Living with food allergies can be a fraught existence. There is no cure, and the standard management is to be ever vigilant of everything you eat and have an emergency shot of epinephrine constantly handy in case an accidental ingestion leads to a swift, life-threatening reaction. But, for the millions of people in the US who live with such allergies, a new drug may dull the threat.

On Friday, the Food and Drug Administration approved the antibody drug omalizumab (brand name Xolair) as an injection to lessen allergic reactions to foods in people ages 1 and up. In a trial of 168 children and adults with multiple food allergies, participants who received shots of omalizumab for 16 to 20 weeks were much more likely to tolerate a test dose of allergy-inducing foods at the end than those who received a placebo.

Omalizumab—which was previously approved to treat asthma, hives, and nasal polyps—works by binding to a class of antibodies in the body called immunoglobulin E (IgE) that are specifically involved in allergic responses. The monoclonal antibody drug binds IgE, blocking it from binding to its target receptor, thus preventing it from triggering the immune responses that lead to allergy symptoms.

"This newly approved use for Xolair will provide a treatment option to reduce the risk of harmful allergic reactions among certain patients with IgE-mediated food allergies," Kelly Stone, associate director of the Division of Pulmonology, Allergy, and Critical Care in the FDA’s Center for Drug Evaluation and Research, said in today's announcement. "While it will not eliminate food allergies or allow patients to consume food allergens freely, its repeated use will help reduce the health impact if accidental exposure occurs."

The trial began in 2019 and was run by the National Institute of Allergy and Infectious Diseases and is still ongoing. But an interim analysis of early data was enough to convince the FDA of the drug's benefit.

More tolerance

For the trial, researchers recruited people who had an allergy to peanuts, as well as at least two other food allergies, including milk, egg, wheat, cashew, hazelnut, or walnut. Those assigned to get omalizumab received shots every two to four weeks for 16 to 20 weeks. Afterward, researchers looked at whether participants could handle 600 milligrams or more of peanut protein, which is equivalent to eating about 2.5 or more peanuts. Of those who got the shot, 68 percent (75 of 110 subjects) handled the peanut doses without moderate to severe allergy symptoms, such as whole-body hives, persistent coughing, or vomiting. In the placebo group, only 6 percent (3 of 55 subjects) managed this.

As secondary tests, the researchers tried other allergy-triggering foods at the higher dose of 1,000 milligrams or more. For cashews, 42 percent (27 of 64) of participants who received omalizumab tolerated the challenge without moderate or severe allergic reactions, compared with 3 percent (1 of 30) in the placebo group. For milk, 66 percent (25 of 38 subjects) who received the drug tolerated the dairy, while only 11 percent (2 of 19) of the placebo group did so. For egg, 67 percent (31 of 46 subjects) on the drug tolerated the dose, compared to 0 percent of the 19 who received placebo.

The benefits of omalizumab were not universal. The FDA notes that 17 percent of the people who received the drug had no significant improvement in their sensitivity to allergy-triggering food. As such, the FDA cautions that even if people receive Xolair, they should still avoid the foods that trigger their allergies.

The trial is ongoing, and researchers plan to look at the longevity of the drug's effectiveness and whether it can be paired with another strategy to ratchet down food allergies: oral immunotherapy (OIT), which uses small, daily doses of an allergen to build tolerance over time. For the look at longevity, some trial participants will get shots for an additional 24 weeks, followed by more food challenges to see if the drug remains useful at easing allergic responses over the prolonged time period. For the OIT part of the trial, participants will get another 16 weeks of injections and, halfway through that, some will undergo multi-allergen OIT. They will then be followed for 44 additional weeks.

The FDA says the most common side effects of omalizumab are injection site reactions and fever, but the agency also warns of the possibility of joint pain, rash, parasitic infections, malignancies, and abnormal laboratory tests.

Welcome to Edition 6.31 of the Rocket Report! Photographers at Cape Canaveral, Florida, noticed a change to the spaceport's skyline this week. Blue Origin has erected a full-size simulator of its New Glenn rocket vertically on its launch pad for a series of fit checks and tests. Late last year, we reported Blue Origin was serious about getting the oft-delayed New Glenn rocket off the ground by the end of 2024. This is a good sign of progress toward that goal, but there's a long, long way to go. It was fun to watch preparations for the inaugural flights of a few other heavy-lift rockets in the last couple of years (Starship, SLS, and Vulcan). This year, it's New Glenn.

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.

Russia launches a classified satellite. On February 9, Russia launched its first orbital mission of the year with the liftoff of a Soyuz-2-1v rocket from the Plesetsk Cosmodrome in the far north of the country. The two-stage rocket delivered a classified satellite into orbit for the Russian military, Anatoly Zak of RussianSpaceWeb.com reports. In keeping with the Russian military's naming convention, the satellite is known simply as Kosmos 2575, and there's little indication about what it will do in space, except for one key fact.

But wait, there's more ... It turns out the launch of Kosmos 2575 occurred at exactly the same time of day as another Soyuz-2-1v rocket launched on December 27 with a Russian military satellite named Kosmos 2574. The newer spacecraft launched into the same orbital plane as Kosmos 2574, a strong indication that the two satellites have a shared mission. In recent years, Russia has tested rendezvous, proximity operations, and, at least in one instance, a projectile that would have applications for an anti-satellite weapon. You can be sure the US military and a global community of hobbyist satellite trackers will watch closely to see if these two satellites approach one another. If they do, they could continue technology demonstrations for an anti-satellite system. It's unclear if the recent revelations regarding US officials' concerns about Russian anti-satellite capabilities are related to these recent launches.

European startup testing methane-fueled rocket engine. Space transportation startup The Exploration Company has continued testing its methane-fueled Huracán engine, which will power an in-space and lunar transportation vehicle under development, European Spaceflight reports. Most recently, the Huracán engine completed another round of thrust chamber testing using liquid methane fuel as a coolant and tested a new thermal barrier coating. The methane/liquid oxygen engine is undergoing testing at a facility in Lampoldshausen, Germany, ahead of use on The Exploration Company's Nyx Moon spacecraft, a transfer vehicle designed for transportation to and from cislunar space and also capable of Moon landings. The Nyx Moon is an evolution of a transfer vehicle the European startup is developing to ferry satellites between different orbits around Earth.

Other uses for Huracán... The Exploration Company appears to be positioning itself not only as a builder and operator of orbital and lunar transfer vehicles but also as a propulsion supplier to other space companies. In 2022, The Exploration Company received funding for the Huracán engine from the French government. At the time, the company described the engine as serving the needs of “the upper stages of small launchers and those of orbital vehicles." (submitted by Ken the Bin)

SpaceX launches commercial Moon mission. A Falcon 9 rocket carrying a privately developed lunar lander launched from Kennedy Space Center in Florida early Thursday. The vehicle, built by a Houston-based company called Intuitive Machines, was the second US-made lunar lander to launch from Florida in a little more than a month. The renaissance in American lunar landers represents the vanguard of NASA's program to return humans to the Moon and establish a more permanent presence, Ars reports. The first mission by Intuitive Machines, called IM-1, has a chance to become the first US-built spacecraft to make a soft landing on the Moon since 1972. The IM-1 mission is part of NASA's Commercial Lunar Payload Services (CLPS) program, which has the aim of finding lower-cost transportation services to ferry experiments and payloads to the Moon.

Not trivial ... As if landing on the Moon wasn't enough of a challenge, the IM-1 lander, named Odysseus, uses a mixture of cryogenic liquid methane and liquid oxygen propellants rather than the room-temperature fuels used by all previous Moon landers. Intuitive Machines chose these propellants because they are significantly less toxic than hypergolic fuels, and they allow the small lander to have a more powerful engine that can get to the Moon in days rather than a month or longer. However, cryogenic fuels are more challenging to work with because they must be kept chilled, limiting the time they can be stored for usage. Because of this, the lander had to be fueled just a couple of hours before liftoff while it was already closed up inside the Falcon 9's payload fairing on the launch pad. SpaceX had to modify the Falcon 9's second stage to route propellant into the lander's tanks. The late fueling procedure was "not trivial," said Bill Gerstenmaier, SpaceX's vice president of build and flight reliability. (submitted by Ken the Bin)

Missile defense satellites deployed by Falcon 9. Two prototype satellites for the Missile Defense Agency and four missile-tracking satellites for the US Space Force rode a SpaceX Falcon 9 rocket into orbit Wednesday from Florida's Space Coast, Ars reports. These satellites are part of a new generation of spacecraft designed to track hypersonic missiles launched by China or Russia and perhaps emerging missile threats from Iran or North Korea, which are developing their own hypersonic weapons. Hypersonic missiles are smaller and more maneuverable than conventional ballistic missiles, meaning they can evade detection by the US military's legacy missile defense satellites.

Military exercises ahead ... The Missile Defense Agency and Space Force satellites use different types of sensors to detect and track missile flights. The reason military officials opted to launch them together is to allow all six satellites to participate in military exercises later this year, in which the Space Force satellites will initially detect a missile launch with wide-view sensors, then cue the more sensitive MDA satellites to precisely track the missile and develop a firing solution for an interceptor that could shoot the missile out of the sky. These spacecraft are the final prototypes for a future military constellation of hundreds of missile-tracking and data-relay satellites to provide a global hypersonic missile-tracking capability. (submitted by Ken the Bin)

300 and counting for Falcon 9. SpaceX's workhorse Falcon 9 rocket launched for the 300th time on Thursday, carrying another batch of Starlink Internet satellites into orbit from Vandenberg Space Force Base, California. This is a remarkable milestone for the Falcon 9, which has flown more than any other single type of US rocket in history. This launch was also notable in that it was SpaceX's third Falcon 9 flight in a little more than 23 hours, following back-to-back launches from Florida Wednesday night into Thursday morning. Those two launches are covered in the two entries above this one.

