NASA will send a golf cart-sized robot to the moon in 2022 to search for deposits of water below the surface, an effort to evaluate the vital resource ahead of a planned human return to the moon in 2024 to possibly use it for astronauts to drink and to make rocket fuel, the U.S. space agency said on Friday. From a report: The VIPER robot will drive for miles (km) on the dusty lunar surface to get a closer look at what NASA administrator Jim Bridenstine has touted for months: underground pockets of "hundreds of millions of tons of water ice" that could help turn the moon into a jumping-off point to Mars. "VIPER is going to assess where the water ice is. We're going to be able to characterize the water ice, and ultimately drill," Bridenstine said on Friday at the International Astronautical Congress in Washington. "Why is this important? Because water ice represents something significant. Life support." VIPER stands for Volatiles Investigating Polar Exploration Rover.

Organic practices can reduce climate pollution produced directly from farming -- which would be fantastic if they didn't also require more land to produce the same amount of food. From a report: Clearing additional grasslands or forests to grow enough food to make up for that difference would release far more greenhouse gas than the practices initially reduce, a new study in Nature Communications finds. Other recent research has also concluded that organic farming produces more climate pollution than conventional practices when the additional land required is taken into account. In the new paper, researchers at the UK's Cranfield University took a broad look at the question by analyzing what would happen if all of England and Wales shifted entirely to these practices.

The good news is it would cut the direct greenhouse-gas emissions from livestock by 5% and from growing crops by 20% per unit of production. The bad news: it would slash yields by around 40%, forcing hungry Britons to import more food from overseas. If half the land used to meet that spike in demand was converted from grasslands, which store carbon in plant tissues, roots, and soil, it would boost overall greenhouse-gas emissions by 21%. Among other things, organic farming avoids the use of synthetic fertilizers, pesticides, and genetically modified organisms, all of which can boost the amount of crops produced per acre. Instead, organic farmers rely on things like animal manure and compost, and practices such as crop rotation, which involves growing different plants throughout the year to improve soil health. The study notes that these biological inputs produce fewer emissions than nitrogen-based synthetic fertilizers, notably including the highly potent greenhouse gas nitrous oxide. Separately, the use of manure and longer crop rotations can increase the amount of carbon stored in soil.

In a paper published on Arxiv, researchers from the Google Brain Team explain how they're training AI to recognize smells. Engadget reports: The researchers created a data set of nearly 5,000 molecules identified by perfumers, who labeled the molecules with descriptions ranging from "buttery" to "tropical" and "weedy." The team used about two-thirds of the data set to train its AI (a graph neural network or GNN) to associate molecules with the descriptors they often receive. The researchers then used the remaining scents to test the AI -- and it passed. The algorithms were able to predict molecules' smells based on their structures.

As Wired points out, there are a few caveats, and they are what make the science of smell so tricky. For starters, two people might describe the same scent differently, for instance "woody" or "earthy." Sometimes molecules have the same atoms and bonds, but they're arranged as mirror images and have completely different smells. Those are called chiral pairs; caraway and spearmint are just one example. Things get even more complicated when you start combining scents. Still, the Google researchers believe that training AI to associate specific molecules with their scents is an important first step. It could have an impact on chemistry, our understanding of human nutrition, sensory neuroscience and how we manufacture synthetic fragrance.

Scott K. Johnson from Ars Technica reports on how Flagstaff, Arizona, switched to energy-efficient LEDs without giving astronomers a headache from the harsh blue-rich light they produce. An anonymous reader shares several excerpts from the report: Flagstaff became the first city to earn a designation from the International Dark Sky Association in 2001. That came as a result of its long history of hosting astronomy research at local Lowell Observatory, as well as facilities operated by the U.S. Navy. The city has an official ordinance governing the use of outdoor lighting -- public and private. A few years ago, though, a problem arose. The type of dark-sky-friendly streetlight that the city had been using was going extinct, largely as a casualty of low demand. In fact, as of this summer, there are none left to buy. Meanwhile, the age of the LED streetlight has arrived with a catch: limited night-sky-friendly LED options. The problem with LEDs boils down to blue light. Older streetlights are high-pressure sodium bulbs, which produce a warm yellow glow around a color temperature of 2,000 K. The bulbs Flagstaff relied on for most of its streetlights were low-pressure sodium -- a variant that only emits light at a single wavelength (589 nanometers) near that yellow color, producing something resembling candlelight. Many of the LED streetlights on the market have much cooler color temperatures of 3,000 or even 4,000 K.

