 micrometers) thick. Powerful microscopes revealed the fungus’s tiny tendrils, which were just a few micrometers in diameter — about 1/10 the width of a human hair. Under the microscopes, traces of organic carbon in the fossils were darker than the rock surrounding it. 

The researchers also used more advanced microscopy to examine the fossils and build digital copies of their structures. Luckily, many of those structures “were excellently preserved in three-dimensions,” lead study author Tian Gan, a doctoral candidate at the Chinese Academy of Sciences in Beijing and a visiting scholar at VT, told Live Science in an email.

Three-dimensional rendition of the fungus-like filamentous microfossils and associated spherical fossils. (Image credit: Tian Gan of Virginia Tech and Chinese Academy of Sciences)

Those branching filaments told the researchers that the fossils were biological in origin, rather than mineral. Though some types of bacteria also produce branches, the closest analogs for these types of filaments are fungal, and small spheres in the fossil “could be interpreted as fungal spores,” supporting the hypothesis that these microorganisms were a type of fungus, the scientists wrote.

Ancient life

Fossil evidence of the earliest organisms on Earth is exceptionally rare, but this microfossil and other recent finds are helping researchers to slowly piece together important clues about when life first appeared. 

The oldest evidence of marine fungus, described in 2019 from rocks found in Canada, dates to about a billion years ago; the oldest forest, described in 2020 from fossilized roots in upstate New York, is 386 million years old; and the oldest known animal — a bizarre, oval-shaped creature called Dickinsonia — is about 558 million years old (fossils that were once thought to represent older animals were recently attributed to ancient algae, Live Science reported in December 2020).

Fossilized structures from Canada that may have been built by microbes between 3.77 billion and 4.29 billion years ago represent one of the oldest possible examples of life on Earth. Other structures preserved in Greenland rock are also thought to have microbial origins, and are 3.7 billion years old. Yet another fossil from western Australia may contain microbes estimated to be 3.5 billion years old, though some scientists have argued that geothermal activity could have altered chemicals in the rock to make them resemble biological traces, Live Science previously reported.

Scientists first linked terrestrial fungus to the appearance of land plants, based on fossils from the Rhynie cherts in Scotland that preserve plants and fungi together and date to about 410 million years ago, Xiao said. In those fossils, “plants and fungi have already established some sort of ecological relationship,” he explained. 

However, fungus fossils that predated the earliest known plants previously hinted that terrestrial fungus appeared first, about 450 million years ago, “and now we extend that back to 635 million years ago,” Xiao said.

The findings were published online Jan. 28 in the journal Nature Communications.

Originally published on Live Science.

Read original article here

Science

What if temperature determined a baby’s sex?

Leave a comment

The series “Imaginary Earths” speculates what the world might be like if one key aspect of life changed, whether related to the planet or humanity.

The sex of humans is largely controlled by the X and Y sex chromosomes. However, in many reptiles and fish, sex is instead influenced by how warm or cool eggs are before hatching. What might life be like for humans if sex was likewise under the sway of temperature?

The fact it was even possible to control the sex of animals using heat or cold was first uncovered in the rainbow agama lizard in 1966 by French zoologist Madeline Charnier at the University of Dakar in Senegal. She found hatchlings from eggs incubated at lower temperatures were female, while those that developed at higher temperatures were male.

Since then, scientists have discovered other patterns of temperature-dependent sex determination. For instance, with the Hawaiian green sea turtle, females emerge if incubated above a certain temperature and males if below a certain temperature, and if temperatures in nests fluctuate between those extremes, a mix of males and females are seen, according to a 2020 study published in the journal Bionatura. In contrast, with the American alligator, females develop from extremes of hot and cold and males from intermediate temperatures. 

Related: What if humans had photosynthetic skin?

Temperature controls sex determination, in all crocodilians, most turtles, many fish, and some lizards, according to organismal biologist Karla Moeller at Arizona State University. Within a specific window of time during the embryonic development of these animals, heat or cold can influence the production of sex hormones, which in turn can sway a hatchling’s fate.

Moeller noted that one cause of temperature-dependent sex determination is an enzyme known as aromatase, which can convert male sex hormones to female sex hormones. In animals such as the red-eared slider turtle, heat during a specific developmental stage can increase levels of this enzyme, leading to more females.

