A quick nap in the middle of the day might do more than fight off drowsiness. A study recently published in the journal NeuroImage reports that a brief afternoon sleep can shift how brain cells connect with one another, making it easier to take in and store new information. The research team, based at the Medical Center – University of Freiburg and the University of Geneva, found that this kind of reset does not necessarily require a full night’s sleep.

The idea is simple: as you move through the day, the brain keeps strengthening communication pathways as it processes sights, ideas, and experiences. That strengthening supports learning, but it can also crowd the system, leaving the brain less flexible for what comes next. In the new work, a short sleep period appeared to dial back that built-up activity and restore the brain’s readiness to learn, which could be especially useful during periods of high workload.

“Our results suggest that even short periods of sleep enhance the brain’s capacity to encode new information,” says study leader Prof. Dr. Christoph Nissen, who performed the study during his time as medical director of the sleep center at the Department of Psychiatry and Psychotherapy at the Medical Center – University of Freiburg, Germany

Certain cancers are extremely difficult to treat, and carcinomas are among the most stubborn. Unlike many other malignancies, these tumors can behave in unusual ways. Some have the ability to shift their identity, taking on characteristics of cells from entirely different organs, including skin. This shape-changing behavior makes them especially hard to target with current therapies. “The tumors are notoriously plastic in their cellular identity,” says Cold Spring Harbor Laboratory (CSHL) Professor Christopher Vakoc. In some cases, this flexibility allows tumors to adapt and survive treatment.

New Studies Reveal Vulnerabilities in Pancreatic and Lung Cancer
Recent research from the Vakoc lab has uncovered important weaknesses in two particularly challenging carcinomas. According to Vakoc, these discoveries may “tee up targets for therapy.”

In a study published in Nature Communications, CSHL scientists identified a protein that controls whether pancreatic cancer cells keep their traditional identity or begin to resemble and behave like skin cells. In separate work reported in Cell Reports, the team determined the crystal structure of another group of proteins that is central to tuft cell lung cancer.

Continuous sleep is a modern habit, not an evolutionary constant, which helps explain why many of us still wake at 3 am and wonder if something's wrong. It might help to know that this is a deeply human experience.

For most of human history, a continuous eight-hour snooze was not the norm. Instead, people commonly slept in two shifts each night, often called a "first sleep" and "second sleep."

Each of these sleeps lasted several hours, separated by a gap of wakefulness for an hour or more in the middle of the night. Historical records from Europe, Africa, Asia, and beyond describe how, after nightfall, families would go to bed early, then wake around midnight for a while before returning to sleep until dawn.

Breaking the night into two parts probably changed how time felt. The quiet interval gave nights a clear middle, which can make long winter evenings feel less continuous and easier to manage.

The midnight interval was not dead time; it was noticed time, which shapes how long nights are experienced.

Some people would get up to tend to chores like stirring the fire or checking on animals. Others stayed in bed to pray or contemplate dreams they'd just had. Letters and diaries from pre-industrial times mention people using the quiet hours to read, write, or even socialise quietly with family or neighbours. Many couples took advantage of this midnight wakefulness for intimacy.

Literature from as far back as ancient Greek poet Homer and Roman poet Virgil contains references to an "hour which terminates the first sleep," indicating how commonplace the two-shift night was.

How we lost the 'second sleep'
The disappearance of the second sleep happened over the past two centuries due to profound societal changes.

Artificial lighting is one of them. In the 1700s and 1800s, first oil lamps, then gas lighting, and eventually electric light, began turning night into more usable waking time. Instead of going to bed shortly after sunset, people started staying up later into the evening under lamplight.

Bacteria have evolved to adapt to all of Earth's most extreme conditions, from scorching heat to temperatures well below zero. Ice caves are just one of the environments hosting a variety of microorganisms that represent a source of genetic diversity that has not yet been studied extensively. Now, researchers in Romania tested antibiotic resistance profiles of a bacterial strain that until recently was hidden in a 5,000-year-old layer of ice of an underground ice cave—and found it could be an opportunity for developing new strategies to prevent the rise of antibiotic resistance and study how resistance naturally evolves and spreads. They reported their discovery in Frontiers in Microbiology.

