Category: 7. Science

The Milky Way may be surrounded by dozens of yet-to-be-detected satellite galaxies, scientists claim.

Using the highest-resolution simulation of our galaxy’s dark matter — an invisible entity that shapes the large-scale structure of the universe — and new mathematical models, cosmologists predict that more than 100 additional satellite galaxies beyond the ones already cataloged may be swirling around our own.

The National Academy of Sciences (NAS) has elected 120 members and 30 international members, including five MIT faculty members and 13 MIT alumni. Professors Rodney Brooks, Parag Pathak, Scott Sheffield, Benjamin Weiss, and Yukiko Yamashita were elected in recognition of their “distinguished and continuing achievements in original research.” Membership to the National Academy of Sciences is one of the highest honors a scientist can receive in their career.

Elected MIT alumni include: David Altshuler ’86, Rafael Camerini-Otero ’66, Kathleen Collins PhD ’92, George Daley PhD ’89, Scott Doney PhD ’91, John Doyle PhD ’91, Jonathan Ellman ’84, Shanhui Fan PhD ’97, Julia Greer ’97, Greg Lemke ’78, Stanley Perlman PhD ’72, David Reichman PhD ’97, and Risa Wechsler ’96. 

Those elected this year bring the total number of active members to 2,662, with 556 international members. The NAS is a private, nonprofit institution that was established under a congressional charter signed by President Abraham Lincoln in 1863. It recognizes achievement in science by election to membership, and — with the National Academy of Engineering and the National Academy of Medicine — provides science, engineering, and health policy advice to the federal government and other organizations.

Rodney Brooks

Rodney A. Brooks is the Panasonic Professor of Robotics Emeritus at MIT and the chief technical officer and co-founder of Robust AI. Previously, he was founder, chair, and CTO of Rethink Robotics and founder and CTO of iRobot Corp. He is also the former director of the MIT Artificial Intelligence Laboratory and the MIT Computer Science and Artificial Intelligence Laboratory. Brooks received degrees in pure mathematics from the Flinders University of South Australia and a PhD in computer science from Stanford University in 1981. He held research positions at Carnegie Mellon University and MIT, and a faculty position at Stanford before joining the faculty of MIT in 1984.

Brooks’ research is concerned with both the engineering of intelligent robots to operate in unstructured environments, and with understanding human intelligence through building humanoid robots. He has published papers and books in model-based computer vision, path planning, uncertainty analysis, robot assembly, active vision, autonomous robots, micro-robots, micro-actuators, planetary exploration, representation, artificial life, humanoid robots, and compiler design.

Brooks is a member of the National Academy of Engineering, a founding fellow of the Association for the Advancement of Artificial Intelligence, a fellow of the American Academy of Arts and Sciences, the American Association for the Advancement of Science, the Association for Computing Machinery, a foreign fellow of The Australian Academy of Technological Sciences and Engineering, and a corresponding member of the Australian Academy of Science. He won the Computers and Thought Award at the 1991 International Joint Conference on Artificial Intelligence, and the IEEE Founders Medal in 2023.

Parag Pathak

Parag Pathak is the Class of 1922 Professor of Economics and a founder and director of MIT’s Blueprint Labs. He joined the MIT faculty in 2008 after completing his PhD in business economics and his master’s and bachelor’s degrees in applied mathematics, all at Harvard University.

Pathak is best known for his work on market design and education. His research has informed student placement and school choice mechanisms across the United States, including in Boston, New York City, Chicago, and Washington, and his recent work applies ideas from market design to the rationing of vital medical resources. Pathak has also authored leading studies on school quality, charter schools, and affirmative action. In urban economics, he has measured the effects of foreclosures on house prices and how the housing market reacted to the end of rent control in Cambridge, Massachusetts.

Pathak’s research on market design was recognized with the 2018 John Bates Clark Medal, given by the American Economic Association to the economist under 40 whose work is judged to have made the most significant contribution to the field. He is a fellow of the American Academy of Arts and Sciences, the Econometric Society, and the Society for the Advancement of Economic Theory. Pathak is also the founding co-director of the market design working group at the National Bureau of Economic Research, and a co-founder of Avela Education.

Scott Sheffield

Scott Sheffield, Leighton Family Professor of Mathematics, joined the MIT faculty in 2008 after a faculty appointment at the Courant Institute at New York University. He received a PhD in mathematics from Stanford University in 2003 under the supervision of Amir Dembo, and completed BA and MA degrees in mathematics from Harvard University in 1998.

Sheffield is a probability theorist, working on geometrical questions that arise in such areas as statistical physics, game theory, and metric spaces, as well as long-standing problems in percolation theory and the theory of random surfaces.