Rolling on and rolling by … Last year, we reported the SpaceX steamroller had shifted into a higher gear. SpaceX keeps finding higher gears for its steamroller, with the goal of flying more than 140 missions in 2024. Taking into account its launches since January 1, SpaceX is on pace for about 120 launches by the end of the year. Another way of looking at SpaceX's launch statistics is to measure how many flights the company has accomplished in the last 365 days. As of Thursday, that number is at 101. Oh, and SpaceX has racked up 281 successful missions in a row with the Falcon rocket family, dating back to a prelaunch explosion in 2016. That's nearly three times the longest streak of successful flights by any other rocket in history.

First flight-ready Ariane 6 on the way to Kourou. The stages that make up the central core of Europe’s new rocket, Ariane 6, have left mainland Europe and are heading toward Europe’s spaceport in French Guiana, according to the European Space Agency. Shipping across the Atlantic, the main stage and upper stage were loaded into the purpose-built hybrid sailing ship Canopée at the harbors of Bremen, Germany, and Le Havre, France. The vessel is due to arrive in Kourou, French Guiana, before the end of February, and the rocket components will be trucked to a hangar at the Guiana Space Center for prelaunch processing.

On track for June … The first flight of Europe's Ariane 6 rocket remains on schedule for no earlier than June 15. ESA officials set this schedule following a series of checkouts and demonstrations last year using a test version of the Ariane 6 on its launch pad in French Guiana. Once the flight-worthy Ariane 6 arrives in French Guiana, technicians will connect the core stage and upper stage horizontally, then transfer the rocket to its launch pad and raise it vertically. Once upright, two solid-fueled boosters will be installed, followed by the payload shroud, or nose cone, containing the test flight's satellite passengers. (submitted by Ken the Bin)

Starship fully stacked for third flight. Over the last week, SpaceX has rolled out the Super Heavy booster and Starship upper stage to their launch pad in South Texas. This is in preparation for the third full-scale test flight of Starship, which could happen as soon as early March. On Tuesday, teams lifted Starship on top of the Super Heavy booster to complete stacking of the nearly 400-foot-tall (121-meter) rocket. That was followed by countdown rehearsals and propellant loading tests later in the week. From a technical perspective, it appears as if SpaceX could be ready to launch Starship quite soon.

Pending approval … As with SpaceX's first two Starship test flights last year, the company will need to receive a commercial launch license from the Federal Aviation Administration before proceeding with the next launch. For this to happen, SpaceX must submit the results of its investigation into what happened on the second test flight in November. That test flight was largely successful, but the Super Heavy booster exploded as it began to maneuver toward a controlled splashdown in the Gulf of Mexico. Then Starship disintegrated in the final moments of its burn around seven minutes after liftoff, just before reaching its desired velocity. (submitted by Ken the Bin)

New Glenn makes an appearance. This week, Blue Origin raised a simulator for its New Glenn rocket vertically at Space Launch Complex-36, the company's launch pad at Cape Canaveral Space Force Station, Florida. This is a sign of progress for the long-delayed New Glenn rocket program, and we should be seeing many more signs of activity at Cape Canaveral in the coming weeks and months if Blue Origin is really on track to launch the first New Glenn by the end of the year. We believe this simulator was built to mimic the dimensions and weight of a New Glenn rocket, allowing workers to test the launch pad's transporter/erector and strongback.

A first … Blue Origin largely finished construction of the launch pad in Florida a couple of years ago, but this is the first time anything resembling a New Glenn rocket has been seen upright at the launch site. Photographer Max Evans from NASASpaceflight.com captured beautiful views of the New Glenn simulator from a boat just off the coast of Cape Canaveral. The real New Glenn will be a beauty.

ULA still riding high from “perfect” debut of Vulcan. Tory Bruno, United Launch Alliance’s CEO, says the successful inaugural flight of the company’s Vulcan rocket January 8 was “dead nominal” and provided Astrobotic’s Peregrine lunar lander with a “bullseye insertion” into its targeted highly elliptical orbit around Earth, Space News reports. Bruno heralded the outcome of the Vulcan launch as vindication for ULA’s technology and approach to rocket development, which contrasts with the iterative development strategy favored by companies like SpaceX. “You can fly, fail, fix; nothing wrong with it,” Bruno said. Instead, ULA followed a “rigorous design process” with an emphasis on ground testing and computer simulations. “That’s how this was done and my guys just did an outstanding job.”

There’s another way … It’s easy to see why Bruno sees ULA’s approach as a vindication. The Vulcan rocket did its job, and not many companies can say that about the debut flight of a brand-new launch vehicle. And Vulcan has a bright future, at least in the near- to mid-term, with numerous launch contracts with Amazon and the US military. SpaceX’s Starship rocket is the most obvious example of an iterative development, where engineers emphasize flight testing. Proponents of this strategy argue it ultimately results in quicker results, lower costs, and a rocket that is just as reliable as a vehicle developed using ULA’s approach. (submitted by Ken the Bin, EllPeaTea, and Jay500001)

Next three launches

February 17: H3 | VEP-4 | Tanegashima Space Center, Japan | 00:22 UTC

February 17: GSLV Mk.II | INSAT 3DS | Satish Dhawan Space Center, India | 12:05 UTC

February 18: Electron | ADRAS-J | Mahia Peninsula, New Zealand | 14:52 UTC

After years of speculation, NASA finally revealed on Thursday the totality of the asteroid sample returned from Bennu to Earth last fall: 4.29 ounces (121.6 grams).

To put that number into perspective, the total mass is only slightly more than one-half cup of sugar or a box of 100 paper clips. It's about the same mass as a small avocado, and you can't even smear it on toast.

So, in some sense, it's a pretty small sample. Especially when you consider the lengths to which NASA and its partners went to retrieve it. The space agency's Goddard Space Flight Center worked with the University of Arizona and Lockheed Martin to build the OSIRIS-REx spacecraft for $800 million. It launched in September 2016 on an Atlas V rocket, which cost an additional $183.5 million. And as it has traipsed across the inner Solar System and back, NASA has spent an additional $200 million on mission operations.

A tin of tuna

Putting that all together, NASA has invested $1.2 billion and the better part of a decade to retrieve a volume of asteroid dust that could fit—comfortably—within a small can of tuna.

But, as the saying goes, good things come in small packages. And small though the sample may be, it is 20 times greater than the amount of asteroid material previously returned to Earth by a pair of Japanese sample return missions. A little will go a long way as scientists study the organics and other materials in this asteroid dust to divine clues to the origin of life and conditions that existed at the dawn of our Solar System. You don't need handfuls of material to get a meaningful result from an electron microscope.

Moreover, the sample retrieval was double the minimum requirement for the mission, 60 grams. So, OSIRIS-REx can now definitively be labeled as an unqualified success.

Biding their time

The scientific community had to wait longer than expected to know how much material OSIRIS-REx brought back to Earth. As engineers and technicians at Johnson Space Center in Houston worked to open the sample container last October, they were stymied by two stubborn fasteners. Only after new tools were devised was the sample container finally opened to reveal the tiny treasure in January.

In the coming weeks, some Bennu material will be packaged and distributed for researchers to study. As part of the OSIRIS-REx mission, a cohort of more than 200 scientists around the world will explore the regolith’s properties, including researchers from many US institutions, the Japan Aerospace Exploration Agency, and the Canadian Space Agency.

NASA, however, intends to reserve about 70 percent of the material for future study.

Almost half of all people in the world today speak an Indo-European language, one whose origins go back thousands of years to a single mother tongue. Languages as different as English, Russian, Hindustani, Latin, and Sanskrit can all be traced back to this ancestral language.

Over the last couple of hundred years, linguists have figured out a lot about that first Indo-European language, including many of the words it used and some of the grammatical rules that governed it. Along the way, they’ve come up with theories about who its original speakers were, where and how they lived, and how their language spread so widely.

Most linguists think that those speakers were nomadic herders who lived on the steppes of Ukraine and western Russia about 6,000 years ago. Yet a minority put the origin 2,000 to 3,000 years before that, with a community of farmers in Anatolia, in the area of modern-day Turkey. Now a new analysis, using techniques borrowed from evolutionary biology, has come down in favor of the latter, albeit with an important later role for the steppes.

The computational technique used in the new analysis is hotly disputed among linguists. But its proponents say it promises to bring more quantitative rigor to the field, and could possibly push key dates further into the past, much as radiocarbon dating did in the field of archaeology.

“I think that linguistics might be in for a sort of equivalent of the radiocarbon revolution,” says Paul Heggarty, a historical linguist at the Pontificia Universidad Católica del Perú in Lima, and a coauthor of the new study; he described the computational approach in the 2021 Annual Review of Linguistics.

Revealing dead languages

To understand what’s going on, it helps to look at how the study of Indo-European languages developed.

During the 16th century, as travel and trade put Europeans in touch with more foreign languages, scholars became increasingly interested in how languages related to one another, and where they might have originated.

