Science

Mpox outbreak is an international health emergency, WHO declares

africa, CDC, health, Infectious disease, mpox, outbreak, Science, WHO / Kris Guyer / August 14, 2024

PHEIC —

The declaration is “the highest level of alarm under international health law.”

Beth Mole – Aug 14, 2024 9: 36 pm UTC

Enlarge / A negative stain electron micrograph of a mpox virus virion in human vesicular fluid.

The World Health Organization on Wednesday declared an international health emergency over a large and rapidly expanding outbreak of mpox that is spilling out of the Democratic Republic of the Congo.

It is the second time in about two years that mpox’s spread has spurred the WHO to declare a public health emergency of international concern (PHEIC), the highest level of alarm for the United Nations health agency. In July 2022, the WHO declared a PHEIC after mpox cases had spread across the globe, with the epicenter of the outbreak in Europe, primarily in men who have sex with men. The outbreak was caused by clade II mpox viruses, which, between the two mpox clades that exist, is the relatively mild one, causing far fewer deaths. As awareness, precautions, and vaccination increased, the outbreak subsided and was declared over in May 2023.

Unlike the 2022–2023 outbreak, the current mpox outbreak is driven by the clade II virus, the more dangerous version that causes more severe disease and more deaths. Also, while the clade I virus in the previous outbreak unexpectedly spread via sexual contact in adults, this clade II outbreak is spreading in more classic contact patterns, mostly through skin contact of household members and health care workers. A large proportion of those infected have been children.

To date, Democratic Republic of the Congo (DRC), where the virus is endemic, has reported more than 22,000 suspect mpox cases and more than 1,200 deaths since the start of January 2023. In recent months, the outbreak has spilled out into multiple neighboring countries, including Burundi, Central African Republic, Republic of the Congo, Rwanda, Kenya, and Uganda.

Earlier on Wednesday, the WHO convened an emergency committee to review the situation, in which experts from affected countries presented data to independent international experts. The committee concluded that the outbreak constituted a PHEIC, and WHO Director-General Dr. Tedros Adhanom Ghebreyesus followed their recommendation.

“The emergence of a new clade of mpox, its rapid spread in eastern DRC, and the reporting of cases in several neighboring countries are very worrying,” Tedros said in a statement announcing the PHEIC. “On top of outbreaks of other mpox clades in DRC and other countries in Africa, it’s clear that a coordinated international response is needed to stop these outbreaks and save lives.”

On Tuesday, the Africa Centers for Disease Control and Prevention declared a similar emergency. Africa CDC Director General Dr. Jean Kaseya said the declaration will “mobilize our institutions, our collective will, and our resources to act—swiftly and decisively. This empowers us to forge new partnerships, strengthen our health systems, educate our communities, and deliver life-saving interventions where they are needed most.”

For now, the US Centers for Disease Control and Prevention assess the risk to the US public to be “very low,” given that there is limited and no direct travel between the US and the epicenter of the outbreak. So far, no clade I cases have been detected outside of central and eastern Africa.

Mpox outbreak is an international health emergency, WHO declares Read More »

NASA shuts down asteroid-hunting telescope, but a better one is on the way

asteroids, jet propulsion laboratory, NASA, near earth object, NEOWISE, Science, Space / Rejus Almole / August 14, 2024

Prolific —

The NEOWISE spacecraft is on a course to fall out of orbit in the next few months.

Stephen Clark – Aug 14, 2024 8: 34 pm UTC

Artist's illustration of NASA's Wide-field Infrared Survey Explorer spacecraft. — Enlarge / Artist’s illustration of NASA’s Wide-field Infrared Survey Explorer spacecraft.

Last week, NASA decommissioned a nearly 15-year-old spacecraft that discovered 400 near-Earth asteroids and comets, closing an important chapter in the agency’s planetary defense program.

From its position in low-Earth orbit, the spacecraft’s infrared telescope scanned the entire sky 23 times and captured millions of images, initially searching for infrared emissions from galaxies, stars, and asteroids before focusing solely on objects within the Solar System.

Wising up to NEOs

The Wide-field Infrared Survey Explorer, or WISE, spacecraft launched in December 2009 on a mission originally designed to last seven months. After WISE completed checkouts and ended its primary all-sky astronomical survey, NASA put the spacecraft into hibernation in 2011 after its supply of frozen hydrogen coolant ran out, reducing the sensitivity of its infrared detectors. But astronomers saw that the telescope could still detect objects closer to Earth, and NASA reactivated the mission in 2013 for another decade of observations.

The reborn mission was known as NEOWISE (Near-Earth Object Wide-field Infrared Survey Explorer). Its purpose was to use the spacecraft’s infrared vision to detect faint asteroids and comets on trajectories that bring them close to Earth.

“We never thought it would last this long,” said Amy Mainzer, NEOWISE’s principal investigator from the University of Arizona and UCLA.

Ground controllers at NASA’s Jet Propulsion Laboratory in California sent the final command to the NEOWISE spacecraft on August 8. The spacecraft, currently at an altitude of about 217 miles (350 kilometers), is falling out of orbit as atmospheric drag slows it down. NASA expects the spacecraft will reenter the atmosphere and burn up before the end of this year, a few months earlier than expected, due to higher levels of solar activity, which causes expansion in the upper atmosphere. The satellite doesn’t have its own propulsion to boost itself into a higher orbit.

“The Sun’s just been incredibly quiet for many years now, but it’s picking back up, and it was the right time to let it go,” Mainzer told Ars.

Astronomers have used ground-based telescopes to discover most of the near-Earth objects detected so far. But there’s an advantage to using a space-based telescope, because Earth’s atmosphere absorbs most of the infrared energy coming from faint objects like asteroids.

With ground-based telescopes, astronomers are “predominantly seeing sunlight reflecting off the surfaces of the objects,” Mainzer said. NEOWISE measures thermal emissions from the asteroids, giving scientists information about their sizes. “We can actually get pretty good measurements of size with relatively few infrared measurements,” she said.