[...] Narrow-band amber (NBA) LEDs [...] actually use a type of LED that only emits warmer colors from the start. In this way, they actually compare pretty well to the low-pressure sodium streetlights that recently went extinct. The range of wavelengths emitted is a little broader, but the practical effect is about the same. Separately from all this wavelength wrangling, though, LEDs do have a strong natural advantage -- they're highly directional. That is, LED streetlights do a much better job of only lighting the street (rather than the adjacent homes). That means that fewer lumens coming out of the fixture can give the same result you had before. Flagstaff's plan is generally to swap in NBA LEDs for all the low-pressure sodium lights, and PCA LEDs [lights known as phosphor-converted amber (PCA) shift all the light out of the blue and into the yellow part of the spectrum at the cost of some efficiency] for the high-pressure sodium lights that are used along the busier streets (as they're a little brighter). The better directionality of LEDs -- combined with resident requests for slightly dimmer lighting on residential streets -- actually means that the total output of the city's streetlights is going to drop from about 29 million lumens to about 19 million lumens. That's not unusual. In closing, Johnson says Flagstaff's hope is to produce the first dark-sky ordinance updated to deal with LEDs that could give other cities an example to follow.

New submitter BytePusher shares a report from Phys.Org: U.S. scientists have reported successfully training a group of rodents to drive tiny cars in exchange for bits of Froot Loops cereal, and found that learning the task lowered their stress levels. Their study [published in the journal Behavioral Brain Research] not only demonstrates how sophisticated rat brains are, but could one day help in developing new non-pharmaceutical forms of treatment for mental illness, senior author Kelly Lambert of the University of Richmond told AFP on Wednesday. Lambert said she had long been interested in neuroplasticity -- how the brain changes in response to experience and challenges -- and particularly wanted to explore how well rats that were housed in more natural settings ("enriched environments") performed against those kept in labs.

She and colleagues modified a robot car kit by adding a clear plastic food container to form a driver compartment with an aluminum plate placed on the bottom. A copper wire was threaded horizontally across the cab to form three bars: left, center and right. When a rat placed itself on the aluminum floor and touched the wire, the circuit was complete and the car moved in the direction selected. Seventeen rats were trained over several months to drive around an arena 150 centimeters by 60 centimeters made of plexiglass. As she had suspected, Lambert found that the animals kept in stimuli-rich environments performed far better than their lab rat counterparts, but "it was actually quite shocking to me that they were so much better," she said. "This makes me curious what the implications are for humans, their work environments, job performance and social mobility," writes BytePusher.

Black patients were less likely than white patients to get extra medical help, despite being sicker, when an algorithm used by a large hospital chose who got the additional attention, according to a new study underscoring the risks as technology gains a foothold in medicine. The Wall Street Journal reports: Hospitals use the algorithm -- from Optum, UnitedHealth Group's health-services arm -- to find patients with diabetes, heart disease and other chronic ailments who could benefit from having health-care workers monitor their overall health, manage their prescriptions and juggle doctor visits, according to the study published Thursday in the journal Science. Yet the algorithm gave healthier white patients the same ranking as black patients who had one more chronic illness as well as poorer laboratory results and vital signs. The reason? The algorithm used cost to rank patients, and researchers found health-care spending for black patients was less than for white patients with similar medical conditions.

For the study, data-science researchers looked at the assessments made by one hospital's use of the algorithm. The study didn't name the hospital. The researchers focused on the algorithm's rankings of 6,079 patients who identified themselves as black in the hospital's records, and 43,539 who identified as white and didn't identify themselves as any other race or ethnicity. Then the researchers assessed the health needs of the same set of patients using their medical records, laboratory results and vital signs, and developed a different algorithm. Using that data, the researchers found that black patients were sicker than white patients who had a similar predicted cost. Among those rated the highest priority by the hospital's algorithm, black patients had 4.8 chronic diseases compared with 3.8 of the conditions among white patients. The researchers found the number of black patients eligible for fast-track enrollment in the program more than doubled by prioritizing patients based on their number of chronic conditions, rather than ranking them based on cost.

'Spacetime foam' might just be the wildest thing in the known universe, and we're just starting to understand it. From a report: A persistent cosmological puzzle has been troubling physicists since 1917: what is the universe made of? Complicating this already-mind-boggling question is the fact that our best theories conflict with our observations of the universe. Albert Einstein, according to scientific folklore, felt a unique responsibility for introducing this entire problem, reportedly referring to it as his "biggest blunder." Essentially, Einstein's novel theory of general relativity didn't hold up when used to describe the universe as a whole. General relativity described the "geometry" of spacetime as being a trampoline-like surface; planets are heavy bowling balls that distort the surface, creating curves. If a less heavy ball (like a marble) was placed near the bowling ball, it would roll along the surface just like the motion of planets in orbit. Thus, orbits are explained not by a gravitational "force" but by curvature in spacetime.