In the late 18th century, Sir William Jones, a British judge in India, noticed similarities in vocabulary and grammar in Sanskrit, Latin, and Greek that couldn’t have been coincidental.

Historical linguists have reconstructed much of the grammar and vocabulary of the ancestor to Indo-European languages, to the point where we can piece together what conversations might have sounded like. Turn on closed captions to see a translation of the reconstruction presented here.

For instance, the English word “father” is “pitar” in Sanskrit and is “pater” in Latin and Greek. “Brother” is “bhratar” in Sanskrit, “frater” in Latin. Although Jones wasn’t actually the first to notice the similarities, his pronouncement that there must be a common origin helped to spur on a movement to compare languages and trace their relationships.

A major advance came in 1882, when Jacob Grimm formulated what would later be called Grimm’s Law. Grimm is best known today as one half of the Brothers Grimm, who collected and published Grimm’s Fairy Tales. But in addition to being a folklorist, Jacob Grimm was also an important linguist.

Grimm showed that as languages developed, sounds changed in regular ways that could help make sense of how languages were related. For instance, the Indo-European word for “two” was “dwo.” But “dwo” was one of a number of words whose initial “d” changed to “t” as it passed into the common ancestor of English and German. Later, the “t” sound became “ts” in an ancestor to modern German. So the Indo-European word “dwo” became “two” in English and “zwei” (pronounced “tsvai”) in modern German. Other words starting with the “d” sound behaved similarly. Scholars discovered a lot of these sound shift patterns, each obeying different rules, as one language gave birth to another.

Together with these sound shifts, linguists also study how words are formed, such as the way that English adds an “s” to make a word plural. They also look at how words are arranged, such as the way that English puts subjects before verbs and verbs before objects. And, of course, they look at shared vocabulary. By comparing all these features of different languages, linguists are able to map how languages descended from one another, and to place them in family trees that show their relationships.

Today, linguists are in broad agreement on the basics of Indo-European language groupings and how they are related to one another. They agree that the original language, which they call Proto-Indo-European, split into 10 or 11 main branches, two of which are now extinct.

They also generally agree on where to put languages within the main branches. For instance, they know that the Italic branch gave us Latin, which itself developed into the Romance languages such as French, Spanish, and Italian. The Germanic branch developed into languages including German, Dutch, and English. And the Indo-Iranian branch resulted in languages like Hindi, Bengali, Persian, and Kurdish.

Ancestral lifestyles

By tracing changes in language backwards towards their sources, linguists have deduced many of the basic characteristics of the original Proto-Indo-European language, including some vocabulary, how words were formed and some idea of how they were pronounced. And many linguists think they have even found hints of how the first Proto-Indo-Europeans might have lived.

For example, the Proto-Indo-European language had a word for axle, two words for wheel, a word for harness-pole and a verb that meant “to transport by vehicle.” Archaeologists know that wheel and axle technology was invented about 6,000 years ago, which suggests that Proto-Indo-European can’t be any older than that. If it was older—in other words, if it had started to split into other languages before it had words for axles and harness-poles—then its daughter languages would have had to invent their own words for these things. The fact that they use the same words suggests that the split started after these technologies were developed.

Other words in the language suggest that the first Indo-European speakers were probably familiar with horses, cattle- and sheepherding, dairy, wool, honey, and mead. They seem to have had chiefs (the word “reg” gave us our English word “regal”) and may have been patriarchal (they had words for “in-laws” that applied only to the bride’s side of the family, suggesting that the husband’s family was considered primary).

Many linguists think the vocabulary paints a picture of pastoralists—nomadic herders—who used horses and wagons. Combined with genetic evidence that people dispersed rapidly out of the steppes into central Europe about 5,000 years ago, they conclude that Indo-European languages moved out of the steppes and spread with the pastoralists.

In 1987, though, the Cambridge archaeologist Colin Renfrew rejected a pastoralist origin for Indo-European. Renfrew reasoned that the dramatic spread of Indo-European languages must have required a bigger push than could be provided by contact with ragtag groups of nomadic herders. For a major shift in which a single language grew to dominate a region stretching from Ireland to India, Renfrew argued, you needed a more powerful force.

He found it in the spread of farming. Simply put, as people took up farming their population grew more quickly than that of their hunting and gathering neighbors. As farming expanded, the languages moved with it. Archaeological evidence shows that farming had begun moving out of Anatolia about 3,000 years earlier than the spread of pastoralists out of the steppe. So, Renfrew concluded, farmers were the real force behind the spread of Indo-European. By the time the pastoralists started migrating, the farmers they met were already speaking an Indo-European language.

Renfrew largely dismissed the linguistic reasoning that the steppe hypothesis was based on. The commonality of words for wheel, wagon-pole, and the like, he said, can be explained by parallel shifts in which different languages draw on the same base meaning when creating a new word.

For instance, the original meaning of the Proto-Indo-European word for wheel seems to have meant something like circle, or turn. Different languages might have inherited that basic meaning and drawn on it independently when creating their own words for wheel.

Likewise, if the word “thill” for wagon-pole had a more general meaning of stick or pole, it could have been adopted to mean wagon-pole by more than one language.

Searching for rigor

Arguments like these led a few linguists to try a more quantitative approach to reconstructing the history of Indo-European. For this, they borrowed a technique often used in biology to build evolutionary trees based on measurable traits. Their approach, called computational phylogenetics, treats languages as evolving systems, similar to biological organisms. But instead of tracing changes in DNA, as computational phylogenetics in biology does, the technique in linguistics traces words. Specifically, most analyses have looked at patterns in words that mean the same thing in different languages, and that can be traced back to the same Proto-Indo-European root. The more similar those patterns are, the more closely related languages are generally thought to be.

While this may sound like the language trees long used by linguists, the trees produced by computational phylogenetics are far less subjective: The method is governed by strict algorithms and explicitly stated rules.

In essence, the computer program works by drawing a language tree and estimating the probability that it is correct given all the data and assumptions. Then the program makes a single change to that tree and compares the probability scores, keeping whichever tree is more probable. The process is repeated, sometimes millions of times, resulting in a set of most-probable trees.

These trees show how closely related languages are to one another. To estimate timings—when languages originated and diverged from one another—the researchers also provide the computer program with dates for when they think different languages existed, based on the best estimates of experts. Latin, for instance, existed around 2,050 years ago, Old Icelandic about 800 years ago, and Mycenaean Greek about 3,350 years ago. The computer program uses these anchor dates to create its timing estimates, including a date for the ultimate origin of Indo-European.

The results can be combined with the historical record of where languages were spoken to help figure out a likely map of how they spread geographically. And the dates can be combined with the archaeological record and studies of ancient human DNA to see if the Indo-European language lines up with an early farming origin, or a later steppe origin.

Contradictory results

One such analysis, published in 2012, pointed to an origin of Indo-European about 9,000 years ago in Anatolia, supporting the theory that Indo-European originated with farmers. But just three years later, a different team used much the same data to conclude that the origin was just 6,000 years ago on the steppes, supporting the opposite view that pastoralists were the first Indo-European speakers. How could the two teams reach such different conclusions from such a similar list of words?

Heggarty delved into the problem and discovered that the issue lay with the dataset used for both of these earlier analyses, which was largely based on one originally put together in the 1960s by Isidore Dyen, a linguist at Yale University. Dyen’s dataset had not been a problem for the research Dyen was doing, but when used for the new computational technique, it was throwing off the findings. Computational phylogeny works best when there is a single word for every root meaning researchers are interested in tracing. But the meaning “dirty,” for instance, can have a number of synonyms in English, including “filthy” and “unclean.” The Dyen dataset included synonyms like these for some words in some languages, but not for others.

Including any synonyms at all, Heggarty realized, made the dataset harder for the new computational technique to use. But having an inconsistent number of synonyms—more for some languages, fewer for others—really threw the calculations off. “I said, ‘Look, we have got to do this database completely again, from scratch. We have got to do much better,’” Heggarty says.

So he and his colleagues chose 170 core meanings they wanted to trace—basic words you would expect languages to preserve, such as words for counting numbers, body parts, colors, and things like house, mountain, laugh, and night. Then they brought together a team of more than 80 linguists and had them determine, for each of 161 Indo-European languages, the primary word for each concept. Only that word, and none of the synonyms, went into the analysis.

“We made a highly consistent database out of it, in a way that nobody has ever done before,” Heggarty says. “And we did a lot of analysis to make sure we chose the most appropriate meanings. If you don’t do your due diligence, your results won’t be valid.”

When Heggarty’s team reran the analysis with this new database, their findings broadly agreed with the earlier, farmer-origin theory, locating the origin squarely in Anatolia about 8,000 years ago. From there, some branches of the language moved eastward and gave rise to languages including Persian and Hindustani. Other branches moved west to eventually develop into Greek and Albanian.

But the analysis also recognizes the steppes as playing an important role as a secondary homeland for most European languages: After one branch traveled northward from Anatolia to the steppes, it radiated from there into northern Europe, giving birth to Germanic, Italic, Gaelic, and other European language families.

Not convinced

Mainstream historical linguists remain skeptical, however—of computational phylogenetics in general and the new result in particular. The main criticism is that the approach relies mostly on vocabulary and ignores word sounds and structures, such as the stems, prefixes, and suffixes that make up a word. And the critics say that word meanings by themselves don’t give enough information to draw firm conclusions, no matter how sophisticated the computation is.