The telescope on NEOWISE was relatively modest in size, with a 16-inch (40-centimeter) primary mirror, more than 16 times smaller than the mirror on the James Webb Space Telescope. But its wide field of view allowed NEOWISE to scour the sky for infrared light sources, making it well-suited for studying large populations of objects. One of the mission’s most famous discoveries was a comet officially named C/2020 F3, more commonly known as Comet NEOWISE, which became visible to the naked eye in 2020. As the comet moved closer to Earth, large telescopes like Hubble were able to take a closer look.

“The NEOWISE mission has been an extraordinary success story as it helped us better understand our place in the universe by tracking asteroids and comets that could be hazardous for us on Earth,” said Nicola Fox, associate administrator of NASA’s science mission directorate.

What’s out there?

The original mission of WISE and the extended survey of NEOWISE combined to discover 366 near-Earth asteroids and 34 comets, according to the Center for Near-Earth Object Studies. Of these, 64 were classified as potentially hazardous asteroids, meaning they come within 4.65 million miles (7.48 million kilometers) of Earth and are at least 500 feet (140 meters) in diameter. These are the objects astronomers want to find and track in order to predict if they pose a risk of colliding with Earth.

There are roughly 2,400 known potentially hazardous asteroids, but there are more lurking out there. Another advantage of using space-based telescopes to search for these asteroids is that they can observe 24 hours a day, while telescopes on the ground are limited to nighttime surveys. Some hazardous asteroids, such as the house-sized object that exploded in the atmosphere over Chelyabinsk, Russia, in 2013, approach Earth from the direction of the Sun. A space telescope has a better chance of finding these kinds of asteroids.

WISE, and then the extended mission of NEOWISE, helped scientists estimate there are approximately 25,000 near-Earth objects.

“The objects (NEOWISE) did discover tended to be overwhelmingly just dark, [and] these are the objects that are much more likely to be missed by the ground-based telescopes,” Mainzer said. “So that, in turn, gives us a much better idea of how many are really out there.”

NASA shuts down asteroid-hunting telescope, but a better one is on the way Read More »

Scientists solved mysterious origin of Stonehenge’s Altar Stone: Scotland

Archaeology, Science, stonehenge / Rejus Almole / August 14, 2024

The Altar Stone at Stonehenge. — Enlarge / The Altar Stone at Stonehenge weighs roughly 6 tons and was probably transported by land—or possibly by sea.

English Heritage

The largest of the “bluestones” that comprise the inner circle at Stonehenge is known as the Altar Stone. Like its neighbors, scientists previously thought the stone had originated in western Wales and been transported some 125 miles to the famous monument that still stands on the Salisbury Plain in Wiltshire, England. But a new paper published in the journal Nature came to a different conclusion based on fresh analysis of its chemical composition: The Altar Stone actually hails from the very northeast corner of Scotland.

“Our analysis found specific mineral grains in the Altar Stone are mostly between 1,000 to 2,000 million years old, while other minerals are around 450 million years old,” said co-author Anthony Clarke, a graduate student at Curtin University in Australia, who grew up in Mynydd Preseli in Wales—origin of most of the bluestones—and first visited the monument when he was just a year old. “This provides a distinct chemical fingerprint suggesting the stone came from rocks in the Orcadian Basin, Scotland, at least 750 kilometers [450 miles] away from Stonehenge.”

As previously reported, Stonehenge consists of an outer circle of vertical sandstone slabs (sarsen stones), connected on top by horizontal lintel stones. There is also an inner ring of smaller bluestones and, within that ring, several free-standing trilithons (larger sarsens joined by one lintel). Radiocarbon dating indicates that the inner ring of bluestones was set in place between 2400 and 2200 BCE. But the standing arrangement of sarsen stones wasn’t erected until around 500 years after the bluestones.

No contemporary written records exist concerning the monument’s construction, and scholars have pondered its likely use and cultural significance for centuries. Stonehenge’s form (and maybe its purpose) changed several times over the centuries, and archaeologists are still trying to piece together the details of its story and the stories of the people who built it and gathered in its circles.

In 2019, Parker Pearson and several colleagues reported the results of their investigation into the quarry source for the bluestones. They found that the 42 bluestones came all the way from western Wales. Chemical analysis has even matched some of them to two particular quarries on the northern slopes of the Preseli Hills.

One quarry, an outcrop called Carn Goedog, seems to have supplied most of the bluish-gray, white-speckled dolerite at Stonehenge. And another outcrop in the valley below, Craig Rhos-y-felin, supplied most of the rhyolite. When another group of archaeologists studied the chemical isotope ratios in the cremated remains of people once buried beneath the bluestones, those researchers found that many of those people may have come from the same part of Wales between 3100 and 2400 BCE.

But the sarsen stones hail from much closer to home. Since the 1500s, most Stonehenge scholars have assumed the sarsen stones came from nearby Marlborough Downs, an area of round, grassy hills 25 to 30km (17 miles) north of Stonehenge, which has the largest concentration of sarsen in the UK. A 2020 study by University of Brighton archaeologist David Nash and colleagues confirmed that.

Enlarge / The arrangement of stones at Stonehenge, color-coded to show where they came from.

English Heritage/Curtin University

Fifty of the sarsens shared very similar chemical fingerprints, which means they probably all came from the same place, most likely one site in the southeastern Marlborough Downs: West Woods, about 25 km (16 miles) north of Stonehenge and just 3 km (2 miles) south of where most earlier studies had looked for Neolithic sarsen quarries. The other two surviving sarsens came from two different places, which archaeologists haven’t pinpointed yet.

Scientists solved mysterious origin of Stonehenge’s Altar Stone: Scotland Read More »

The fish with the genome 30 times larger than ours gets sequenced

Biology, evolution, Genetics, Genomics, lungfish, Science, tetrapods / Paul Patrick / August 14, 2024

Image of the front half of a fish, with a brown and cream pattern and long fins. — Enlarge / The African Lungfish, showing it’s thin, wispy fins.

When it was first discovered, the coelacanth caused a lot of excitement. It was a living example of a group of fish that was thought to only exist as fossils. And not just any group of fish. With their long, stalk-like fins, coelacanths and their kin are thought to include the ancestors of all vertebrates that aren’t fish—the tetrapods, or vertebrates with four limbs. Meaning, among a lot of other things, us.