This proposal worked when considering small regions of spacetime. But when Einstein applied it to the entire universe, its predictions didn't fit. So, Einstein introduced the "cosmological constant," a fixed value that represents a kind of anti-gravity, anti-mass, and anti-energy, counteracting gravity's effects. But when scientists discovered that the universe was expanding rather than static, as Einstein had believed, the cosmological constant was set to zero and more or less ignored. After we learned that the universe's expansion is accelerating, however, scientists could no longer conveniently cancel out Einstein's anti-gravity suggestion. What was previously assumed to be empty space in the universe now had to be filled with huge amounts of mysterious anti-energy in order to explain observations of the universe's ever-quickening expansion. Even so, observations of the universe's expansion suggest that the energy is 60 to 120 orders of magnitude lower than what recent quantum field theory predicts.

What this means is that all of this extra energy is somehow missing when we look at the universe as a whole; either it's effectively hidden or very different in nature to the energy we do know about. Today, theoretical physicists are trying to reconcile these mysteries by examining the structure of so-called "spacetime" in the universe at the smallest possible scale, with surprising findings: spacetime might not be the trampoline-like plane scientists once envisioned -- it might be a foamy mess of bubbles all containing mini-universes living and dying inside our own.

Thousands of people have received brain scans, as well as cognitive and genetic tests, while participating in research studies. Though the data may be widely distributed among scientists, most participants assume their privacy is protected because researchers remove their names and other identifying information from their records. But could a curious family member identify one of them just from a brain scan? Could a company mining medical records to sell targeted ads do so, or someone who wants to embarrass a study participant?

The New York Times: The answer is yes, investigators at the Mayo Clinic reported on Wednesday. A magnetic resonance imaging scan includes the entire head, including the subject's face. And while the countenance is blurry, imaging technology has advanced to the point that the face can be reconstructed from the scan. Under some circumstances, that face can be matched to an individual with facial recognition software.

In a letter published in the New England Journal of Medicine, researchers at the Mayo Clinic showed that the required steps are not complex. But privacy experts questioned whether the process could be replicated on a much larger scale with today's technology. The subjects were 84 healthy participants in a long-term study of about 2,000 residents of Olmsted County, Minn. Participants get brain scans to look for signs of Alzheimer's disease, as well as cognitive, blood and genetic tests. Over the years, the study has accumulated over 6,000 M.R.I. scans.

sciencehabit shares a report from Science Magazine: Scientists have long suspected that neutron stars, the superdense remnants of burned out suns, are needed for this sort of rapid neutron capture. But until 2 years ago, they had never witnessed such an event. That's when the GW170817 merger happened. Taking place 140 million light-years away, astronomers first detected it from the gravitational waves generated by the stars crashing together. Computer modeling revealed that strontium in the expanding ball of gas would absorb light at wavelengths of 350 and 850 nanometers. When they looked again at the X-shooter spectra, they found dips in the spectra at those wavelengths. The end result: five Earth masses worth of strontium. The work confirms that at least some of the heavier elements are produced by merging neutron stars, and that neutrons stars really are made of neutrons. The findings have been published in the journal Nature.

An anonymous reader quotes a report from The Guardian: Soaring deforestation coupled with the destructive policies of Brazil's far-right president, Jair Bolsonaro, could push the Amazon rainforest dangerously to an irreversible "tipping point" within two years, a prominent economist has said. After this point the rainforest would stop producing enough rain to sustain itself and start slowly degrading into a drier savannah, releasing billions of tonnes of carbon into the atmosphere, which would exacerbate global heating and disrupt weather across South America.