Evolutionary mysteries

It remains uncertain exactly why these animals practice temperature-dependent sex determination, although a huge number of theories exist, Jennifer Graves, a geneticist at La Trobe University in Melbourne, Australia, told Live Science in a phone interview.

“Our best guess is that temperature-dependent sex determination originated because reptiles do not have parental care and the eggs are in close interaction with the environment,” Diego Cortez, a biologist at the National Autonomous University of Mexico in Mexico City, told Live Science in an email. “We also know that elevated incubation temperatures speed up the development of embryos. So, the sex that is linked to higher incubation temperatures will hatch earlier.” 

Because, among reptiles, hatching is often linked with the rainy season, when life flourishes, any hatchling that emerges early will likely get more food, Cortez said. “With more food, it will grow faster, and will have higher chances of surviving until it reaches maturity,” he said.

According to this idea, known as the survival-to-maturity hypothesis, “if for some reason it is better for a species to have larger females or larger males at maturity, then this sex will be linked to high incubation temperatures so it can hatch earlier during the season,” Cortez said. 

Another possibility is that temperature-dependent sex determination could give a way for mothers to control the sex of their offspring. Scientists have suggested that female alligators may choose cooler nests to have more female hatchlings, so when populations are low, “females can make their nests down near the water so more females hatch,” Graves said. In contrast, when populations have reached a stable level, females might choose warmer nests “so there are a lot more males, getting more male aggression and competition.” The next generation of females could then choose from the best males, Graves suggested.

Unlikely in humans?

All known species with temperature-dependent sex determination are both oviparous, or egg-layers, and cold-blooded, meaning their body temperatures change with that of their surroundings. However, humans are neither of those things.

Related: Why do animals hibernate?

As such, “temperature-dependent sex determination in humans is not very likely because you would need, at a minimum, two different body temperatures — one that would trigger female development and one that would trigger male development,” Cortez said. “But the human body is always at 37 degrees Celsius (98.6 degrees Fahrenheit).”

Still, if women could somehow experience a range of body temperatures, Cortez said he could imagine a way for temperature-dependent sex determination to happen in humans. He noted that some proteins that help regulate circadian rhythms in humans — our internal clocks — are also linked with temperature-dependent sex determination in reptiles. These proteins, known as CLK kinases, are found throughout the body, and can sense very small fluctuations in body temperature.

“It would not be impossible to think that if CLK kinases are involved in temperature-dependent sex determination in reptiles, where they sense large changes in incubation temperatures — usually between 3 and 7 degrees Celsius [5.4 to 12.6 degrees F] — that the system could be adapted to sense smaller temperatures changes that could, hypothetically speaking, be then linked to the embryo’s sex,” Cortez said.

For temperature-dependent sex determination to exist in humans, Graves suggested one possibility is that we somehow become poikilotherms — that is, unable to control our body temperature — much like the naked mole-rat. Another possibility is that instead of live births, we were to somehow lay eggs like a platypus, she added.

Controlling sex

So what might humanity look like if temperature could decide the sex of our offspring? The most important consequence would likely be that it would then be trivial for parents to decide their children’s sex, Graves said.

One big risk is the potential for a major imbalance between the sexes in a society.

“Many humans like to decide the sex of their kids,” Cortez said. “Sadly, in many places on this planet, the preferred sex would be males. So, if humans could decide the sex of their offspring using a non-complicated technique, like changing their body temperature during a specific week during pregnancy — incubation temperature would have to be changed only during the week when sex is determined — I’m confident this would create many societies biased towards men.”

That would be a problem.

“We know that excess of one specific sex in adult populations creates an unbalanced population that has been linked to increased violence, more sexual conflict because is not easy for one sex to get a partner, less parental care, and so on,” Cortez added. “So, in other words, a less harmonious society.”

One could imagine that governments might intervene to ensure that one sex was not too heavily favored. However, “we might then start to speculate what might happen if the choice of sex might not be up to parents — what forces might interest the state to skew the sex ratio one way or the other,” Graves said.

Originally published on Live Science.

Read original article here

Science

This Ammonite Was Fossilized Outside Its Shell

Leave a comment

If anxious humans have nightmares of being naked in public, an anxious ammonite may have dreamed about swimming around without its shell, its soft body exposed to the elements and the leering eyes of predators.