Since then, however, evidence has piled up that we’re more closely related to lungfish, which live in freshwater and are found in Africa, Australia, and South America. But lungfish are a bit weird. The African and South American species have seen the limb-like fins of their ancestors reduced to thin, floppy strands. And getting some perspective on their evolutionary history has proven difficult because they have the largest genomes known in animals, with the South American lungfish genome containing over 90 billion base pairs. That’s 30 times the amount of DNA we have.

But new sequencing technology has made tackling that sort of challenge manageable, and an international collaboration has now completed the largest genome ever, one where all but one chromosome carry more DNA than is found in the human genome. The work points to a history where the South American lungfish has been adding 3 billion extra bases of DNA every 10 million years for the last 200 million years, all without adding a significant number of new genes. Instead, it seems to have lost the ability to keep junk DNA in check.

Going long

The work was enabled by a technology generically termed “long-read sequencing.” Most of the genomes that were completed were done using short reads, typically in the area of 100–200 base pairs long. The secret was to do enough sequencing that, on average, every base in the genome should be sequenced multiple times. Given that, a cleverly designed computer program could figure out where two bits of sequence overlapped and register that as a single, longer piece of sequence, repeating the process until the computer spit out long strings of contiguous bases.

The problem is that most non-microbial species have stretches of repeated sequence (think hundreds of copies of the bases G and A in a row) that were longer than a few hundred bases long—and nearly identical sequences that show up in multiple locations of the genome. These would be impossible to match to a unique location, and so the output of the genome assembly software would have lots of gaps of unknown length and sequence.

This creates extreme difficulty for genomes like that of the lungfish, which is filled with non-functional “junk” DNA, all of which is typically repetitive. The software tends to produce a genome that’s more gap than sequence.

Long-read technology gets around that by doing exactly what its name implies. Rather than being able to sequence fragments of 200 bases or so, it can generate sequences that are thousands of base pairs long, easily covering the entire repeat that would have otherwise created a gap. One early version of long-read technology involved stuffing long DNA molecules through pores and watching for different voltage changes across the pore as different bases passed through it. Another had a DNA copying enzyme make a duplicate of a long strand and watch for fluorescence changes as different bases were added. These early versions tended to be a bit error-prone but have since been improved, and several newer competing technologies are now on the market.

Back in 2021, researchers used this technology to complete the genome of the Australian lungfish—the one that maintains the limb-like fins of the ancestors that gave rise to tetrapods. Now they’re back with the genomes from African and South American species. These species seem to have gone their separate ways during the breakup of the supercontinent Gondwana, a process that started nearly 200 million years ago. And having the genomes of all three should give us some perspective on the features that are common to all lungfish species, and thus are more likely to have been shared with the distant ancestors that gave rise to tetrapods.

The fish with the genome 30 times larger than ours gets sequenced Read More »

NASA chief to scientists on budget cuts: “I feel your pain”

bill nelson, NASA, Science, Space / Paul Patrick / August 13, 2024

Nelson as Senator Administrator —

“I can’t go and print the dollars.”

Eric Berger – Aug 13, 2024 9: 32 pm UTC

Photo of Bill Nelson. — Enlarge / Administrator Bill Nelson delivering remarks and answering questions from the media at the OFT-2 prelaunch press conference.

Trevor Mahlmann

Ars Technica recently had the opportunity to speak with NASA Administrator Bill Nelson, who has now led the US space agency for more than three years. We spoke about budget issues, Artemis Program timelines, and NASA’s role as a soft power in global diplomacy. What follows is a very lightly edited transcript of the conversation between Senior Space Editor Eric Berger and Nelson.

Ars Technica: I wanted to start with NASA’s budget for next year. We’ve now seen the numbers from the House of Senate, and NASA is once again facing some cuts. And I’m just wondering, what are your big concerns as we get into the final budgeting process this fall?

Administrator Bill Nelson: Well, the big concern is that you can’t put 10 pounds of potatoes in a five-pound sack. When you get cut $4.7 billion over two years, and when $2 billion of that over two years is just in science, then you have to start making some hard choices. Now, I understand the reasons for the cuts. Had I still been a member of the Senate I would’ve voted for it simply because they were held hostage by a small group in the House to get what they wanted. Which was reduced appropriations in order to raise the artificial, statutory budget debt ceiling in order for the government not to go into default. That’s part of the legislative process. It’s part of the compromises that go on. It happened over a year ago, and it was called the Fiscal Responsibility Act. The price for doing that wasn’t cuts across the entire budget. Remember, two-thirds of the budget is entitlement programs like Social Security and Medicare, and it certainly wasn’t in defense. So, all the cuts came out of everything left over, including NASA. I’m hoping that we’re going to get a reprieve come fiscal year ’26 when we will not be in the budgetary constraints of the Fiscal Responsibility Act. But who knows? Because lo and behold, they’ve got another artificial debt ceiling they’re going to have to raise next January.

Ars: What would you say to scientists who are concerned about Chandra, the cancellation of Viper, and Mars Sample Return, who see the budget for Artemis Program holding steady or even going up? It seems to me those of us who lived through Constellation saw this unfolding 15 to 20 years ago. Is the same thing happening with Artemis, is science being cannibalized to pay for human exploration?

Nelson: My response to the scientists is, I feel your pain. But, when I am faced with $2 billion of cuts over two years just in Science, I can’t go and print the dollars. And so, we have to make hard choices. Now, let’s go through those ones that you mentioned. Mars Sample Return. This was getting way out of control. It was going up to $11 billion, and we weren’t even going to get a sample return until 2040. And that’s the decade that when we’re going to land astronauts on Mars. So, something had to be done.

I convinced the budget director, Shalanda Young (director of the US Office of Management and Budget), and she was a partner in this, that we need to get those samples back. And so we pulled the plug on it. We said, “We’re going to start over, and we’re going to go out to all the NASA centers and to private industry, and we’re going to solicit and give some incentive money for their studies. And those studies will come back in, and by the end of the year, we will make a decision.” I’m hopeful that we are going to find such creativity and fiscal discipline that we’re going to end up with a much cheaper Mars sample return that will come back in the mid-30s, instead of all the way to 2040. So, if that’s what happens, and every indication I get is we’re getting some really creative proposals, if that’s what happens, then it’s a win-win. It’s a win for the taxpayer clearly. It’s a win for NASA because we didn’t have the money to spend $11 billion on it.