"The Psychrobacter SC65A.3 bacterial strain isolated from Scarisoara Ice Cave, despite its ancient origin, shows resistance to multiple modern antibiotics and carries over 100 resistance-related genes," said author Dr. Cristina Purcarea, a senior scientist at the Institute of Biology Bucharest of the Romanian Academy. "But it can also inhibit the growth of several major antibiotic-resistant 'superbugs' and showed important enzymatic activities with important biotechnological potential."

Ancient resistance to modern medication
Psychrobacter SC65A.3 is a strain of the genus Psychrobacter, which are bacteria adapted to cold environments. Some species can cause infections in humans or animals. Psychrobacter bacteria have biotechnological potential, but the antibiotic resistance profiles of these bacteria are largely unknown.

"Studying microbes such as Psychrobacter SC65A.3 retrieved from millennia-old cave ice deposits reveals how antibiotic resistance evolved naturally in the environment, long before modern antibiotics were ever used," said Purcarea.

Formed over millions of years, the layered sandstone cliffs of Utah's Zion National Park reveal the climates, conditions, and transformations that shaped the landscape.

Scientists at the University of Oxford have created an advanced technique that allows them to clearly see a crucial but previously hard-to-detect part of lithium-ion battery electrodes. The findings, published today (February 17) in Nature Communications, could improve how battery electrodes are manufactured and lead to faster charging and longer-lasting Li-ion batteries.

The research centers on polymer binders used in the negative electrodes of lithium-ion batteries (anodes). Although these binders account for less than 5% of the electrode’s weight, they play an essential role in keeping the electrode intact. They influence mechanical strength, electrical and ionic conductivity, and overall battery lifespan. Because binders lack distinctive visual features and are present in such small amounts, scientists have struggled to track where they are located inside the electrode. That limitation has made it difficult to fine-tune battery performance, since binder placement directly affects conductivity, structural stability, and durability over time.

Patent Pending Staining Technique Makes Binders Visible
To solve this long-standing challenge, the team developed a patent-pending staining method that attaches traceable silver and bromine markers to widely used cellulose- and latex-based binders in both graphite- and silicon-based anodes. Once tagged, the binders can be detected because they emit characteristic X-rays (measured with energy-dispersive X-ray spectroscopy) or reflect high-energy electrons from the surface (measured with energy-selective backscattered electron imaging). Under an electron microscope, these signals reveal detailed information about where elements are distributed and what the surface structure looks like.

In 2025, planetary scientists reported the detection of long-chain alkanes at concentrations of roughly 30 to 50 parts per billion in the ancient Cumberland mudstone in Gale crater, Mars.

They proposed that the alkanes were derived from thermal decarboxylation of fatty acids during analysis by Curiosity’s Sample Analysis at Mars (SAM) instrument.

In a new study, Dr. Alexander Pavlov from NASA’s Goddard Space Flight Center and his colleagues argue that the measured values are merely a lower limit, because most of the original organic material was likely destroyed by radiation over tens of millions of years.

The Cumberland mudstone may originally have contained between 120 and 7,700 parts per million of long-chain alkanes or their fatty-acid precursors before it was exposed at the surface.

“To reach this conclusion, we combined lab radiation experiments, mathematical modeling, and Curiosity data to ‘rewind the clock’ about 80 million years — the length of time the rock would have been exposed on the Martian surface,” the researchers said.

“This allowed us to estimate how much organic material would have been present before being destroyed by long-term exposure to cosmic radiation: far more than typical non-biological processes could produce.”

The scientists also assessed whether known non-biological processes could explain the unusually high inferred abundance of long-chain alkanes.

According to the study, delivery by meteorites and interplanetary dust particles is insufficient by many orders of magnitude, given the estimated sedimentation rates and the inability of dust particles to penetrate lithified rock.

Atmospheric production of organic haze is also unlikely, because early Mars probably lacked the methane-rich conditions required to generate substantial haze deposition.

The authors also examined hydrothermal processes that can produce hydrocarbons under certain conditions.

While lab experiments show that long-chain organic molecules can form hydrothermally, the mineralogy of the Cumberland mudstone indicates it did not experience the high temperatures associated with such reactions.

The findings suggest a more speculative possibility: that some or all of the original organic material could have been produced by a hypothetical ancient Martian biosphere.

“We agree with Carl Sagan’s claim that extraordinary claims require extraordinary evidence and understand that any purported detection of life on Mars will necessarily be met with intense scrutiny,” the researchers said.