Thomas Olander, a historical linguist at the University of Copenhagen, says that the problem with depending on related words is that languages borrow words from one another all the time. Just seeing that there are words in common between two languages, then, doesn’t mean the languages come from the same parent. The fact that English speakers now use the word “sushi,” for example, doesn’t mean that English and Japanese are related languages.

Instead, most linguists tend to trust sound shifts—such as the “dwo”—“two”—“zwei” shift—along with similarities in the structures of words that can indicate which language they originated in. Word meanings can also be part of that mix, but they can’t do it alone, Olander says.

Heggarty’s tree has other problems, as well. For instance, it shows Celtic languages as being closely related to Germanic languages. But Olander says most historical linguists think Celtic languages are much more closely related to Italic languages.

“It’s something that, again, is surprising,” Olander says. “I think ‘surprising’ could be translated to ‘It probably means that  their method is wrong.’”

Olander thinks it is far more likely that Celtic and Germanic branches coexisted closely for a long time and loaned one another words. An analysis based solely on shared word meanings shows them as more closely related than they actually are, he says.

James Clackson, a linguist at Cambridge University, also finds the early date for Proto-Indo-European, and other details of the tree, unconvincing. But he thinks computational phylogenetics is worth pursuing. And if nothing else, he says, the most recent research created a very high-quality new dataset that will be important to historical linguists in general as they seek to solve many unsettled issues in their field.

In the meantime, advocates of computational phylogenetics are likely to continue to promote their methods and seek legitimacy from the wider discipline. Heggarty thinks that as mainstream linguists get more comfortable with the method and the high-quality data it uses, they may give it more of a hearing.

Clackson, for one, says he’s willing to be convinced. “It’s a developing field, and it’s worth keeping an eye on,” he says.

This article originally appeared in Knowable Magazine, a nonprofit publication dedicated to making scientific knowledge accessible to all. Sign up for Knowable Magazine’s newsletter.

Early in Earth's history, the heat left over from the collision that formed the Moon left its surface an ocean of magma. As it cooled, its crust was frequently shattered by massive impacts that dwarfed the one that did in the dinosaurs. Somewhere in between that and the onset of plate tectonics, it's thought that a distinct process caused parts of the crust to sink, while volcanism brought material to the surface that would later form the continental crust.

While we can model this period, we can't really search for evidence to back our models, since any of this early crust has been eroded or transformed by the plate tectonics that eventually ensued. However, a team of researchers is suggesting that there might be a way to see what this process looked like, and it doesn't involve a time machine. Instead, it involves studying the surface of Mars.

Lots of volcanoes

On Mars, plate tectonics never got going. So, while some areas of the planet have been transformed in a way that keeps us from studying the earliest periods of Mars' history—looking at you, Olympus Mons—scientific consensus is that nearly half of the planet's surface is over 3.6 billion years old. This provides the opportunity to study processes that occurred in the first half-billion or so years after Mars formed.

To do so, a small team of researchers focused on an area called the Eridania Basins, deep depressions in Mars' southern hemisphere that may once have been home to a lake three times the size of the Caspian Sea. The crust in the area holds the strongest signal of Mars' early magnetic field, suggesting it might have formed early in the planet's history when the field was stronger.

The researchers started by cataloging all of the volcanic features in the area; and there were a lot of them—dozens, if not hundreds. Most of these have analogs on Earth: volcanic shields and calderas, debris flows, and stratovolcanoes all make appearances. Some of the volcanic features have properties that suggest they formed while the area was under water, indicating that eruptions took place while the basin was filled by Eridania Lake.

On its own, finding all of these features would be striking. But measurements of the composition of the volcanic material indicate it's high in what are called felsic materials, meaning rocks like granite. This is in contrast to the basaltic lavas found elsewhere on Mars. "The diverse volcanism is associated with felsic volcanic compositions which are unlike any other suite of recognized deposits or volcanic region on Mars," the researchers write.

Before plates

Felsic material is less dense than basaltic rocks and is a major component of the continental plates currently found on Earth. Because of its low density, it's thought to have been preferentially erupted back to the surface early in Earth's history, driving the process that would ultimately build continents. This process may have involved multiple rounds of enrichment, with mixed material being drawn to the interior of the planet, and progressively less dense material erupted back, building the precursors of Earth's continents.

Plate tectonics on Earth hadn't started yet, though, so material had to be cycled into the interior from the surface via some other mechanism. Evidence of that mechanism has also been largely wiped out by subsequent geological activity.

But that hasn't been the case on Mars. The researchers highlight the deepest portions of the basin, where the crust has both subsided and thinned dramatically. They suggest that this is a case where the base of the crust pulled away from the surface and sank into the planet's interior. There's even a site where a single ridge seems to have been pushed upward as three surrounding basins sank.

While this terrain is considered some of the oldest on Mars, the researchers suggest that, with nearly half the planet hosting very old surface features, it's worth looking at other regions in detail as well. This will hopefully catch other instances of the processes seen here, allowing us a clearer picture of early crust development on rocky planets.

Nature Astronomy, 2024. DOI: 10.1038/s41550-023-02191-7  (About DOIs).

The Centers for Disease Control and Prevention is preparing to update its COVID-19 isolation guidance, moving from a minimum five-day isolation period to one that is solely determined by symptoms, according to a report from The Washington Post.

Currently, CDC isolation guidance states that people who test positive for COVID-19 should stay home for at least five days, at which point people can end their isolation as long as their symptoms are improving and they have been fever-free for 24 hours.

According to three unnamed officials who spoke with the Post, the CDC will update its guidance to remove the five-day minimum, recommending more simply that people can end their isolation any time after being fever-free for 24 hours without the aid of medication, as long as any other remaining symptoms are mild and improving. The change, which is expected to be released in April, would be the first to loosen the guidance since the end of 2021.

In an email to Ars, a CDC spokesperson did not confirm or deny the report, saying only that, "There are no updates to COVID guidelines to announce at this time. We will continue to make decisions based on the best evidence and science to keep communities healthy and safe."

The Post notes that the proposed update to the guidance matches updated guidance from California and Oregon, as well as other countries.

The officials who spoke with the outlet noted that the loosened guidelines reflect that most people in the US have developed some level of immunity to the pandemic coronavirus from prior infections and vaccinations.

A report earlier this month found that the 2023–2024 COVID-19 vaccine was about 54 percent effective at preventing symptomatic COVID-19 when compared against people who had not received the latest vaccine. However, the CDC estimates that only about 22 percent of adults have received the updated shot.

Currently, the CDC recommends that people wear a mask for 10 days after testing positive unless they have two negative tests 48 hours apart. The Post reported that it's unclear if the CDC will update its mask recommendation.

In 2021, Jacob Geersen, a geophysicist with the Leibniz Institute for Baltic Sea Research in the German port town of Warnemünde, took his students on a training exercise along the Baltic coast. They used a multibeam sonar system to map the seafloor about 6.2 miles (10 kilometers) offshore.  Analyzing the resulting images back in the lab, Geersen noticed a strange structure that did not seem like it would have occurred naturally.

Further investigation led to the conclusion that this was a manmade megastructure built some 11,000 years ago to channel reindeer herds as a hunting strategy. Dubbed the "Blinkerwall," it's quite possibly the oldest such megastructure yet discovered, according to a new paper published in the Proceedings of the National Academy of Sciences—although precisely dating these kinds of archaeological structures is notoriously challenging.

As previously reported, during the 1920s, aerial photographs revealed the presence of large kite-shaped stone wall mega-structures in deserts in Asia and the Middle East that most archaeologists believe were used to herd and trap wild animals. More than 6,000 of these "desert kites" have been identified as of 2018, although very few have been excavated. Last year, archaeologists found two stone engravings—one in Jordan, the other in Saudi Arabia—that they believe represent the oldest architectural plans for these desert kites.

However, these kinds of megastructures are almost unknown in Europe, according to Geersen et al., because they simply didn't survive the ensuing millennia. But the Baltic Sea basins, which incorporate the Bay of Mecklenburg where Geersen made his momentous discovery, are known to harbor a dense population of submerged archaeological sites that are remarkably well-preserved—like the Blinkerwall.

After they first spotted the underwater wall, Geeren enlisted several colleagues to lower a camera down to the structure. The images revealed a neat row of stones forming a wall under 1 meter (3.2 feet) in height. There are 10 large stones weighing several tons, spaced at intervals, and connected by more than 1,600 smaller stones (less than 100 kilograms or 220 pounds).  "Overall, the ten heaviest stones are all located within regions where the stonewall changes is strike direction," the authors wrote. The length of the wall is 971 meters (a little over half a mile).

They concluded that the wall didn't form through natural processes like a moving glacier or a tsunami, especially given the careful placement of the larger stones wherever the wall zigs or zags. It is more likely the structure is manmade and built over 10,000 years ago, although the lack of other archaeological evidence like stone tools or other artifacts makes dating the site difficult. They reasoned that before then, the region would have been covered in a sheet of ice. The immediate vicinity would have had plenty of stones laying about to build the Blinkerwall. Rising sea levels then submerged the structure until it was rediscovered in the 21st century. This would make the Blinkerwall among the oldest and largest Stone Age megastructures in Europe.