So, that’s one example. Another one that you used is Viper. Viper was running 40 percent over budget. Now, there comes a limit, and when you have to take a $2 billion hit just to science, you have to make tough choices. And so, that decision was made. We’re still getting (to the Moon) with Intuitive Machines at the end of the year. We are getting a lander that is going to drill to see if there is water underneath the surface. Understand that Viper was a much bigger rover, and it was going to rove around, but it was also 40 percent over budget. And so, these are the choices that you have to make.

You mentioned Chandra. By the way, I think we’ve worked Chandra out. Although it’s not going to have the funding way up there at the top funding. What we have worked out is, we are going to from what we requested, which was $41 million, it’s going to be some amount in excess of that. Although there will be some layoffs, not nearly as many, and all of the science will be protected. There will not be any diminution of the science.

NASA chief to scientists on budget cuts: “I feel your pain” Read More »

Researchers figure out how to keep clocks on the Earth, Moon in sync

Science / Kris Guyer / August 13, 2024

Does anyone really know what time it is? —

A single standardized Earth/Moon time would aid communications, enable lunar GPS.

John Timmer – Aug 13, 2024 8: 28 pm UTC

Image of a full Moon behind a dark forest of fir trees. — Enlarge / Without adjustments for relativity, clocks here and on the Moon would rapidly diverge.

Timing is everything these days. Our communications and GPS networks all depend on keeping careful track of the precise timing of signals—including accounting for the effects of relativity. The deeper into a gravitational well you go, the slower time moves, and we’ve reached the point where we can detect differences in altitude of a single millimeter. Time literally flows faster at the altitude where GPS satellites are than it does for clocks situated on Earth’s surface. Complicating matters further, those satellites are moving at high velocities, an effect that slows things down.

It’s relatively easy to account for that on the Earth, where we’re dealing with a single set of adjustments that can be programmed into electronics that need to keep track of these things. But plans are in place to send a large array of hardware to the Moon, which has a considerably lower gravitational field (faster clocks!), which means that objects can stay in orbit despite moving more slowly (also faster clocks!).

It would be easy to set up an equivalent system to track time on the Moon, but that would inevitably see the clocks run out of sync with those on Earth—a serious problem for things like scientific observations. So, the International Astronomical Union has a resolution that calls for a “Lunar Celestial Reference System” and “Lunar Coordinate Time” to handle things there. On Monday, two researchers at the National institute of Standards and Technology, Neil Ashby and Bijunath Patla, did the math to show how this might work.

Keeping time

We’re getting ready to explore the Moon. If everything goes to plan, China and a US-led consortium will be sending multiple uncrewed missions, potentially leading to a permanent human presence. We’ll have an increasing set of hardware, and eventually facilities on the lunar surface. Tracking just a handful of items at once was sufficient for the Apollo missions, but future missions may need to land at precise locations, and possibly move among them. That makes the equivalent of a lunar GPS valuable, as NIST notes in its press release announcing the work.

All that could potentially be handled by an independent lunar positioning system, if we’re willing to accept it marching to its own temporal beat. But that will become a problem if we’re ultimately going to do things like perform astronomy from the Moon, as the precise timing of events will be critical. Allowing for two separate systems would also mean switching all the timekeeping systems on board craft as they travel between the two.

The theory behind how to handle creating a single system has all been worked out. But the practicality of doing so has been left as an exercise for future researchers. But, apparently, the future is now.

Ashby and Patla worked on developing a system where anything can be calculated in reference to the center of mass of the Earth/Moon system. Or, as they put it in the paper, their mathematical system “enables us to compare clock rates on the Moon and cislunar Lagrange points with respect to clocks on Earth by using a metric appropriate for a locally freely falling frame such as the center of mass of the Earth–Moon system in the Sun’s gravitational field.”

What does this look like? Well, a lot of deriving equations. The paper’s body has 55 of them, and there are another 67 in the appendices. So, a lot of the paper ends up looking like this.

Enlarge / A typical section of the paper describing how the new system was put together.

Ashby and Patla, 2024

Things get complicated because there are so many factors to consider. There are tidal effects from the Sun and other planets. Anything on the surface of the Earth or Moon is moving due to rotation; other objects are moving while in orbit. The gravitational influence on time will depend on where an object is located. So, there’s a lot to keep track of.

Future proof

Ashby and Patla don’t have to take everything into account in all circumstances. Some of these factors are so small they’ll only be detectable with an extremely high-precision clock. Others tend to cancel each other out. Still, using their system, they’re able to calculate that an object near the surface of the Moon will pick up an extra 56 microseconds every day, which is a problem in situations where we may be relying on measuring time with nanosecond precision.

And the researchers say that their approach, while focused on the Earth/Moon system, is still generalizable. Which means that it should be possible to modify it and create a frame of reference that would work on both Earth and anywhere else in the Solar System. Which, given the pace at which we’ve sent things beyond low-Earth orbit, is probably a healthy amount of future-proofing.

The Astronomical Journal, 2024. DOI: 10.3847/1538-3881/ad643a (About DOIs).

Researchers figure out how to keep clocks on the Earth, Moon in sync Read More »

Why cricket’s latest bowling technique is so effective against batters

aerodynamics, cricket game, fluid dynamics, Magnus effect, Physics, Science, sports science / Mike M. / August 13, 2024

Enlarge / Some cricket bowlers favor keeping the arm horizontal during delivery, the better to trick the batsmen.

Although the sport of cricket has been around for centuries in some form, the game strategy continues to evolve in the 21st century. Among the newer strategies employed by “bowlers”—the equivalent of the pitcher in baseball—is delivering the ball with the arm horizontally positioned close to the shoulder line, which has proven remarkably effective in “tricking” batsmen in their perception of the ball’s trajectory.

Scientists at Amity University Dubai in the United Arab Emirates were curious about the effectiveness of the approach, so they tested the aerodynamics of cricket balls in wind tunnel experiments. The team concluded that this style of bowling creates a high-speed spinning effect that shifts the ball’s trajectory mid-flight—an effect also seen in certain baseball pitches, according to a new paper published in the journal Physics of Fluids.