In 2017, Sheffield received the Clay Research Award with Jason Miller, “in recognition of their groundbreaking and conceptually novel work on the geometry of Gaussian free field and its application to the solution of open problems in the theory of two-dimensional random structures.” In 2023, he received the Leonard Eisenbud Prize with Jason Miller “for works on random two-dimensional geometries, and in particular on Liouville Quantum Gravity.” Later in 2023, Sheffield received the Frontiers of Science Award with Jason Miller for the paper “Liouville quantum gravity and the Brownian map I: the QLE(8/3,0) metric.” Sheffield is a fellow of the American Academy of Arts and Science.

Benjamin Weiss

Benjamin Weiss is the Robert R. Schrock Professor of Earth and Planetary Sciences. He studied physics at Amherst College as an undergraduate and went on to study planetary science and geology at Caltech, where he earned a master’s degree in 2001 and PhD in 2003. Weiss’ doctoral dissertation on Martian meteorite ALH 84001 revealed records of the ancient Martian climate and magnetic field, and provided evidence some meteorites could transfer materials from Mars to Earth without heat-sterilization. Weiss became a member of the Department of Earth, Atmospheric and Planetary Sciences faculty in 2004 and is currently chair of the Program in Planetary Science.

A specialist in magnetometry, Weiss seeks to understand the formation and evolution of the Earth, terrestrial planets, and small solar system bodies through laboratory analysis, spacecraft observations, and fieldwork. He is known for key insights into the history of our solar system, including discoveries about the early nebular magnetic field, the moon’s long-lived core dynamo, and asteroids that generated core dynamos in the past. In addition to leadership roles on current, active NASA missions — as deputy principal investigator for Psyche, and co-investigator for Mars Perseverance and Europa Clipper — Weiss has also been part of science teams for the SpaceIL Beresheet, JAXA Hayabusa 2, and ESA Rosetta spacecraft.

As principal investigator of the MIT Planetary Magnetism Laboratory, Weiss works to develop high-sensitivity, high-resolution techniques in magnetic microscopy to image the magnetic fields embedded in rock samples collected from meteorites, the lunar surface, and sites around the Earth. Studying these magnetic signatures can help answer questions about the conditions of the early solar system, past climates on Earth and Mars, and factors that promote habitability.

Yukiko Yamashita

Yukiko Yamashita is a professor of biology at MIT, a core member of the Whitehead Institute for Biomedical Research, and an investigator at the Howard Hughes Medical Institute (HHMI). Yamashita earned her BS in biology in 1994 and her PhD in biophysics in 1999 from Kyoto University. From 2001 to 2006, she did postdoctoral research at Stanford University. She was appointed to the University of Michigan faculty in 2007 and was named an HHMI Investigator in 2014. She became a member of the Whitehead Institute and a professor of biology at MIT in 2020.

Yukiko Yamashita studies two fundamental aspects of multicellular organisms: how cell fates are diversified via asymmetric cell division, and how genetic information is transmitted through generations via the germline.

Two remarkable feats of multicellular organisms are generation of many distinct cell types via asymmetric cell division and transmission of the germline genome to the next generation, essentially in eternity. Studying these processes using the Drosophila male germline as a model system has led us to venture into new areas of study, such as functions of satellite DNA, “genomic junk,” and how they might be involved in speciation.

Yamashita is a member of the American Academy of Arts and Sciences, a fellow of the American Society for Cell Biology, and the winner of the Tsuneko and Reiji Okazaki Award in 2016. She was named a MacArthur Fellow in 2011.

NASA has been slowly working the Parker Solar Probe closer and closer to the Sun ever since its launch in 2018. The probe, which is heralded as the fastest object humans have ever made, has broken several records along the way. Now, it looks like NASA has used the probe to take the closest images of the Sun ever taken.

Each year since its launch, the Parker Solar Probe has been inching closer and closer to the star at the center of our solar system. While it has essentially touched the Sun at this point, the probe has now passed even closer, coming within just 3.8 million miles of the center of our solar system back in December. On this historically close flyby, the probe took more images of the Sun’s atmosphere.

At this point, the probe is basically traveling inside the Sun’s corona. It has touched the Sun and continues to fly without issue. It’s not only a testament to human invention and innovation, but it’s also to how far humans will go to learn more about the universe. There are, of course, myriad reasons why taking the closest images of the Sun possible is important. Most of all, though, they could help us better understand our Sun’s volatile activity.

One of the big hopes with Parker’s continued success is that we’ll be able to learn more about the solar atmosphere. This could help us eventually discover new ways to predict solar activity like coronal mass ejections (CMEs), solar flares, and more. Furthering this research could help us mitigate the effects of those dangerous solar eruptions, and perhaps even come up with better protections against the energy as a whole — something vitally important for any future spacecraft traveling outside the protection of Earth’s magnetic field.

These new images were taken by Parker’s Wide-Field Imager, which has proven to be a incredibly useful for capturing stills around our Sun. The imager views space in visible light, which means it sees things exactly the same way the human eye would. This removes any possibility for incorrect interpretation of the visuals seen in the images it takes.

But what makes the imager especially effective is that it isn’t pointed directly at the Sun. Instead, Parker’s Wide-Field Imager captures solar material as it comes off the Sun. This allows scientists to get an up-close-and-personal look at the origin of the solar wind that fills our solar system.