As for why the wall was built, Geeren et al. suggest that it was used as a desert kite similar to those found in Asia and the Middle East. There are usually two walls in a desert kite, forming a V shape, but the Blinkerwall happens to run along what was once a lake. Herding reindeer into the lake would have slowed the animals, making them easier to hunt. It's also possible that there is a second wall hidden underneath the sediment on the seafloor. “When you chase the animals, they follow these structures, they don’t attempt to jump over them,” Geersen told The Guardian. “The idea would be to create an artificial bottleneck with a second wall or with the lake shore.”

A similar submerged stone-walled drive lane, known as "Drop 45," is located in Lake Huron in the US; divers found various lithic artifacts around the drive lane, usually in circular spots that could have served as hunting blinds. The authors suggest that the larger blocks of the Blinkerwall could also have been hunting blinds, although further archaeological surveys will be needed to test this hypothesis.

“I think the case is well made for the wall as an artificial structure built to channel movements of migratory reindeer,” archaeologist Geoff Bailey of the University of York, who is not a co-author on the paper, told New Scientist. Vincent Gaffney of the University of Bradford concurred. "Such a find suggests that extensive prehistoric hunting landscapes may survive in a manner previously only seen in the Great Lakes,” he said. “This has very great implications for areas of the coastal shelves which were previously habitable.”

PNAS, 2024. DOI: 10.1073/pnas.2312008121 (About DOIs).

Humans are driving migratory animals—sea turtles, chimpanzees, lions and penguins, among dozens of other species—towards extinction, according to the most comprehensive assessment of migratory species ever carried out.

The State of the World’s Migratory Species, a first of its kind report compiled by conservation scientists under the auspices of the U.N. Environment Programme’s World Conservation Monitoring Centre, found population decline, a precursor to extinction, in nearly half of the roughly 1,200 species listed under the Convention on Migratory Species (CMS), a 1979 treaty aimed at conserving species that move across international borders.

The report’s findings dovetail with those of another authoritative U.N. assessment, the 2019 Global Assessment Report on Biodiversity and Ecosystem Services, that found around 1 million of Earth’s 8 million species are at risk of extinction due to human activity. Since the 1970s, global biodiversity, the variation of life on Earth, has declined by a whopping 70 percent.

Migratory species face unique and heightened risks because they rely on connectivity among multiple ecosystems spanning national borders and because their predictable migration patterns make them vulnerable to poachers. The State of the World’s Migratory Species, released Monday, found that one in five species on the CMS list is threatened with extinction—and for listed fish, that number is a stark 97 percent.

The report’s authors say the numbers could be even more dire because the CMS treaty, also known as the Bonn Convention, covers only about a quarter of the world’s known migratory species—mammals, birds, reptiles, fish and one insect (the monarch butterfly). To be listed on one of the treaty’s two appendices, the 133 state parties must agree on the listing, and the species must generally either be endangered or have an “unfavorable conservation status.”

The report found that an additional 399 migratory species not covered by the treaty, including carp fish, ground sharks and petrels, also have declining populations and would benefit from CMS treaty protections.

To compile the report, the authors reviewed scientific literature and performed novel analyses using data from sources including the IUCN Red List of Threatened Species, the Living Data Index, the World Database of Protected Areas and CMS technical reports.

Among those analyses was an assessment of key locations where migrations take place. Pinpointing those areas was no easy task. Each year, billions of wild animals embark on journeys across Earth’s land, waters and sky. From troops of mountain gorillas knuckle-walking across central Africa’s rainforests, to monarch butterflies fluttering thousands of miles from North America to Mexico, and giant manta rays winging their way through the oceans, these species travel short and long distances seeking out favorable living conditions, food and places to breed.

The researchers were able to identify 9,500 key locations for CMS species. A little over half of those areas lack protected status while other key locations have yet to be identified.

Amy Fraenkel, executive secretary of CMS, called the report’s findings “startling” and pointed to the myriad of ways that humans and non-human parts of nature depend on migratory species.

As they make their way around the planet, migratory species contribute to the complex web of life on Earth by distributing seeds and nutrients, pollinating plants and controlling other species’ populations. Their loss can change the entire ecology of the ecosystems they inhabit. They also provide human communities with sources of food and income, contribute to overall ecosystem health and provide spiritual and aesthetic value.

Fruit bats, for instance, pollinate flowers and disperse seeds, helping cashew, passionfruit, fig and other fruit and nut trees reproduce. The Andean condor has cultural and spiritual significance for many Indigenous peoples and helps eliminate animal carrion, reducing the risk of disease. And a range of iconic animals like the African elephant and jaguar draw tourists hoping to catch a glimpse of their splendor, supporting local economies.

The report, like other authoritative assessments on Earth’s biodiversity, is unequivocal about what is driving the mass loss of life: the activities of just one species—humans.

Root causes of population decline

Unsustainable human activities threaten migratory species in a myriad of ways. By far, the two greatest pressures come from habitat loss and overexploitation, report co-author Kelly Malsch said.

Habitat loss, largely driven by land use change for agriculture, is degrading and fragmenting the ecosystems that are fundamental for migratory species survival, affecting three-fourths of all CMS species. Mountain gorillas, for example, have lost portions of their habitat to deforestation caused by the expansion of agriculture.

Overexploitation from hunting, fishing and incidental catch (the unintentional taking during fishing operations) affects seven out of ten CMS species, like the gray-headed albatross, birds whose population decline is largely attributed to their incidental capture in longline fisheries. Those and other entrapments in nets and lines cause immense amounts of suffering, raising serious ethical and animal welfare issues. Many CMS listed animals have complex social networks and high levels of intelligence.

Also driving the loss of migratory species is pollution from pesticides, plastics, heavy metals, light and noise, as well as the construction of roads, fences, dams and other infrastructure that creates physical barriers. With the human population surpassing 8 billion people in 2022 and a growing global economy, nearly a quarter of Earth’s surface is now affected by artificial lights, which disorient migrating animals and can cause life-ending collisions with human infrastructure.

Increasingly, all of these threats are amplified by human-induced climate change, which is itself a driver of migratory species loss. Rising temperatures, changes in precipitation, extreme weather, sea level rise and ocean acidification are outpacing species’ ability to adapt.

Animals’ migratory journeys are calibrated to coincide with optimal conditions for feeding and breeding. Warmer temperatures have snarled that synchronicity, causing some species to “arrive too early, too late or not at all,” the report said. In the case of Great Barrier Reef green turtles, rising temperatures have been linked to changing sex-determination, with an increasing number of new hatchlings born female. And in African wild dogs, extreme heat has been linkedto less foraging behavior and decreases in new pups.

Impacts on migratory species from climate change are expected to worsen in the coming decades. Last week, the European Union’s Copernicus Climate Change Service determined that the Earth’s average global temperature over the last 12 months had breached the critical 1.5 degree celsius threshold, portending grim prospects for certain species like narwhals, known as the unicorn of the sea for the long tusk protruding from their heads. Narwhals are highly sensitive to warming oceans. They depend on Arctic habitats where they feast on fish underneath sea ice. Warmer seas will impact the species’ ability to find sources of food, while growing ship traffic through melting Arctic areas will increase anthropogenic noise, disorienting narwhals and further harming their ability to forage for food.

Although the report features much devastation and bleak trends, the authors emphasize that further species declines and habitat destruction are not inevitable.

“There is hope if we act now to protect, connect and restore species populations and their habitats,” said Malsch, the head of Nature Conserved at the U.N. Environment Programme World Conservation Monitoring Centre.

Malsch pointed to the case of the humpback whale as a success story. The giant of the sea travels thousands of miles across all of Earth’s oceans. Thanks to a moratorium on commercial whaling, its population has rebounded to an estimated 80,000 globally, though subpopulations of humpbacks in the Arabian sea remain endangered.

The authors described a range of actions that can be taken to reverse the negative trends highlighted in the report: identifying additional key habitats, combating overexploitation, expanding conservation areas, restoring and maintaining connectivity between protected areas, and accounting for migratory species needs when building human infrastructure. Creation of protected areas, and their management, must respect the rights of Indigenous peoples and local communities, who have proven to be the best stewards of ecosystems, the report said.

Enforcement of the legally-binding CMS treaty is largely limited to the naming and shaming of violators through the treaty’s review mechanism. The United States is not a party to the treaty, but has signed onto non-binding Memorandums of Understanding developed under the auspices of the CMS.

Katie Surma is a reporter at Inside Climate News focusing on international environmental law and justice. Before joining ICN, she practiced law, specializing in commercial litigation. She also wrote for a number of publications and her stories have appeared in the Washington Post, USA Today, Chicago Tribune, Seattle Times and The Associated Press, among others. Katie has a master’s degree in investigative journalism from Arizona State University’s Walter Cronkite School of Journalism, an LLM in international rule of law and security from ASU’s Sandra Day O’Connor College of Law, a J.D. from Duquesne University, and was a History of Art and Architecture major at the University of Pittsburgh. Katie lives in Pittsburgh, Pennsylvania, with her husband, Jim Crowell.

This story originally appeared on Inside Climate News.

Establishing a precise time of death (the postmortem interval, or PMI) upon discovery of a corpse is notoriously challenging, however easy fictional medical examiners might make it seem. Some forensic scientists use the life cycle of blow flies, which seek out and lay eggs on corpses. But there’s a lot of variability between fly species and seasonal effects, so it would be helpful to develop new methods.

It turns out that studying the microbes that flourish in decomposing corpses can provide helpful clues. Forensic scientists have now identified some 20 microbes they believe constitute a kind of universal network driving the decomposition of dead animal flesh, according to a new paper published in the journal Nature Microbiology.