“The unique and unorthodox bowling styles demonstrated by cricketers have drawn significant attention, particularly emphasizing their proficiency with a new ball in early stages of a match,” said co-author Kizhakkelan Sudhakaran Siddharth, a mechanical engineer at Amity University Dubai. “Their bowling techniques frequently deceive batsmen, rendering these bowlers effective throughout all phases of a match in almost all formats of the game.”

As previously reported, any moving ball leaves a trail of air as it travels; the inevitable drag slows the ball down. The ball’s trajectory is affected by diameter and speed and by tiny irregularities on the surface. Baseballs, for example, are not completely smooth; they have stitching in a figure-eight pattern. Those stitches are bumpy enough to affect the airflow around the baseball as it’s thrown toward home plate. As a baseball moves, it creates a whirlpool of air around it, commonly known as the Magnus effect. The raised seams churn the air around the ball, creating high-pressure zones in various locations (depending on the pitch type) that can cause deviations in its trajectory.

Physicists have been enthusiastically studying baseballs since the 1940s, when Lyman Briggs became intrigued by whether a curveball actually curves. Initially, he enlisted the aid of the Washington Senators pitching staff at Griffith Stadium to measure the spin of a pitched ball; the idea was to determine how much the curve of a baseball depends on its spin and speed.

Briggs followed up with wind tunnel experiments at the National Bureau of Standards (now the National Institute of Standards and Technology) to make even more precise measurements since he could control most variables. He found that spin rather than speed was the key factor in causing a pitched ball to curve and that a curveball could dip up to 17.5 inches as it travels from the pitcher’s mound to home plate.

Enlarge / The first recorded photo of a cricket match taken on July 25, 1857, by Roger Fenton.

Public domain

In 2018, we reported on a Utah State University study to explain the fastball’s unexpected twist in experiments using Little League baseballs. The USU scientists fired the balls one by one through a smoke-filled chamber. Two red sensors detected the balls as they zoomed past, triggering lasers that acted as flashbulbs. They then used particle image velocimetry to calculate airflow at any given spot around the ball. Conclusion: It all comes down to spin speed, spin axis, and the orientation of the ball, and there is no meaningful aerodynamical difference between a two-seam fastball and a four-seam fastball.

In 2022, two physicists developed a laser-guided speed measurement system to measure the change in speed of a baseball mid-flight and then used that measurement to calculate the acceleration, the various forces acting on the ball, and the lift and drag. They suggested their approach could also be used for other ball sports like cricket and soccer.

Enlarge / The Armfield C15-15 Wake Survey Rake measured pressure downstream of the ball.

A.B. Faazil et al., 2024

Similarly, golf ball dimples reduce the drag flow by creating a turbulent boundary layer of air, while the ball’s spin generates lift by creating a higher air pressure area on the bottom of the ball than on the top. The surface patterns on volleyballs can also affect their trajectories. Conventional volleyballs have six panels, but more recent designs have eight panels, a hexagonal honeycomb pattern, or dimples. A 2019 study found that the surface panels on conventional volleyballs can give rise to unpredictable trajectories on float serves (which have no spin), and modifying the surface patterns could make for a more consistent flight.

From a physics standpoint, the float serve is similar to throwing a knuckleball in baseball, which is largely unaffected by the Magnus force because it has no spin. Its trajectory is determined entirely by how the seams affect the turbulent airflow around the baseball. The seams of a baseball can change the speed (velocity) of the air near the ball’s surface, speeding the ball up or slowing it down, depending on whether said seams are on the top or the bottom. The panels on conventional volleyballs have a similar effect.

Why cricket’s latest bowling technique is so effective against batters Read More »

I trust NASA’s safety culture this time around, and so should you

Science, Space / Rejus Almole / August 12, 2024

Through a cloud-washed blue sky above Launch Pad 39A, Space Shuttle <em>Columbia</em> hurtles toward space on mission STS-107. ” src=”https://cdn.arstechnica.net/wp-content/uploads/2016/01/16271647815_f0b8187e11_o-640×474.jpg”></img><figcaption>
<p>Through a cloud-washed blue sky above Launch Pad 39A, Space Shuttle <em>Columbia</em> hurtles toward space on mission STS-107. </p>
<p>NASA</p>
</figcaption></figure>
<p>My first real taste of space journalism came on the morning of February 1, 2003. An editor at the Houston Chronicle telephoned me at home on a Saturday morning and asked me to hurry to Johnson Space Center to help cover the loss of Space Shuttle <em>Columbia</em>.</p>
<p>At the time, I did not realize this tragedy would set the course for the rest of my professional life, that of thinking and writing about spaceflight. This would become the consuming passion of my career.</p>
<p>I’ve naturally been thinking a lot about <em>Columbia</em> in recent weeks. While the parallels between that Space Shuttle mission and the first crewed flight of Boeing’s Starliner spacecraft are not exact, there are similarities. Most significantly, after the Space Shuttle launched, there were questions about the safety of the vehicle’s return home due to foam striking the leading edge of the spacecraft’s wing.</p>
<p>Two decades later, there are many more questions, both in public and private, about the viability of Starliner’s propulsion system after irregularities during the vehicle’s flight to the space station in June. NASA officials made the wrong decision during the <em>Columbia</em> accident. So, facing another <a href=

I trust NASA’s safety culture this time around, and so should you Read More »

NASA is about to make its most important safety decision in nearly a generation

Boeing, commercial crew, Features, human spaceflight, NASA, Science, Space, starliner / Paul Patrick / August 12, 2024

Boeing's Starliner spacecraft, seen docked at the International Space Station through the window of a SpaceX Dragon spacecraft. — Enlarge / Boeing’s Starliner spacecraft, seen docked at the International Space Station through the window of a SpaceX Dragon spacecraft.

As soon as this week, NASA officials will make perhaps the agency’s most consequential safety decision in human spaceflight in 21 years.

NASA astronauts Butch Wilmore and Suni Williams are nearly 10 weeks into a test flight that was originally set to last a little more than one week. The two retired US Navy test pilots were the first people to fly into orbit on Boeing’s Starliner spacecraft when it launched on June 5. Now, NASA officials aren’t sure Starliner is safe enough to bring the astronauts home.