“In addition, in practice with established norms in the field of astrobiology, we note that the certainty of a life detection beyond Earth will require multiple lines of evidence.”

Older adults who are exposed to higher levels of air pollution appear more likely to develop Alzheimer’s disease, according to new research led by Yanling Deng of Emory University.

Alzheimer’s disease is the leading cause of dementia, affecting an estimated 57 million people worldwide. Air pollution has already been identified as a risk factor not only for Alzheimer’s, but also for several chronic conditions, including hypertension, stroke, and depression. These same health problems are also associated with dementia. Until now, however, scientists were unsure whether polluted air increases dementia risk by first contributing to these chronic illnesses, or whether those illnesses simply make the brain more vulnerable to pollution’s effects.

Massive Medicare Study Examines 27.8 Million Older Adults
To investigate, researchers analyzed data from more than 27.8 million U.S. Medicare beneficiaries age 65 and older between 2000 and 2018. They compared long term exposure to air pollution with new diagnoses of Alzheimer’s disease, while also examining whether conditions such as stroke, hypertension, and depression influenced the relationship.

The results showed a clear pattern. Higher exposure to air pollution was linked to a greater risk of developing Alzheimer’s disease. The association was somewhat stronger among individuals who had previously experienced a stroke. In contrast, hypertension and depression did not appear to significantly intensify the pollution-related risk.

Scientists at Mayo Clinic have uncovered a molecular “switch” inside lung cells that determines whether those cells focus on healing damaged tissue or defending against infection. The discovery offers new insight that could shape future regenerative treatments for chronic lung diseases.

“We were surprised to find that these specialized cells cannot do both jobs at once,” says Douglas Brownfield, Ph.D., senior author of the study published in Nature Communications. “Some commit to rebuilding, while others focus on defense. That division of labor is essential. And by uncovering the switch that controls it, we can start thinking about how to restore balance when it breaks down in disease.”

The Dual Role of Alveolar Type 2 (AT2) Cells
The research centers on alveolar type 2 (AT2) cells, which play a critical role in lung health. These cells help maintain the air sacs by producing proteins that keep them open during breathing. At the same time, they serve as reserve stem cells capable of replacing alveolar type 1 (AT1) cells, the thin cells that form the surface where oxygen passes into the bloodstream.

For years, researchers have observed that AT2 cells often fail to regenerate effectively in conditions such as pulmonary fibrosis, chronic obstructive pulmonary disease (COPD), and severe viral infections including COVID-19. However, the biological reason these cells lose their regenerative ability had not been fully understood.

In early February 2026, the Sun unleashed a torrent of back-to-back solar flares. One specific active region on the Sun was responsible for over 50 of them!

Here’s a close up from NASA’s Solar Dynamics Observatory. 🤩

Out of the way please!

Did you know baby elephants are covered in fine hair that fades as they grow. Those tiny hairs help them stay cool!

📸 Nishant Singh

The second wet dress rehearsal for the Artemis II mission continues as teams power up the rocket’s core stage — which contains propellant tanks — and charge the Orion spacecraft’s flight batteries.

Tomorrow, teams will practice fueling the rocket. go.nasa.gov/4qIwL40

A new technology developed at NASA’s Jet Propulsion Laboratory in Southern California enables Perseverance to figure out its whereabouts without calling humans for help. Dubbed Mars Global Localization, the technology features an algorithm that rapidly compares panoramic images from the rover’s navigation cameras with onboard orbital terrain maps. Running on a powerful processor that Perseverance originally used to communicate with the Ingenuity Mars Helicopter, the algorithm takes about two minutes to pinpoint the rover’s location within some 10 inches (25 centimeters). Mars Global Localization was first used successfully in regular mission operations on Feb. 2, then again Feb. 16.

“This is kind of like giving the rover GPS. Now it can determine its own location on Mars,” said JPL’s Vandi Verma, chief engineer of robotics operations for the mission. “It means the rover will be able to drive for much longer distances autonomously, so we’ll explore more of the planet and get more science. And it could be used by almost any other rover traveling fast and far.”

The upgrade is especially valuable given how well Perseverance’s auto-navigation self-driving system has been working. Enabling the rover to re-plan its path around obstacles en route to a preestablished destination, AutoNav has proved so capable that the distance Perseverance can drive without instructions from Earth is largely limited by the rover’s uncertainty about its whereabouts. Now that it can stop and determine its exact location, Perseverance can be commanded to drive to potentially unlimited distances without calling home.