The warning came in a policy brief published this week by Monica de Bolle, a senior fellow at the Peterson Institute for International Economics in Washington DC. The report sparked controversy among climate scientists. Some believe the tipping point is still 15 to 20 years away, while others say the warning accurately reflects the danger that Bolsonaro and global heating pose to the Amazon's survival. The policy brief noted that Brazil's space research institute, INPE, reported that deforestation in August was 222% higher than in August 2018. Maintaining the current rate of increase INPE reported between January and August this year would bring the Amazon "dangerously close to the estimated tipping point as soon as 2021 beyond which the rainforest can no longer generate enough rain to sustain itself", de Bolle wrote.

sciencehabit shares a report from Science Magazine: By harnessing the power of imagination, researchers have nearly doubled the speed at which completely paralyzed patients may be able to communicate with the outside world. In the new experiments, a volunteer paralyzed from the neck down instead imagined moving his arm to write each letter of the alphabet. That brain activity helped train a computer model known as a neural network to interpret the commands, tracing the intended trajectory of his imagined pen tip to create letters. Eventually, the computer could read out the volunteer's imagined sentences with roughly 95% accuracy at a speed of about 66 characters per minute -- twice the previous record.

Blink-182 singer Tom DeLonge's UFO research organization has signed an agreement with the U.S. Army in which it will help the military study and develop advanced materials for the purposes of develpoing "active camouflage, beamed energy propulsion, and quantum communication" for use on military vehicles. Motherboard reports: On October 17th, To the Stars joined forces with the Army's Combat Capabilities Development Command, a research and development body. While To the Stars has made recent headlines with its UFO themed content, such as its acquisition of "exotic" materials which it claims are not from Earth, and videos acquired from the Navy purporting to show unidentified anomalous phenomena, this recent deal with the military portrays a different side of To the Stars: as a potential technology company.

In recent months, DeLonge's organization has made a big deal out of obtaining those "exotic" metals that it believes may come from UFOs. Though the contract doesn't specifically mention the origin of any of those metals, it does say that To the Stars and the U.S. Army will use government labs to study "meta materials," which could refer to these alloys. "Government shall: Perform assessments, testing, and characterization of Collaborator-provided technologies. The Government is interested in a variety of the Collaborator's technologies, such as, but not limited to inertial mass reduction, mechanical/structural meta materials, electromagnetic meta material wave guides, quantum physics, quantum communications, and beamed energy propulsion," the contract states. The contract lasts for five years. The government isn't paying TTSA anything, rather, it is agreeing to collaborate with TTSA on researching new technologies and has committed to spend at least $750,000 on the research.

An anonymous reader quotes a report from the BBC: Higher air pollution in the UK trigger hundreds more heart attacks, strokes and acute asthma attacks each year, research suggests. A team at King's College London looked at data from London, Birmingham, Bristol, Derby, Liverpool, Manchester, Nottingham, Oxford and Southampton. They calculated days with above average pollution levels would see an extra 124 cardiac arrests over the year. On days with high pollution levels, across the nine cities in total, they calculated that there would be a total of 231 additional hospital admissions for stroke, with an extra 193 children and adults taken to hospital for asthma treatment. Dr Heather Walton, of King's College London's Environmental Research Group, said air pollution reduction policies concentrated in the main on effects connected to life expectancy.

In London, high-pollution days would see an extra 87 cardiac arrests per year, an extra 144 strokes, and 74 children and 33 adults ending up in hospital with asthma-related issues. In Birmingham the figure would be 12 more out-of-hospital cardiac arrests, 27 additional admissions for stroke and 26 more for asthma. Bristol, Liverpool, Manchester, Nottingham, Oxford and Southampton would see between two and six more out-of-hospital heart attacks and up to 14 extra hospital admissions for both stroke and asthma. Only in Derby would there be no apparent increase. The research suggests cutting air pollution by a fifth would decrease incidents of lung cancer by between 5% and 7% across the nine cities surveyed.

After analyzing fossil records from 66 million years ago, researchers determined that ocean acidification can cause the mass extinction of marine life. The Guardian reports: The researchers analysed small seashells in sediment laid down shortly after a giant meteorite hit the Earth, wiping out the dinosaurs and three-quarters of marine species. Chemical analysis of the shells showed a sharp drop in the pH of the ocean in the century to the millennium after the strike. This spike demonstrated it was the meteorite impact that made the ocean more acidic, effectively dissolving the chalky shells of many species. Large-scale volcanic activity was also considered a possible culprit, but this occurred over a much longer period.