Three of the managers at the center of the pending decision, Ken Bowersox and Steve Stich from NASA and Boeing’s LeRoy Cain, either had key roles in the ill-fated final flight of Space Shuttle Columbia in 2003 or felt the consequences of the accident.

At that time, officials misjudged the risk. Seven astronauts died, and the Space Shuttle Columbia was destroyed as it reentered the atmosphere over Texas. Bowersox, Stich, and Cain weren’t the people making the call on the health of Columbia‘s heat shield in 2003, but they had front-row seats to the consequences.

Bowersox was an astronaut on the International Space Station when NASA lost Columbia. He and his crewmates were waiting to hitch a ride home on the next Space Shuttle mission, which was delayed two-and-a-half years in the wake of the Columbia accident. Instead, Bowersox’s crew came back to Earth later that year on a Russian Soyuz capsule. After retiring from the astronaut corps, Bowersox worked at SpaceX and is now the head of NASA’s spaceflight operations directorate.

Stich and Cain were NASA flight directors in 2003, and they remain well-respected in human spaceflight circles. Stich is now the manager of NASA’s commercial crew program, and Cain is now a Boeing employee and chair of the company’s Starliner mission director. For the ongoing Starliner mission, Bowersox, Stich, and Cain are in the decision-making chain.

All three joined NASA in the late 1980s, soon after the Challenger accident. They have seen NASA attempt to reshape its safety culture after both of NASA’s fatal Space Shuttle tragedies. After Challenger, NASA’s astronaut office had a more central role in safety decisions, and the agency made efforts to listen to dissent from engineers. Still, human flaws are inescapable, and NASA’s culture was unable to alleviate them during Columbia‘s last flight in 2003.

NASA knew launching a Space Shuttle in cold weather reduced the safety margin on its solid rocket boosters, which led to the Challenger accident. And shuttle managers knew foam routinely fell off the external fuel tank. In a near-miss, one of these foam fragments hit a shuttle booster but didn’t damage it, just two flights prior to Columbia‘s STS-107 mission.

“I have wondered if some in management roles today that were here when we lost Challenger and Columbia remember that in both of those tragedies, there were those that were not comfortable proceeding,” Milt Heflin, a retired NASA flight director who spent 47 years at the agency, wrote in an email to Ars. “Today, those memories are still around.”

“I suspect Stich and Cain are paying attention to the right stuff,” Heflin wrote.

The question facing NASA’s leadership today? Should the two astronauts return to Earth from the International Space Station in Boeing’s Starliner spacecraft, with its history of thruster failures and helium leaks, or should they come home on a SpaceX Dragon capsule?

Under normal conditions, the first option is the choice everyone at NASA would like to make. It would be least disruptive to operations at the space station and would potentially maintain a clearer future for Boeing’s Starliner program, which NASA would like to become operational for regular crew rotation flights to the station.

But some people at NASA aren’t convinced this is the right call. Engineers still don’t fully understand why five of the Starliner spacecraft’s thrusters overheated and lost power as the capsule approached the space station for docking in June. Four of these five control jets are now back in action with near-normal performance, but managers would like to be sure the same thrusters—and maybe more—won’t fail again as Starliner departs the station and heads for reentry.

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520-million-year-old larva fossil reveals the origins of arthropods

Archeology, arthropods, Biology, evolution, Science / Rejus Almole / August 11, 2024

Loads of lobopods —

Early arthropod development illuminated by a microscopic fossil.

Elizabeth Rayne – Aug 11, 2024 11: 30 am UTC

Image of a small grey object, curved around its abdomen, with a series of small appendages on the bottom. — Enlarge / The fossil in question, oriented with its head to the left.

Yang Jie / Zhang Xiguang

Around half a billion years ago, in what is now the Yunnan Province of China, a tiny larva was trapped in mud. Hundreds of millions of years later, after the mud had long since become the black shales of the Yuan’shan formation, the larva surfaced again, a meticulously preserved time capsule that would unearth more about the evolution of arthropods.

Youti yuanshi is barely visible to the naked eye. Roughly the size of a poppy seed, it is preserved so well that its exoskeleton is almost completely intact, and even the outlines of what were once its internal organs can be seen through the lens of a microscope. Durham University researchers who examined it were able to see features of both ancient and modern arthropods. Some of these features told them how the simpler, more wormlike ancestors of living arthropods evolved into more complex organisms.

The research team also found that Y. yuanshi, which existed during the Cambrian Explosion (when most of the main animal groups started to appear on the fossil record), has certain features in common with extant arthropods, such as crabs, velvet worms, and tardigrades. “The deep evolutionary position of Youti yuanshi… illuminat[es] the internal anatomical changes that propelled the rise and diversification of [arthropods],” they said in a study recently published in Nature.

Inside out and outside in

While many fossils preserved in muddy environments like the Yuan’shan formation are flattened by compression, Y. yuanshi remained three-dimensional, making it easier to examine. So what exactly did this larva look like on the outside and inside?

The research team could immediately tell that Y. yuanshi was a lobopodian. Lobopodians are a group of extinct arthropods with long bodies and stubby legs, or lobopods. There is a pair of lobopods in the middle of each of its twenty segments, and these segments also get progressively shorter from the front to back of the body. Though soft tissue was not preserved, spherical outlines suggest an eye on each side of the head, though whether these were compound eyes is unknown. This creature had a stomodeum—the precursor to a mouth—but no anus. It would have had to both take in food and dispose of waste through its mouth.

Youti yuanshi has a cavity, known as the perivisceral cavity, that surrounds the outline of a tube that is thought to have once been the gut. The creature’s gut ends without an opening, which explains its lack of an anus. Inside each segment, there is a pair of voids toward the middle. The researchers think these are evidence of digestive glands, especially after comparing them to digestive glands in the fossils of other arthropods from the same era.

A ring around the mouth of the larva was once a circumoral nerve ring, which connected with nerves that extend to eyes and appendages in the first segment. Inside its head is a void that contained the brain. The shape of this empty chamber gives some insight into how the brain was structured. From what the researchers could see, the brain of Y. yuanshi had wedge-shaped frontal portion, and the rest of the brain was divided into two sections, as evidenced by the outline of a membrane in between them.