“One of the principal questions of any death investigation is ‘when did this person die?’” said Nancy La Vigne, director of the National Institute of Justice, which funded the research. “This continuing line of NIJ-funded research is showing promising results for predicting time of death of human remains, aiding in identification of the decedent, determining potential suspects, and confirmation or refutation of alibis.”

The work builds on nearly a decade's worth of prior research. For instance, in 2015, scientists were able to accurately estimate the time of death of mice and human corpses to within a two-to-four-day window, even after the bodies had decomposed for weeks. Earlier experiments had shown that, regardless of season, surroundings, and the species of the dead, communities of flesh-eating microbes seem to have a predictable timetable for when they dine on corpses. As Beth Mole reported for Ars at the time, "Those dining times relate to the stages of decomposition that a body undergoes—from fresh meat to bloated carcass, to rupturing and seeping nitrogen-rich fluids to actively decaying, then to an eventual dry state. Each stage attracts specific body-munching microbes, many with a taste for amino acids."

But the researchers weren’t sure if the microbes’ finely timed transition would look the same in different scenarios—such as carcasses in a desert versus in a forest, in the summer versus winter, or in corpses rotting peacefully versus those being picked at by scavengers. The 2015 experimental results showed that temperature determined the pace of the microbial dining schedule. But the schedule was remarkably similar between the four human bodies used in the experiment, as well as the mice, even given the outdoor exposure. So, the microbial munching pattern could be a universal clock for calling the time of death.

This latest paper extends the investigative scope to take a closer look at the specific kinds of microbes that tend to flourish in decomposing corpses. “When you’re talking about investigating death scenes, there are very few types of physical evidence you can guarantee will be present at every scene,” said co-author David Carter, a forensic scientist at forensic sciences at Chaminade University of Honolulu in Hawaii. “You never know if there will be fingerprints or bloodstains or camera footage. But the microbes will always be there.” In this latest study's case, “We’re talking about outdoor death scenes,” he added. “It can be difficult to gather information in those types of investigations.”

This time around, the team conducted outdoor experiments between 2016 and 2017 on 36 human cadavers at three different facilities (body farms😞 the Colorado Mesa University Forensic Investigation Research Station (FIRS), the Sam Houston State University Southeast Texas Applied Forensic Science (STAFS) Facility, and the University of Tennessee Anthropology Research Facility (ARF). Bodies were studied over 21 days during different seasons (spring, summer, fall, and winter). Daily samples were taken of both the grave soils associated with decomposition and skin from the head and torso of the bodies, as well as control soil samples. Daily temperature, humidity, and other environmental factors were also recorded.

The three facilities are located in two distinct climate types (temperate forest and semi-arid steppe), yet the team identified the same 20 decomposing microbes on all of the bodies, which once again showed up in predictable munching patterns regardless of outdoor variables. “It’s really cool that there are these microbes that always show up to decompose animal remains,” said co-author Jessica Metcalf of Colorado State University. “Hopefully, we’re busting open this whole new area of ecological research.”

These particular microbes aren't found in databases of microbes commonly found in soil, human skin, and gut microbiomes, so how do they find their way to tasty decomposing flesh? The authors suggest insects likely play a key role since these universal decomposer microbes are commonly found on insects like carrion beetles and blowflies.

The authors also used their new data in conjunction with machine learning to develop a predictive model for time of death based on microbial activity. The model performed remarkably well, predicting time of death within three calendar days in independent tests. The team attributes lingering errors to intrinsic factors like BMI/total body mass and extrinsic factors like scavengers and precipitation. These will be studied in future research to improve predictive models further.

Nature Microbiology, 2024. DOI: 10.1038/s41564-023-01580-y  (About DOIs).

MiMi Aung could barely contain her excitement as she drove up Oak Grove Drive, the leafy thoroughfare leading to NASA's Jet Propulsion Laboratory.

Aung had spent her formative years in Burma and Malaysia, two countries without a space program. A career in aerospace seemed beyond her reach. Yet here she was, at 22 years old, with a job interview to possibly work on the Deep Space Network. Aung dreamed of helping NASA intercept and amplify faint signals sent back to Earth from humanity's farthest-flung spacecraft, including the Voyagers.

"I remember it like it was yesterday," Aung said.

On that day in 1990, the math-loving engineer interviewed with prospective managers and visited facilities in the lab. It felt like home immediately. An energetic and enthusiastic person by nature, Aung spoke rapidly and asked a million questions. "You're like a kid in a candy store," one of the managers remarked. She was. Aung couldn't help herself. More than anywhere in the world, this is where she wanted to be.

She got the job. Over the next quarter of a century, Aung would work on the Deep Space Network and various other programs. Eventually, she became a manager, supervising the Guidance, Navigation & Control systems that help fly spacecraft.

In 2014, she was given a choice. Aung could remain as a manager—a plum position in the hierarchy at the Jet Propulsion Laboratory (JPL)—or take over a fledgling project to develop a small helicopter that might one day fly on Mars.

Aung made the leap. She and a small team dove into the technical details of an almost impossible engineering challenge due to the exceptionally thin air on the red planet. But even as the team made progress, a formidable array of adversaries lined up against the program intended to hitch a ride on the Perseverance rover to Mars in 2020.

Again and again, at JPL, in the upper floors of NASA's headquarters building in Washington, DC, and in the halls of Congress, these critics attempted to kill Ingenuity. And on multiple occasions, they almost succeeded.

This is the inside story of how Aung and a few champions of flying on Mars ultimately prevailed.

The origin of Ingenuity

The mad scientists at JPL had been dreaming of flying on Mars for a while. An engineer named Bob Balaram started toying with the idea in the 1990s, and he and a small team received a bit of money to put pen to paper on the concept. But before they could begin building anything, the funding dried up. The project was put on ice for more than a decade.

It received new life in 2013 when the longtime director of JPL, a Lebanon-born scientist and engineer named Charles Elachi, was touring the guidance and navigation division. The group had about 1,000 employees—one of whom, Aung, was its deputy manager. She was shepherding Elachi and a senior engineer at the lab, Rene Fredat, around. After visiting the drone lab, they boarded a small bus to move to the next stop.

"Why aren't you flying drones or helicopters on Mars?" Elachi asked Fredat.

Neither he nor Aung had a good answer. So Elachi provided a bit of seed funding to Balaram and a few others to update their calculations from the 1990s and determine whether the miniaturization revolution spurred by mobile phone technology would make flying on Mars—where a vehicle had to be exceedingly light but capable of rotating its blades at thousands of revolutions per minute—possible.  Aung was asked to support the project as a side job.

Eventually, it took more and more of her time. In September 2014, Aung had to decide whether to remain in a managerial role of a large division or take on the helicopter project. Even then, ill political winds were stirring around the idea, which would take away precious space on the Perseverance rover from scientific experiments.

"In hindsight, I realize how big of a thing that was to give up," she said of the senior managerial role at JPL. "But at the time, I didn't think twice about it. I felt like I had something to give."

It was her big chance, so she grabbed it.

Trying to kill it

A few months before Aung agreed to take over management of the Mars helicopter project, NASA announced the seven "carefully selected" payloads that would accompany the Mars 2020 rover, as it was then known, down to the surface of the red planet. The payloads had been selected from among 58 proposals.

"The Mars 2020 rover, with these new advanced scientific instruments, including those from our international partners, holds the promise to unlock more mysteries of Mars’ past as revealed in the geological record," said John Grunsfeld, the leader of NASA's Science Mission Directorate, at the time.

The helicopter was not among the seven payloads. Why? Because it would not serve to advance the scientific research that was to be done on Mars. Principally, the rover would search for evidence of past life. To the scientists, a technology demonstration such as a helicopter was, at best, a nuisance. At worst, it could imperil the overall mission.

"The science community just wasn't interested in Ingenuity," said Bobby Braun, an aerospace engineer who worked on the Mars Pathfinder mission in the 1990s and who had a career in academia and government service.

Although the helicopter was not selected to fly on the Mars 2020 rover, Elachi wouldn't take no for an answer. He enlisted a trusted lieutenant at JPL, Jakob van Zyl, to shepherd the program. They found some internal funding to keep the project going. After Aung agreed to lead the technical aspects of the project, van Zyl set about taking care of the programmatic side of things.

He would take up the political fight to get the helicopter on the rover. Aung had to make it work.

The helicopter loses a key ally

In the summer of 2016, the helicopter program was dealt a serious blow. Its champion, Elachi, retired at the age of 69. Having led JPL for 15 years, he wielded enormous influence. Elachi had also cultivated a deep friendship with a Texas Republican in Congress, John Culberson, who chaired the US House subcommittee that set NASA's budget.

The pair had kept the mission alive even though it didn't have an official berth on the Mars 2020 mission, which had not yet been named Perseverance. With Elachi out of the picture, van Zyl soon ran into troubled waters.

A few months after Elachi's retirement, NASA's science directorate got a new leader, a Swiss-American astrophysicist named Thomas Zurbuchen. He was immediately confronted by a number of concerns emanating from the California laboratory. The InSight lander, which had already been delayed from its planned 2016 launch, was at risk of missing a 2018 launch window. JPL also had upcoming deadlines for the Mars 2020 rover and Psyche spacecraft. Additionally, Culberson was pushing the lab to develop a $4 billion orbiter for the Jovian moon Europa.