For one unfortunate ammonite in the Late Jurassic, this was no dream but a harsh reality. The animal died utterly unclad, outside its whorled shell, and was buried this way. According to a study published recently in the Swiss Journal of Palaeontology, the ammonite’s death made it an extraordinary fossil — one of very few records of soft tissue in a creature that is most often immortalized as a shell.

“We know millions and millions of ammonites that have been preserved from their shell, so something exceptional had to happen here,” said Thomas Clements, a paleobiologist at the University of Birmingham in England who was not involved with the research. “It’s like finding ——” Dr. Clements said, trailing off. “Well, I don’t even know what it’s like finding, it’s that bizarre.”

René Hoffmann, an ammonitologist at the Ruhr-University Bochum in Germany who reviewed the study, called the fossil a “paleontological jackpot you have only once in a lifetime.”

To the untrained eye, the fossil looks more like an Impressionist painting than an ammonite: a pink, bean-shape smear surrounded by bulges, veins and ovals. It was discovered in the Solnhofen-Eichstätt region of southern Germany which was, in the ammonite’s day, around 150 million years ago, an archipelago studded with serene, oxygen-deprived lagoons. These conditions allowed soft, dead creatures to sink into the mud unscathed by predators or bacteria, according to Christian Klug, a paleontologist at the University of Zurich in Switzerland and the first author of the paper.

When Dr. Klug first saw the fossil, he knew it represented the soft parts of an ammonite, but exactly which soft parts, he did not know. He left it alone for months until Helmut Tischlinger, a fossil collector and an author on the paper, sent him photos of the fossil taken with ultraviolet light, which revealed the minute elevations and mineral stainings in the fossil.

Dr. Klug reconstructed the creature’s anatomy sequentially, from the most visible organs to the most obscure. First he identified the aptychus, a shelly lower jaw that indicated the fossil was an ammonite. Behind the jaws, he found the chitinous layer of the esophagus, and then a lump that suggested a digestive tract with a cololite — fecal matter (he used a different word) “that is still within the intestine,” Dr. Klug clarified.

“For the most part, the soft body reconstruction makes perfect sense,” said Margaret Yacobucci, a paleobiologist at Bowling Green State University in Ohio who was not involved with the research.

Solving the fossil’s other mystery — how the ammonite came to be separated from its shell — was far more difficult. The soft parts were so intact that they appeared to still be coiled. The authors propose several alternate endings to the ammonite’s life, each possible but uncertain. One suggests that the soft parts of a dead ammonite slipped out when the tissue connecting its body to its conch began to decay.

Another, more elaborate explanation imagines a predator breaking the ammonite’s shell from behind and sucking out its body only to drop the naked ammonite. “The best explanation is that some squid-like organism pulled out the soft parts and could not retrieve it,” Dr. Klug said.

Dr. Clements finds the clumsy predator theory “awesome” if unlikely; presumably a chomped-on ammonite body would show more visible damage. But he has no good alternative. Interpreting a fossil always invites some degree of doubt, and Dr. Clements predicts that the unarmed ammonite will be analyzed again in the future with robust chemical analyses.

Curiously, the fossilized ammonite is missing its arms, leaving unresolved one of the outstanding mysteries of ammonite anatomy. “Did they have many thin, delicate arms, like modern nautiluses, or a few strong arms, like modern coleoids?” Dr. Yacobucci asked. “If I gained access to a time machine, the very first thing I would do is zip back to the Jurassic to see what kind of arms ammonoids had.”

If a squid-like predator did in fact free the ammonite from its shell, it may have munched on the creature’s unknown quantity of arms as a consolation prize, nourishing both ancient cephalopods and the scientists who study them.

[Like the Science Times page on Facebook. | Sign up for the Science Times newsletter.]

Read original article here

Science

The ESA’s Solar Orbiter snaps unreal images of four planets at the same time

Leave a comment

We truly live on the cusp of a remarkable new era of space exploration, with SpaceX rockets rumbling almost every month and international probes spread out around the Milky Way capturing wondrous images of asteroids, comets, planets, moons, and our own shining Sun.

With all the activity and media coverage of these spacecraft and probes, it’s easy to become complacent or apathetic towards the data and photos their missions are delivering back to Earth. So let’s pause for a moment and gaze into the heavens at these dazzling new pics from NASA/ESA’s Solar Orbiter as it traverses our solar system studying our home star.