Way, way, way back then and now

Given its physical characteristics, the researchers think that Y. yuanshi displays features of both extinct and extant arthropods. Some are ancestral characteristics present in all arthropods, living and extinct. Others are ancestral characteristics that may have been present in extinct arthropods but are only present in some living arthropods.

Among the features present in all arthropods today is the protocerebrum; its evolutionary precursor was the circumoral nerve ring present in Y. yuanshi. The protocerebrum is the first segment of the arthropod brain, which controls the eyes and appendages, such as antennae in velvet worms and the mouthparts in tardigrades. Another feature of Y. yuanshi present in extant and extinct arthropods is its circulatory system, which is similar to that of modern arthropods, especially crustaceans.

Lobopods are a morphological feature of Y. yuanshi that are now found only in some arthropods—tardigrades and velvet worms. Many more species of lobopodians existed during the Cambrian. The lobopodians also had a distinctively structured circulatory system in their legs and other appendages, which is closest to that of velvet worms.

“The architecture of the nervous system informs the early configuration of the [arthropod] brain and its associated appendages and sensory organs, clarifying homologies across [arthropods],” the researchers said in the same study.

Yuti yuanshi is still holding on to some mysteries. They mostly have to do with the fact that it is a larva—what it looked like as an adult can only be guessed at, and it’s possible that this species developed compound eyes or flaps for swimming by the time it reached adulthood. Whether it is the larva of an already-known species of extinct lobopod is an open question. Maybe the answers are buried somewhere in the Yuan’shan shale.

Nature, 2024. DOI: 10.1038/s41586-024-07756-8

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China’s Long March 6A rocket is making a mess in low-Earth orbit

broadband, china, long march 6a, military space, Science, Space, space command, telecom / Mike M. / August 10, 2024

Another one —

After nearly every flight, the upper stage of this rocket breaks apart in orbit.

Stephen Clark – Aug 9, 2024 12: 41 pm UTC

Debris from the upper stage of China's Long March 6A rocket captured from the ground by Slingshot Aerospace. — Enlarge / Debris from the upper stage of China’s Long March 6A rocket captured from the ground by Slingshot Aerospace.

The upper stage from a Chinese rocket that launched a batch of Internet satellites Tuesday has broken apart in space, creating a debris field of at least 700 objects in one of the most heavily-trafficked zones in low-Earth orbit.

US Space Command, which tracks objects in orbit with a network of radars and optical sensors, confirmed the rocket breakup Thursday. Space Command initially said the event created more than 300 pieces of trackable debris. The military’s ground-based radars are capable of tracking objects larger than 10 centimeters (4 inches).

Later Thursday, LeoLabs, a commercial space situational awareness company, said its radars detected at least 700 objects attributed to the Chinese rocket. The number of debris fragments could rise to more than 900, LeoLabs said.

The culprit is the second stage of China’s Long March 6A rocket, which lifted off Tuesday with the first batch of 18 satellites for a planned Chinese megaconstellation that could eventually number thousands of spacecraft. The Long March 6A’s second stage apparently disintegrated after placing its payload of 18 satellites into a polar orbit.

Space Command said in a statement it has “observed no immediate threats” and “continues to conduct routine conjunction assessments to support the safety and sustainability of the space domain.” According to LeoLabs, radar data indicated the rocket broke apart at an altitude of 503 miles (810 kilometers) at approximately 4: 10 pm EDT (20: 10 UTC) on Tuesday, around 13-and-a-half hours after it lifted off from northern China.

At this altitude, it will take decades or centuries for the wispy effect of aerodynamic drag to pull the debris back into the atmosphere. As the objects drift lower, their orbits will cross paths with SpaceX’s Starlink Internet satellites, the International Space Station and other crew spacecraft, and thousands more pieces of orbital debris, putting commercial and government satellites at risk of collision.

A new debris field of nearly 1,000 objects would be a significant addition to the approximately 46,000 objects Space Command tracks in Earth orbit. According to statistics compiled by Jonathan McDowell, an astrophysicist who monitors global launch and spaceflight activity, this would rank in the top five of all debris-generation events since the dawn of the Space Age.

This rocket has a track record

The medium-class Long March 6A rocket has launched seven times since debuting in March 2022, and military and commercial satellite tracking organizations have reported several breakups of the rocket’s upper stage. In November 2022, a Long March 6A upper stage disintegrated in orbit, creating a debris field of more than 500 trackable objects, according to NASA’s Orbital Debris Program Office.

Commercial satellite tracking companies observed smaller debris fields following several other Long March 6A flights this year.

In its space environment statistics report, the European Space Agency says there have been more than 640 “breakups, explosions, collisions, or anomalous events resulting in fragmentation” in orbit. So these things happen frequently. But it’s not clear what makes the Long March 6A, which has a relatively short flight history, particularly vulnerable to creating debris.

A Long March 6A rocket launches the first 18 Internet satellites for China's Qianfan, or Thousand Sails, broadband network. — Enlarge / A Long March 6A rocket launches the first 18 Internet satellites for China’s Qianfan, or Thousand Sails, broadband network.

Most rockets operating today either reignite their engines to reenter the atmosphere after deploying their payloads, or if that’s not feasible, they “passivate” themselves to empty their propellant tanks and drain their batteries to reduce the risk of an explosion.

In a report last year, NASA’s Orbital Debris Program Office said the Long March 6A upper stage has a mass of about 5,800 kilograms (12,800 pounds) without kerosene and liquid oxygen propellants. It is powered by a single YF-115 engine.

The launch Tuesday began the deployment of China’s “Thousand Sails” Internet network, which will initially consist of 1,296 satellites, with the possibility to expand to more than 14,000 spacecraft. This will require numerous launches, some of which will presumably use the Long March 6A.

“If even a fraction of the launches needed to field this Chinese megaconstellation generate as much debris as this first launch, the result would be a notable addition to the space debris population in LEO (low-Earth orbit),” said Audrey Schaffer, vice president of strategy and policy at Slingshot Aerospace, a commercial satellite tracking and analytics firm.