"They were in over their heads," Zurbuchen said.

During his first week on the job, Zurbuchen met with two senior leaders at NASA: the agency's administrator, Charles Bolden, and its powerful associate administrator, Robert Lightfoot. Both urged him to kill the helicopter program. Bolden was taking his scientists' advice. Lightfoot also felt that JPL was overwhelmed with work and had no business distracting itself with the experimental helicopter.

The NASA leaders were not alone. Zurbuchen encountered two communities that were adamantly opposed to the helicopter. There were the Mars scientists who felt it was not right for a tech demo to take payload space on the rover and consume some of its time at the expense of the mission's real purpose of studying the planet's past habitability. And then there were the Mars 2020 mission managers.

"They were against it," Zurbuchen said. "They were just being good managers, by the way. That’s exactly the right answer. You should never distract yourself with things that are not necessary."

It would have been easy to axe the helicopter with Elachi gone. It would have been one less distraction for Zurbuchen, who had many fires to put out. He could have done it with a phone call.

“You’re not getting on the rover”

As he settled into his new job, Zurbuchen realized that Lightfoot was right—the Mars 2020 program was running significantly behind schedule to meet its launch date in July 2020. All of its scientific instruments, many of which JPL was assembling, were late. They were going to blow the budget.

A critical moment came in early 2017 when Zurbuchen visited JPL. There, he heard two presentations on possible add-ons to Mars 2020. One concerned a "drillable blank," which would essentially allow the mission managers to test whether the rover's drill bits were contaminated. Senior officials at this meeting advised Zurbuchen that this was a "high risk" technology.

Van Zyl, Aung, Balaram, and the rest of the helicopter team came next. At the time, they had only begun attempting to fly a small prototype of the helicopter in a chamber that simulated the atmosphere of Mars. As Zurbuchen listened to the presentation, he reflected on the fact that his leadership team at NASA headquarters was opposed to the mission. The rover's managers disliked it. And he wasn't sure the engineers giving the presentation fully understood the technical challenges they were up against.

Then the helicopter team made a claim that incensed Zurbuchen. Whereas the drillable blank team had characterized their plans as "high risk," the helicopter team said flying on Mars was "low risk." Zurbuchen's first reaction to this was do they really think I'm this stupid?

"You're bullshitting me," Zurbuchen told the helicopter team during the meeting.

Seven years later, he still gets a little worked up. "I told them that the first technology was a stone-age type of thing, drilling into the ground, and that was considered high risk," he recalled. "The second one is a drone in a place with a 1 percent pressure atmosphere. This was supposed to be low risk? I basically said, 'You’re not getting on the rover.'”

A way back

Zurbuchen had taken a hard line with the helicopter's team. But as an innovator, he wanted to find a way to get the experimental machine to Mars. As he got to know Aung and van Zyl, they earned his confidence. That "low-risk" assessment of the Mars helicopter? They had made it, basically, because JPL engineers had gotten away with that kind of assessment before, they explained.

Not this time. To fly on board Mars 2020, Zurbuchen said the team must overcome two major issues.

First, they had to deliver the machine. This meant flying the helicopter to prove it could actually work. And they had to deliver within a budget of $80 million, the amount Culberson had been able to scrounge up in Congress—enough money to support the program but not so much that it would draw attacks from other budget committee members.

Secondly, Zurbuchen said, the helicopter could not put the primary mission at risk. If it hitched a ride to Mars, the helicopter would be latched onto the bottom of Perseverance. This raised a potential issue because if the rover landed on a large enough rock, it could get stuck. Based on the Perseverance team's analysis, flying with the helicopter increased the risk. That is, with the helicopter tacked on, a smaller rock could trap the rover.

Another issue the rover team worried about was the deployment of the helicopter. What if it failed to detach? Perseverance could not really drive around the red planet with the helicopter slapping around under its belly. Because he didn't believe JPL could deliver on time, Zurbuchen farmed out the development of the deployment mechanism to Lockheed Martin. (The aerospace contractor delivered precisely what was needed on schedule and budget).

As he offered Aung and her team a pathway onto the rover, Zurbuchen continued hearing from influential figures in the NASA community that it was too risky. Among those calling was Tom Young, a former director of NASA's Goddard Space Flight Center and a highly respected engineer frequently counted upon to review NASA programs. An experimental tech demo like the helicopter, Young said, had no business flying on the agency's "Class A" missions. By design, such missions called for the maximum amount of risk reduction. These big missions could not fail. To do so would greatly embarrass NASA and threaten future funding.

Zurbuchen also conferred with allies like Culberson. He explained to the congressman that if the helicopter could not be safely delivered to Mars, it wasn't going. Culberson agreed that Ingenuity should not fly if it jeopardized the success of Perseverance. "He did not twist my arm," Zurbuchen said.

But elsewhere, Culberson was twisting arms.

Overcoming challenges

In a lengthy interview, Zurbuchen said Ingenuity never would have reached Mars but for Culberson's support. The conservative Congressman from Texas was both a devout Christian and a passionate supporter of space exploration. Critically for the Mars helicopter, Culberson's interests extended beyond the parochial politics of the field center in his Houston backyard, Johnson Space Center.

He frequently traveled across the country to visit the Jet Propulsion Laboratory, first with Elachi, and later with other directors. During these visits he was referred to as "Chairman" due to his perch on the House Appropriations subcommittee that managed NASA's budget. When Culberson first heard about the helicopter during one of his visits in the early 2010s, he was tickled by its potential and baffled by the opposition of NASA's leaders.

"I was thunderstruck when they told me they didn’t want to do it because it was too risky," he said in an interview. "That’s what NASA is for, brilliant engineering. I just wouldn’t let go. I learned over my years of public service to trust my instincts, and I told HQ that although the rovers were magnificent, the one thing that people will remember forever is the first heavier-than-air aircraft flying on Mars."

Culberson had the power of the purse. Whereas the White House appointed the leaders of NASA and set policy direction, Congress had to fund those endeavors. Culberson included budget line items for the helicopter even though NASA had not requested the money. And if they resisted? "As Chairman, it's possible to work a little magic," he explained. "I call it standing on their air hose, which helps them focus."

Knowing they had the backing of an influential congressman—I joined Culberson on several visits, including one with the Mars helicopter team in 2015, seeing his enthusiasm firsthand for the program—Aung and her team pressed ahead with the technical challenges.

The first hurdle to overcome was building a light enough vehicle that could fly. The rotors needed to be more than three feet (1 meter) long but stiff enough to rotate thousands of times per minute. The helicopter required a solar panel to collect energy and a stout set of batteries to store it. Then there were the cameras for imaging and navigation, a flight computer, and more.

"The biggest thing was mass. It was just such a big battle," Aung said.

Eventually, they settled on a top-line mass of 4 pounds (1.8 kg) and fought pitched battles over grams. A change in one area could have big implications downstream. For example, the energy budget called for using about half of the helicopter's power for flying and the other half to keep its batteries warm enough at night, when temperatures sometimes plummeted to -130° Fahrenheit (-90° C). As the team of about 20 people got into testing, however, they realized the thermal power needs were nearly twice what they had allocated. So they had to make difficult trades on the size of the solar array and batteries. But this, in turn, killed their mass margins. In the end, they fought for degrees. How warm, really, did Ingenuity's batteries need to be kept at night?

With van Zyl handling the programmatic concerns and keeping the bureaucracy of JPL at bay, Aung's team could focus on these technical problems. The set milestones, such as flight demonstrations, as markers of their progress.

"We were obsessed about meeting these milestones because we knew that for every one we didn't make, we could get cut off at that time," she said. "We were such a tight team and so focused on our goals. That's how we survived."

#BREAKING @NASA news!

By the summer of 2017, Thomas Zurbuchen knew a final decision had to be made soon. To assess the helicopter team's technical progress, he asked Bobby Braun, who by then had become dean of the University of Colorado Boulder College of Engineering and Applied Science, to review their work.

Originally skeptical of the idea, Braun came away impressed. He reported back to Zurbuchen that the concept had turned into a mature project. Aung's team passed the NASA review with flying colors.

Still, the science community and mission managers opposed it. Although Aung's team had satisfied NASA's concerns about the helicopter's risk to the Mars 2020 mission's overall success, there was a new worry. What if the helicopter got to the surface and then had a problem? How much of the rover's time would be consumed troubleshooting issues? How long would Perseverance be anchored to one spot? In a last-ditch effort to kill the helicopter, some scientists took their concerns public.

"This comes right out of science time," the project scientist for Mars 2020, Ken Farley, said in early May 2018. "I have personally been opposed to it because we are working very hard for efficiencies, and spending 30 days working on a technology demonstration does not further those goals directly from the science point of view."

But Zurbuchen's mind was made up. Ingenuity's team had met the two conditions he laid out a year earlier. Now, it was his turn to act. He realized the best way to win the space community's support would be to get top cover. He went to the relatively new NASA administrator, Jim Bridenstine, and told him the helicopter announcement would be better if it came from him. As a pilot, Bridenstine loved this kind of derring-do in an exploration mission. He was all in.

Accordingly, on May 11, 2018, Bridenstine announced the decision on Twitter. "#BREAKING @NASA news! Our next rover to Mars will carry the first helicopter ever to fly over the surface of another world," he wrote on the social network site. (After leaving as NASA administrator in early 2020, Bridenstine deleted his Twitter account). In an accompanying news release, Bridenstine was effusive. "The idea of a helicopter flying the skies of another planet is thrilling," he said. "The Mars Helicopter holds much promise for our future science, discovery, and exploration missions to Mars."