Implementation of Mars Global Localization comes on the heels of another innovation from the Perseverance team: the first use of generative artificial intelligence to help plan a drive route by selecting waypoints for the rover, which are normally chosen by human rover operators. Both technologies enable Perseverance to travel farther and faster while minimizing team workload.

Beyond visual odometry
Unlike on Earth, there is no network of GPS satellites in deep space to locate spacecraft on planetary surfaces. So missions — whether robotic or crewed — must come up with other ways to determine their location.

As with NASA’s previous Mars rovers, Perseverance tracks its position using what’s called visual odometry, analyzing geologic features in camera images taken every few feet while accounting for wheel slippage. But as tiny errors in the process add up over the course of each drive, the rover becomes increasingly unsure about its exact location. On long drives, the rover’s sense of its position can be off by more than 100 feet (up to 35 meters). Believing it may be too close to hazardous terrain, Perseverance may prematurely end its drive and wait for instructions from Earth.

“Humans have to tell it, ‘You’re not lost, you’re safe. Keep going,’” Verma said. “We knew if we addressed this problem, the rover could travel much farther every day.” After each drive comes to a halt, the rover sends a 360-degree panorama to Earth, where mapping experts match the imagery with shots from NASA’s Mars Reconnaissance Orbiter (MRO). The team then sends the rover its location and instructions for its next drive. That process can take a day or more, but with Mars Global Localization, the rover is able to compare the images itself, determine its location, and roll ahead on its preplanned route.

How Ingenuity helped
Key to Mars Global Localization is the rover’s Helicopter Base Station (HBS), which Perseverance used to communicate with the now-retired Ingenuity Mars Helicopter. Equipped with a commercial processor that powered many consumer smartphones in the mid-2010s, the HBS runs more than 100 times faster than the rover’s two main computers, which, built to survive the radiation-heavy Martian environment, are based on hardware introduced in 1997...

Scientists have created a three-dimensional "heart-on-a-chip" (HOC) that could provide a breakthrough in the fight against the world's leading cause of death, cardiovascular disease.

One major challenge is that we cannot easily test how a human heart will react to a drug or disease without putting someone at risk. This engineered heart tissue beats on its own, it mobilizes calcium to initiate muscular activity, and it responds predictably to common drugs.

It's the first to incorporate a dual-sensing platform that provides real-time tracking of activity throughout the heart tissue down to the cellular level.

In a recent paper, scientists from multiple Canadian institutions describe how they achieved this "significant advance in cardiac tissue engineering and pharmacological testing."

The key advance here is the integration of sensors that can detect both macro-scale and micro-scale cardiac activity. Both current HOC platforms and the research team's previous iteration, described in a 2024 paper, lack high-resolution cellular-level sensing.

For years, scientists have agreed on a broad explanation for how complex life first appeared on Earth, yet one critical question remained unanswered. Plants, animals, and fungi, collectively known as eukaryotes, are thought to have emerged when two very different microbes joined forces. One depended on oxygen to survive, while the other was believed to live only in oxygen-free environments. What puzzled researchers was how these two organisms could have encountered each other in the first place.

A new study from The University of Texas at Austin, published today (February 18) in the journal Nature, offers a compelling answer. Researchers focused on a group of microbes called Asgard archaea, widely considered close relatives of the ancestors of complex life. Although most known Asgard archaea inhabit deep-sea, oxygen-free settings, the team discovered that some members of this group can tolerate or even use oxygen. This finding strengthens the theory that complex life evolved in oxygen-rich conditions.

“Most Asgards alive today have been found in environments without oxygen,” explained Brett Baker an associate professor of marine science and integrative biology at UT. “But it turns out that the ones most closely related to eukaryotes live in places with oxygen, such as shallow coastal sediments and floating in the water column, and they have a lot of metabolic pathways that use oxygen. That suggests that our eukaryotic ancestor likely had these processes, too.”

The gut microbiome, also called the gut flora, is essential to human health. This vast and constantly changing community of microorganisms depends on a web of chemical exchanges. Microbes communicate not only with one another but also with the human body that hosts them. To function properly, gut bacteria must detect nutrients and signaling molecules in their surroundings. However, scientists still do not fully understand the wide range of chemical signals that bacterial receptors are able to recognize.