China has been responsible for several space debris incidents beyond the latest problems with the Long March 6A rocket. In 2007, China destroyed one of its own spacecraft in an anti-satellite missile test. This was the worst-ever instance of creating space debris, resulting in more than 3,000 trackable objects, and an estimate 150,000 or more smaller fragments.

On four occasions from 2020 through 2022, the massive core stage of China’s heavy-lift Long March 5B rocket has reentered the atmosphere in an uncontrolled manner, raising concerns that falling debris could put people and property at risk on Earth.

China plans more flights with its Long March 5B and Long March 6A rockets. China continued flying the Long March 5B rocket despite the risk it posed to people on the ground. Debris fields in orbit, however, don’t directly threaten any people on Earth, but they do raise the risk to satellites of all nations, including China’s own spacecraft.

“Events like this highlight the importance of adherence to existing space debris mitigation guidelines to reduce the creation of new space debris and underscore the need for robust space domain awareness capabilities to rapidly detect, track, and catalog newly-launched space objects so they can be screened for potential conjunctions,” Schaffer said in a statement.

This story was updated with the detection of additional debris fragments by LeoLabs.

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Rocket Report: Archimedes engine sees first light, New Glenn making moves

rocket report, Science, Space / Mike M. / August 10, 2024

All the news that’s fit to lift —

“Coming soon: a full recovery rehearsal with our landing vessel.”

Eric Berger – Aug 9, 2024 11: 00 am UTC

Enlarge / Rocket Lab says it fired up the Archimedes engine at full thrust this week.

Rocket Lab

Welcome to Edition 7.06 of the Rocket Report! There has been a lot of drama over the last week involving NASA, the crew of Starliner on board the International Space Station, and the launch of the Crew-9 mission on a Falcon 9 rocket. NASA is now down to a binary choice: Fly Butch Wilmore and Suni Williams home on Starliner, or send two astronauts to orbit on Crew-9, and return Wilmore and Williams next February on that spacecraft. We should know NASA’s final decision next week.

As always, we welcome reader submissions, and if you don’t want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets as well as a quick look ahead at the next three launches on the calendar.

Firefly inks another big Alpha contract. Firefly Aerospace said Wednesday that it has signed a multi-launch agreement with L3Harris Technologies for up to 20 launches on Firefly’s Alpha rocket, including two to four missions per year from 2027 to 2031, depending on customer needs. The new agreement is in addition to Firefly’s existing multi-launch agreement with L3Harris for three Alpha missions in 2026. What is not clear is exactly what satellites L3Harris wants to launch.

Putting skins on the wall … “Firefly continues to see growing demand for Alpha’s responsive small-lift services, and we’re committed to providing a dedicated launch option that takes our customers directly to their preferred orbits,” said Peter Schumacher, Interim CEO at Firefly Aerospace. This represents another significant win for the Alpha rocket, which can lift about 1 metric ton to low-Earth orbit. Under terms of a separate agreement announced in June, Lockheed purchased 15 launches from Firefly, with an option for 10 more, through the year 2029. (submitted by Ken the Bin and EllPeaTea)

Electron pushing launch cadence. Rocket Lab announced Wednesday that it has scheduled the launch for its 52nd Electron mission, which will deploy a single satellite for American space tech company Capella Space. The mission is scheduled to launch during a 14-day window that opens on August 11 from Rocket Lab Launch Complex 1 on New Zealand’s Mahia Peninsula.

Getting to ten much faster … Should this launch take place at the opening of this window, this Electron flight would occur just eight days after the most recent Electron mission on August 3. This upcoming mission for Capella will be Rocket Lab’s tenth mission for 2024, equaling the company’s annual launch record set in 2023. (submitted by Ken the Bin)

The easiest way to keep up with Eric Berger’s space reporting is to sign up for his newsletter, we’ll collect his stories in your inbox.

PLD Space to start work on launch site. PLD Space plans to start building launch facilities for its Miura 5 rocket in October from the Diamant site at Guiana Space Centre, cofounder and Chief Business Development Officer Raúl Verdú said this week, Space News reports. Diamant has been dormant for decades after once being used for the French rocket of the same name, and “in the area where we are there is nothing,” Verdú said, “we have to do everything from scratch.”

Lots of things to build … PLD Space, Germany’s Isar Aerospace and a handful of other small European launchers are working with France’s CNES space agency to convert the site into a multi-use facility. In June, the Spanish company announced a 10 million euro ($11 million) investment plan for 15,765 square meters of space at Diamant, divided between a launch zone and a preparation area comprising an integration hangar, clean room, control center, commercial and work offices. CNES is providing common infrastructure such as roads and electricity networks. (submitted by Ken the Bin)

Japanese firm raises $21 million. Interstellar Technologies announced a new fundraising round that brings its total capital and government funding to $117 million, Payload reports. After building and launching a suborbital rocket called Momo, the company is building its first orbital rocket, dubbed ZERO, with a goal of flying in 2025. This rocket is intended to carry 800 kg of payload to low-Earth orbit, and be cheaper than Rocket Lab’s Electron, COO Keiji Atsuta said.

Big help from Japan … Interstellar’s latest round was led by Japanese VC fund SBI and NTT Docomo, the country’s leading mobile firm. Previously, it received a large amount of funding, $96 million, from the Japanese government. “The Japanese government has explicitly expressed its support for private rockets due to the growing importance of the space industry, and being selected for this support program has significantly accelerated our business,” Interstellar CEO Takahiro Inagawa said. (submitted by Ken the Bin)

Cross-border deal benefits Nova Scotia spaceport. The Canadian government says it has completed negotiations with the United States on an agreement that would allow the use of US space launch technology, expertise, and data for space launches in Canada, the AP reports. Maritime Launch Services, the company developing Canada’s first commercial spaceport in northeastern Nova Scotia, called the agreement a major step forward for the industry.

US rockets could launch from Canada … Ottawa has said it hopes to position Canada as future leader in commercial space launches. The country has geographical advantages, including a vast, sparsely populated territory and high-inclination orbits. The agreement, which is yet to be signed, will establish the legal and technical safeguards needed while ensuring the proper handling of sensitive technology, the government said in a news release. (submitted by JoeyS-IVB)

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