John Culberson was quoted right after Bridenstine.

Flying, finally

Braun moved to JPL in 2020 for a couple of years to run the Planetary Science and Mars programs. Even in the final months before launch, there were calls to pull Ingenuity off the rover because it was considered a distraction. Yet as he watched Aung and her team at work, Braun knew Zurbuchen had made the right decision.

"Any time you’re doing something new, and Ingenuity certainly qualifies, there’s always people lined up against it," Braun said. "It's no different from when we worked on Mars Pathfinder in the 1990s. All of the planetary science missions were getting to be big, and the establishment thought the idea of landing on Mars for something like $250 million in then-year dollars was a bit crazy. We were a bunch of kids who didn’t know better. It’s the kids who don’t know any better, and who are led by an experienced, diehard champion who believes—that’s how you make this stuff happen."

After a public contest, Ingenuity was named in April 2020 and launched three months later at the height of the pandemic. The Perseverance team had come together under Zurbuchen's dogged leadership to complete the rover and get it buttoned up for an on-time mission. It was a magical moment amid a summer of plague and racial strife.

The rover safely landed on Mars in February 2021, and in early April, Ingenuity successfully deployed onto the surface. On April 9, during the first key spin test, the software tripped up. After the team identified a fix, Ingenuity passed this 2,400 rpm test on April 16. Three days later, it flew for the first time. Aung and her team could finally take a deep breath and celebrate.

"For so long, I was living in this world where we must get at least one flight," she said. "We owed that to NASA. It felt amazing."

And then it kept flying. Again and again. This actually presented a problem. If Ingenuity was going to continue flying, it would require precious time from the rover to monitor its progress, plus relay communications between the helicopter and flight controllers back at JPL.

Zurbuchen said he gave Jennifer Harris Trosper, who was the Mars 2020 Project Manager at JPL, two options. He was not going to turn off the helicopter. Zurbuchen said the Mars 2020 team could work with the science community to find a way to continue supporting Ingenuity, or they could design a "hero" mission. This would be an arduous flight that would sacrifice the helicopter. Everyone would be a little sad, but it would free Perseverance to go on its merry way.

For Trosper and Ken Farley, it was an easy decision. They wanted Ingenuity to fly on as the machine had become a useful scouting tool.

Over the course of the next 33 months, Ingenuity survived long winter nights and dust storms, amazing us all by flying 72 missions. During its lifetime, Ingenuity spent a total of 2 hours and 9 minutes soaring through the thin Martian air.

Aung would have been happy with 40 seconds.

What it all means

I wrote a feature article in late January on Ingenuity's contributions to spaceflight. To summarize many words with a few: Ingenuity has forever changed how humans think about exploring other worlds by demonstrating flight in an extreme environment. Just as critically, it did so by using commercial, off-the-shelf parts (for mass reasons, primarily) that will be a boon in terms of cost and expediency for future missions. It's among the two or three most significant things NASA has done so far in the 21st century.

Based upon the policy struggle to fly Ingenuity, there are lessons to be drawn for NASA managers and policymakers.

"I think it is critical to do crazy and innovative things as part of most missions," Zurbuchen said. "It is also critical to do it the right way. You have to make sure a tech demo doesn’t blossom into a disaster and jeopardize the prime mission. But it’s really important that leadership support these kinds of things."

Braun agreed that NASA should continue to innovate and try new ideas. It is incumbent on the agency to find opportunities to reinvent the future.

"For NASA, there is a really important lesson," he said. "We need to try new things. We need to break out of the status quo ways of doing business because not only is it possible to succeed in different ways, but when we do, there are so many benefits."

One striking thing is that almost all of the key people who made this mission happen are gone from their roles. Zurbuchen retired from NASA at the end of 2022 after spending nearly seven years leading the science directorate. Aung left NASA in 2021 to take a project management role at Amazon for its Project Kuiper satellite constellation. Elachi retired in 2016. Culberson lost a reelection bid in 2020. Braun left JPL in 2022 to lead space exploration at the Johns Hopkins Applied Physics Laboratory. Balaram just retired from NASA. Tragically, van Zyl died of a heart attack in August 2020. He never got to see Ingenuity fly on Mars.

So there was just this ephemeral moment in time when the right people, with the right idea, came together to make something truly remarkable happen. And then they went their separate ways. We are incredibly fortunate it happened at all.

It's also notable how many people who made Ingenuity fly were not born in the United States. Zurbuchen spent the first three decades of his life in Switzerland before moving to the United States to take a job at the University of Michigan. Elachi was born in Lebanon and did not come to the United States until he sought a graduate degree from the California Institute of Technology. Aung was born in the United States to Burmese parents who were studying abroad at the University of Illinois Urbana-Champaign. However, she soon returned to Burma with them and only came to the United States 15 years later for college. Van Zyl was born in Namibia and Balaram in India.

They all found a home in the United States of America—and found the freedom to wander where their imaginations took them.

It turns out some of the informed speculation about the US military's latest X-37B spaceplane mission was pretty much spot-on.

When the semi-classified winged spacecraft launched on December 28, it flew into orbit on top of a SpaceX Falcon Heavy rocket, which is much larger than the Atlas V and Falcon 9 rockets used to launch the X-37B on its previous missions.

This immediately sparked speculation that the X-37B would reach higher altitudes than its past flights, which remained in low-Earth orbit at altitudes of a few hundred miles. A discovery from Tomi Simola, a satellite tracking hobbyist living near Helsinki, Finland, appears to confirm this suspicion.

On Friday, Simola reported on social media and on SeeSat-L, a long-running online forum of satellite tracking enthusiasts, that he detected an unidentified object using a sky-watching camera. The camera is designed to continuously observe a portion of the sky to detect moving objects in space. A special software program helps identify known and unknown objects.

"Exciting news!" Simola posted on social media. "Orbital Test Vehicle 7 (OTV-7), which was launched to classified orbit last December, was seen by my SatCam! Here are images from the last two nights!"

Mike McCants, one of the more experienced satellite observers and co-administrator of the SeeSat-L forum, agreed with Simola's conclusion that he found the X-37B spaceplane.

"Congrats to Tomi Simola for locating the secret X-37B spaceplane," posted Jonathan McDowell, an astrophysicist and widely respected expert in spaceflight activity.

Higher than ever

Amateur observations of the spaceplane indicate it is flying in a highly elliptical orbit ranging between 201 and 24,133 miles in altitude (323 and 38,838 kilometers). The orbit is inclined 59.1 degrees to the equator.

This is not far off the predictions from the hobbyist tracking community before the launch in December. At that time, enthusiasts used information about the Falcon Heavy's launch trajectory and drop zones for the rocket's core booster and upper stage to estimate the orbit it would reach with the X-37B spaceplane.

The Space Force has not released any information about the orbit of the X-37B. While it took hobbyists about six weeks to find the X-37B on this mission, it typically took less time for amateur trackers to locate it when it orbited at lower altitudes on its previous missions. Despite the secrecy, it's difficult to imagine the US military's adversaries in China and Russia didn't already know where the spaceplane was flying.

Military officials usually don't disclose details about the X-37B's missions while they are in space, providing updates only before each launch and then after each landing.

This is the seventh flight of an X-3B spaceplane since the first one launched in 2010. In a statement before the launch in December, the Space Force said this flight of the X-37B is focused on "a wide range of test and experimentation objectives." Flying in "new orbital regimes" is among the test objectives, military officials said.

The military has two Boeing-built X-37B spaceplanes, or Orbital Test Vehicles, in its inventory. They are reusable and designed to launch inside the payload fairing of a conventional rocket, spend multiple years in space with the use of solar power, and then return to Earth for a landing on a three-mile-long runway, either at Vandenberg Space Force Base in California or at NASA's Kennedy Space Center in Florida.

It resembles a miniature version of NASA's retired space shuttle orbiter, with wings, deployable landing gear, and black thermal protection tiles to shield its belly from the scorching heat of reentry. It measures 29 feet (about 9 meters) long, roughly a quarter of the length of NASA's space shuttle, and it doesn't carry astronauts.

The X-37B has a cargo bay inside the fuselage for payloads, with doors that open after launch and close before landing. There is also a service module mounted to the back end of the spaceplane to accommodate additional experiments, payloads, and small satellites that can deploy in orbit to perform their own missions.

All the Space Force has said about the payloads on the current X-37B flight is that its experiment package includes investigations into new "space domain awareness technologies." NASA is flying an experiment on the X-37B to measure how plant seeds respond to sustained exposure to space radiation. The spaceplane's orbit on this flight takes it through the Van Allen radiation belts.

The secrecy surrounding the X-37B has sparked much speculation about its purpose, some of which centers on ideas that the spaceplane is part of a classified weapons platform in orbit. More likely, analysts say, the X-37B is a testbed for new space technologies. The unusual elliptical orbit for this mission is similar to the orbit used for some of the Space Force's satellites designed to detect and warn of ballistic missile launches.

McDowell said this could mean the X-37B is testing out an infrared sensor for future early warning satellites, but then he cautioned this would be "just a wild speculation."

Speculation is about all we have to go on regarding the X-37B. But it seems we no longer need to speculate about where the X-37B is flying.