The oceans acidified because the meteorite impact vaporized rocks containing sulphates and carbonates, causing sulphuric acid and carbonic acid to rain down. The mass die-off of plants on land after the strike also increased CO2 in the atmosphere. The researchers found that the pH dropped by 0.25 pH units in the 100-1,000 years after the strike. It is possible that there was an even bigger drop in pH in the decade or two after the strike and the scientists are examining other sediments in even finer detail. [Michael Henehan at the GFZ German research center for geosciences in Potsdam said]: âoeIf 0.25 was enough to precipitate a mass extinction, we should be worried.â Researchers estimate that the pH of the ocean will drop by 0.4 pH units by the end of this century if carbon emissions are not stopped, or by 0.15 units if global temperature rise is limited to 2C. Henehan said: âoeWe may think of [acidification] as something to worry about for our grandchildren. But if it truly does get to the same acidification as at the [meteorite strike] boundary, then you are talking about effects that will last for the lifetime of our species. It was hundreds of thousands of years before carbon cycling returned to normal.â The research has been published in the journal Proceedings of the National Academy of Sciences.

Scientists have raised fresh hopes for treating people with genetic disorders by inventing a powerful new molecular tool that, in principle, can correct the vast majority of mutations that cause human genetic diseases. From a report: The procedure, named "prime editing," can mend about 89% of the 75,000 or so harmful mutations known to mangle the human genome and lead to conditions such as cystic fibrosis, sickle cell anaemia, and a nerve-destroying illness called Tay-Sachs disease. The landmark work opens the door to a new era of genome editing, but scientists caution that more research is needed before it can be safely used in humans. Beyond proving its safety, another major hurdle is how to deliver the molecular machinery to cells that need it in sufficient amounts to treat a disorder.

"This first report of prime editing is the beginning rather than the end of a longstanding aspiration in the life sciences to be able to make any DNA change in any position of a living cell or organism, including potentially human patients with genetic diseases," said David Liu at the Broad Institute of MIT and Harvard in Cambridge, Massachusetts. The ability to rewrite the genetic code is one of the most striking scientific advances of recent years. The most common approach, known as Crispr-Cas9, has been likened to "molecular scissors" which home in on a particular DNA sequence and then cut it in two. The procedure allows scientists to disable specific genes and even correct harmful mutations by providing cells with fresh strands of DNA with which to repair the cut.

A Swedish engineer's umbrage at a traffic ticket has led to a six-year legal fight and now a global change in the speed with which traffic light signals are timed. From a report: After Mats Jarlstrom lost an initial legal challenge in 2014, a federal judge in January this year ruled Oregon's rules prohibiting people from representing themselves as engineers without a professional license from the state are unconstitutional. And now Jarlstrom's calculations and advocacy have led the Institute of Transportation Engineers (ITE) to revisit its guidelines for the timing of traffic signals. As a result, yellow lights around the globe could burn for longer -- ITE is an international advisory group with members in 90 countries. Jarlstrom discovered a problem with the timing of traffic lights in Beaverton, Oregon, after his wife Laurie received a $260 ticket for a red light violation from an automated traffic light camera in 2013. Jarlstrom, who studied electrical engineering in Sweden, challenged the ticket, arguing the timing interval for yellow lights fails to account for scenarios like a driver entering an intersection and slowing to make a turn. A slightly longer interval, he argued, would allow drivers making turns on a yellow light to exit intersections before the light turned red. Even a small timing increase would help -- the automatically generated ticket in this case was issued 0.12 seconds after the light turned red.

In Venezuela, a crumbling economy and the collapse of even basic state infrastructure means water comes irregularly -- and drinking it is an increasingly risky gamble. Venezuela's current rate of infant mortality from diarrhea, which is closely related to water quality, is six times higher than 15 years ago, according to the World Health Organization. From a report: But the government stopped releasing official public health data years ago. So The New York Times commissioned researchers from the Universidad Central de Venezuela to recreate the water quality study they had conducted regularly for the water utility in Caracas from 1992 until 1999. The scientists found that about a million residents were exposed to contaminated supplies. This puts them at risk of contracting waterborne viruses that could sicken them and threatens the lives of children and the most vulnerable. "This is a potential epidemic," said Jose MarÃa De Viana, who headed Caracas's water utility, Hidrocapital, until 1999. "It's very serious. It's unacceptable."

In the latest study, 40 samples were taken from the capital's main water systems and tested for bacteria and for chlorine, which keeps water safe. The study also tested alternative water sources used by city residents during supply outages. One third of the samples did not meet national norms. This should have required Hidrocapital to issue a sanitation alert, according to the utility's own internal regulations. But Venezuela's government has not issued any alerts at least since President Nicolas Maduro's Socialist Party took power 20 years ago. "The biggest health risk that we see there right now is water -- water and sanitation," the head of the International Federation of the Red Cross, Francesco Rocca, told foreign reporters this week, referring to Venezuela.