The new video footage below, pieced together with a series of photos, shows an incredibly rare cosmic tableaux of Earth, Mars, and Venus, with the faint light of Uranus also winking at us from beyond.

Video of Solar Orbiter snaps Venus, Earth and Mars

These inspiring images were obtained on November 18, 2020 by the SoloHI camera installed aboard Solar Orbiter. Venus (left), Earth (middle), and Mars (right) are clearly visible in the foreground, with a tapestry of bright stars in the background, all captured while the spacecraft loops around the Sun. Eagle-eyed astronomers also noted that Uranus shares the stage near the bottom edge.

“Solar Orbiter is the most complex scientific laboratory ever to have been built to study the Sun and the solar wind, taking images of our star from closer than any spacecraft before,” ESA researchers noted. “The Solar Orbiter Heliospheric Imager (SoloHI) is one of the six remote-sensing instruments onboard the mission. During the cruise phase, these are still being calibrated during specific periods, but are switched off otherwise.”

Venus, Earth, and Mars shift slightly in the SoloHI instrument’s field-of-view. Venus is the brightest object seen, hovering roughly 30 million miles away from the Solar Orbiter. When the shots were taken that day, the distance to Earth was 156 million miles and 206 million miles to Mars. Far off Uranus is a mere dot located beside the official time code.

“At the moment of the recording, Solar Orbiter was on its way to Venus for its first gravity assist flyby, which happened on December 27,” ESA scientists explained. “Venus and Earth flybys will bring the spacecraft closer to the Sun and tilt its orbit in order to observe our star from different perspectives.”

Read original article here

Science

Next SpaceX commercial crew mission to launch in April

Leave a comment

WASHINGTON — The second operational SpaceX commercial crew mission to the International Space Station will now launch in mid-April, carrying astronauts from Europe, Japan and the United States.

NASA said Jan. 29 that it set a launch date of April 20 for the Crew-2 mission to the station. NASA astronauts Shane Kimbrough and Megan McArthur will be the commander and pilor, respectively, with Japan Aerospace Exploration Agency astronaut Akihiko Hoshide and European Space Agency Thomas Pesquet on board as mission specialists.

The four will replace the Crew-1 astronauts who flew to the station in November on the first operational Crew Dragon mission. NASA astronauts Michael Hopkins, Victor Glover and Shannon Walker, and JAXA astronaut Soichi Noguchi, will return in that spacecraft in late April or early May, assuming Crew-2 launches on its current schedule.

NASA earlier announced a no-earlier-than launch date for Crew-2 of March 30. However, it delayed the mission to allow the uncrewed Orbital Flight Test 2 mission by Boeing’s CST-100 Starliner commercial crew vehicle to launch no earlier than March 25 for an approximately one-week mission. Both Starliner and Crew Dragon dock to one of two ports on the station, one of which is occupied by the Crew-1 Crew Dragon spacecraft.

The delay to April 20 also accommodates a Soyuz spacecraft, Soyuz MS-18, scheduled to launch around April 10. It will bring three Russian cosmonauts to the station, with Soyuz MS-17 returning to Earth a week later with Russian cosmonauts Sergey Ryzhikov and Sergey Kud-Sverchkov, and NASA astronaut Kate Rubins, on board.

“Around the mid-March timeframe we’ll really start to ramp up our preparations for doing some visiting vehicle operations,” Kenny Todd, deputy manager of the ISS program at NASA, said during a Jan. 22 briefing about an upcoming series of spacewalks at the station.

At the briefing he didn’t give a schedule for those missions. “We are still working with our Russian colleagues as well as the Commercial Crew Program to firm up the schedules for the Soyuz 64S and Crew-2 flights,” he said in a Jan. 27 statement to SpaceNews, using the NASA designation for Soyuz MS-18. “Both flights are currently targeting spring 2021, but specific launch dates have yet to be finalized.”

Two of the Crew-1 astronauts, Hopkins and Glover, performed the first in a series of spacewalks Jan. 27, working on the exterior of the Columbus module to support the Bartolomeo external payload platform and to install a new communications antenna there. A second spacewalk on Feb. 1 will complete the installation of a new battery for the station’s power system.

Another pair of spacewalks is tentatively planned for late February or early March, Todd said at the briefing. Those would take place after the arrival of a Cygnus cargo spacecraft currently scheduled for launch Feb. 20.

Read original article here