A key question remains: which of these signals are most important for beneficial gut bacteria?

Moving Beyond Pathogens in Bacterial Research
Most research on bacterial sensing has focused on model organisms, particularly disease-causing microbes. Far less attention has been given to commensals, the non-pathogenic and often beneficial bacteria that naturally live in humans. This has left an important gap in understanding what kinds of chemical signals these helpful microbes actually detect in the gut.

An international team led by Victor Sourjik sought to answer that question. The researchers, from the Max Planck Institute for Terrestrial Microbiology, the University of Ohio, and Philipps-University Marburg, investigated Clostridia. These motile bacteria are abundant in the intestinal flora and play a major role in maintaining gut health.

Gut Bacteria Recognize a Wide Range of Nutrients
The team found that receptors from bacteria in the human gut microbiome respond to a surprisingly broad range of metabolic compounds. These include breakdown products of carbohydrates, fats, proteins, DNA, and amines. Through systematic screening, the scientists observed that different types of bacterial sensors show clear preferences for specific classes of chemicals.

This indicates that gut bacteria are selectively tuned to certain metabolic signals rather than reacting randomly to everything in their environment.

In the BioAsteroid project, University of Edinburgh’s Professor Charles Cockell and his colleagues used the bacterial species Sphingomonas desiccabilis and the fungus species Penicillium simplicissimum to see which elements could potentially be extracted from L-chondrite asteroidal material.

But understanding how the microbes interact with rocks in microgravity was equally important.

“This is probably the first experiment of its kind on the International Space Station on meteorite,” said Dr. Rosa Santomartino, a researcher at Cornell University and the University of Edinburgh.

“We wanted to keep the approach tailored in a way, but also general to increase its impact.”

“These are two completely different species, and they will extract different things.”

“So, we wanted to understand how and what, but keep the results relevant for a broader perspective, because not much is known about the mechanisms that influence microbial behavior in space.”

People cannot survive without lungs. Yet one of Ankit Bharat’s patients did so for two full days.

In a study published in the Cell Press journal Med, surgeons detailed how they extracted a patient’s severely infected lungs and relied on a custom-built “artificial lungs” setup to sustain him until donor organs became available. The team describes the strategy as a potential bridge to transplantation for patients who would otherwise die waiting.

“He was critically ill. His heart stopped as soon as he arrived. We had to perform CPR,” recalls Bharat, the lead author and a thoracic surgeon at Northwestern University. “When the infection is so severe that the lungs are melting, they’re irrecoverably damaged. That’s when patients die.”

Joshi is the author of a new report, released Monday with support from several environmental organizations, that attempts to quantify some of the most high-profile claims made about how AI will save the planet. The report looks at more than claims made by tech companies, energy associations, and others about how "AI will serve as a net climate benefit.” Joshi’s analysis finds that just a quarter of those claims were backed up by academic research, while more than a third did not publicly cite any evidence at all.

“People make assertions about the kind of societal impacts of AI and the effects on the energy system—those assertions often lack rigor,” says Jon Koomey, an energy and technology researcher who was not involved in Joshi’s report. “It's important not to take self-interested claims at face value. Some of those claims may be true, but you have to be very careful. I think there's a lot of people who make these statements without much support.”

Another important topic the report explores is what kind of AI, exactly, tech companies are talking about when they talk about AI saving the planet. Many types of AI are less energy-intensive than the generative, consumer-focused models that have dominated headlines in recent years, which require massive amounts of compute—and power—to train and operate. Machine learning has been a staple of many scientific disciplines for decades. But it’s large-scale generative AI—especially tools like ChatGPT, Claude, and Google Gemini—that are the public focus of much of tech companies’ infrastructure buildout. Joshi’s analysis found that nearly all of the claims he examined conflated more traditional, less energy-intensive forms of AI with the consumer-focused generative AI that is driving much of the buildout of data centers.

Preliminary analysis suggests CDG-2 has the luminosity of roughly 6 million sun-like stars, with the globular clusters accounting for 16% of its visible content. Remarkably, 99% of its mass, which includes both visible matter and dark matter, appears to be dark matter. Much of its normal matter to enable star formation—primarily hydrogen gas—was likely stripped away by gravitational interactions with other galaxies inside the Perseus cluster.