An anonymous reader quotes Popular Mechanics: An assistant professor from the University of New South Wales Sydney in Australia has developed a new method for multiplying giant numbers together that's more efficient than the "long multiplication" so many are taught at an early age. "More technically, we have proved a 1971 conjecture of Schönhage and Strassen about the complexity of integer multiplication," associate professor David Harvey says in this video...

Schönhage and Strassen predicted that an algorithm multiplying n-digit numbers using n * log(n) basic operations should exist, Harvey says. His paper is the first known proof that it does...

The [original 1971] Schönhage-Strassen method is very fast, Harvey says. If a computer were to use the squared method taught in school on a problem where two numbers had a billion digits each, it would take months. A computer using the Schönhage-Strassen method could do so in 30 seconds. But if the numbers keep rising into the trillions and beyond, the algorithm developed by Harvey and collaborator Joris van der Hoeven at École Polytechnique in France could find solutions faster than the 1971 Schönhage-Strassen algorithm.

"It means you can do all sorts of arithmetic more efficiently, for example division and square roots," he says. "You could also calculate digits of pi more efficiently than before. It even has applications to problems involving huge prime numbers.
"The question is, how deep does n have to be for this algorithm to actually be faster than the previous algorithms?" the assistant professor says in the video. "The answer is we don't know.

"It could be billions of digits. It could be trillions. It could be much bigger than that. We really have no idea at this point."

Dream McClinton from The Guardian writes about a new Netflix docuseries, called Unnatural Selection, that "explores the various forms of genetic engineering, as well as the societal and environmental implications of its research and use." An anonymous reader shares an excerpt from the report: Today, we are learning the language in which God created life," said then-president Bill Clinton, alongside the British prime minister, Tony Blair, in 2000. In the grainy archival clip, scientists and dignitaries had just mapped out the human genome, dissecting the complex science of biological being to code sequences of A, C, G and T in a style similar to binary computer code. But almost 20 years later, science has surpassed this once-unimaginable feat with the discovery of technology which can alter that genetic code. This zeitgeist-y innovation is the subject of a new Netflix series, Unnatural Selection, from film-makers Joe Egender and Leeor Kaufman, and explores the various forms of genetic engineering, as well as the societal and environmental implications of its research and use.

The four-part docuseries delves into the burgeoning field of gene technology, made possible by the aforementioned human genome project and the discovery of the Clustered Regularly Interspaced Short Palindromic Repeats or Crispr. Co-discovered by Dr Jennifer Doudna, the gene serves a bit like "a molecular scalpel", she says, essentially removing and replacing gene material in a DNA strand. The technology makes it possible to modify genetics, giving it near unlimited biological potential, or as Salk Institute developmental biologist Professor Juan Izpuisua Belmonte puts it, "... rewriting the book of life." For Egender and Kaufman, the series had to tell the broader, more intricate story of genetic engineering, a story filled with great risk, benefits, consequences, emotions, sentiments and future, to better illuminate the field and further the discussion on the technology. "[M]any are depending on gene therapy treatment to change and possibly save lives," writes McClinton. "But, the series shows, the treatments are expensive, with some emerging drugs costing over $500,000, and patients are often at the mercy of startup genetic therapy companies who choose to weigh the 'meaning' of the treatment versus the cost for the patient, leaving many to fight their insurance companies for the cost of treatment."

U.S. astronauts Christina Koch and Jessica Meir made history on Friday when they stepped outside the International Space Station (ISS) on the first all-female spacewalk. From a report: The much-anticipated milestone for NASA was achieved during a relatively routine mission to swap faulty batteries on the station's exterior. Koch and Meir, clad in white spacesuits and tethered by cords to the station some 254 miles (408 km) above Earth, stepped into outer space at 7:38 a.m. Eastern time (1138 GMT) to replace a faulty power unit designed to help condition energy stored from the station's solar panels, NASA announced online as it showed live video of the action. Today, President Trump took a few moments out of his day to speak with Koch and Meir. From a report: While speaking with the pair, Trump mistakenly suggested this was the first female spacewalk ever -- a point that the astronauts corrected him on. "This is the first time for a woman outside of the space station," Trump said. He later added: "You are amazing people; they're conducting the first ever female spacewalk to replace an exterior part of the space station. They're doing some work, and they're doing it in a very high altitude -- an altitude that very few people will ever see." In her response, Meir made it clear that they were building on the work of many previous women who had spacewalked before them. "We don't want to take too much credit because there have been many other female spacewalkers before," Meir said. "This is the first time that there's been two women outside at the same time." In the history of spaceflight, only 15 women have ever spacewalked, including Meir and Koch.