NIMS has developed a new theory that explains why tunnel magnetoresistance (TMR) —used in magnetic memory and other technologies— oscillates with changes in the thickness of the insulating barrier within a magnetic tunnel junction (MTJ). This oscillation was clearly observed when NIMS recently recorded the world’s highest TMR ratio. Understanding the mechanisms behind this phenomenon is expected to significantly aid in further increasing TMR ratios. This research was published as a letter article in Physical Review B, a journal of the American Physical Society, on June 9, 2025.

Background

The TMR effect is a phenomenon observed in thin-film structures called magnetic tunnel junctions (MTJs). It refers to changes in electrical resistance depending on the relative alignment of magnetizations in two magnetic layers (i.e., parallel or antiparallel alignment) separated by an insulating barrier. It is desirable to develop MTJs with larger TMR effects —reflected in higher TMR ratios— in order to expand their potential applications, including improvement of magnetic sensor sensitivity and expansion of magnetic memory capacity. A NIMS research team recently achieved the world’s highest TMR ratio, and also found that the TMR ratio oscillates by changing a thickness of the insulating barrier, referred to as the TMR oscillation. This finding indicates that understanding the physical origin of the TMR oscillation is vital to achieving even higher TMR ratios. However, the mechanism responsible for the TMR oscillation had remained unknown despite extensive research conducted on the subject for more than two decades.

Key Findings

The present research team developed a new theory for the TMR oscillation by considering a mechanism that had been overlooked in previous theoretical studies. Interfaces between magnetic layers and the insulating barrier in MTJs have been believed to play an important role in the TMR effect. The team took into account a superposition of wave functions between majority- and minority-spin states occurring at such an interface (Figure (a))—the most important and novel contribution made by this study. TMR ratios calculated using this theory were consistent with TMR ratios obtained experimentally, supporting the validity of the present theory (Figure (b)).

Future Outlook

Previous experiments for the TMR oscillation were conducted using MTJs with limited types of magnetic materials (e.g., iron). Future experimental studies using a broader range of magnetic materials may further advance the understanding of the TMR oscillation by comparing the results with the present theory. In addition, the present theory is expected to contribute to the development of guidelines for the control of the TMR oscillation and the design of MTJs with even higher TMR ratios.

Other Information

• This project was carried out by a research team consisting of Keisuke Masuda (Senior Researcher, Spin Theory Group (STG), Research Center for Magnetic and Spintronic Materials (CMSM), NIMS), Yoshio Miura (Invited Researcher, STG, CMSM, NIMS), Thomas Scheike (Guest Researcher, Spintronics Group (SG), CMSM, NIMS), Hiroaki Sukegawa (Leader, SG, CMSM, NIMS), Seiji Mitani (Managing Researcher, SG, CMSM, NIMS) and Yusuke Kozuka (Leader, Qubit Materials Group, Research Center for Materials Nanoarchitectonics, NIMS).
• This work was funded by the JSPS Grant-in-Aid for Scientific Research (grant numbers: 22H04966, 23K03933 and 24H00408) and the MEXT DxMT project (grant number: JPMXP1122715503)
• This research was published as a letter article in the online version of Physical Review B on June 9, 2025 and was selected as “Editors’ Suggestion”.

Heads up stargazers! The moon will rise close to Saturn and the ice giant Neptune in the eastern sky on the night of July 15, close enough to be seen together in a pair of binoculars!

Saturn will rise above the eastern horizon beneath the stars of the constellation Pisces shortly before midnight for viewers in the U.S. on July 15, with the waning gibbous moon shining roughly three degrees to its upper right. For context, the width of your little finger held at arms length against the night sky accounts for roughly 1 degree.

Canadians may think they’re intimately familiar with ice in all its forms, but there is one kind that most have probably never heard of. Clathrate hydratesare tiny crystalline cages of ice that can trap other gases or liquids inside them.

These hydrates can form in natural gas pipelines and cause explosions if they block the line. The BP Deepwater Horizon disaster in the Gulf of Mexico in 2010 was caused by hydrate formation, says John Tse, Canada Research Chair of Materials Science and a professor in the Department of Physics and Engineering Physics at the University of Saskatchewan.

That’s one of the reasons Tse and his colleagues “want to understand more about how this compound forms and how the gas and water interact with each other.”

Because the reactions that form hydrates happen so quickly, the researchers needed a way to both slow them down and observe them in progress. So Tse cooled down a mixture of water and a chemical called tetrahydrofuran (THF) to −263°C in a vacuum then used the powerful X-ray beamlines of the Canadian Light Source at the University of Saskatchewan to watch how the molecules moved and changed shape as he slowly warmed up the mixture.

Tse found that, as the temperature rose, the THF separated out and formed crystals while the frozen water remained in a noncrystal form. Then, around −163°C, the THF suddenly melted and mixed with the water to form clathrate hydrates, crystalline cages of ice with THF trapped inside.

Understanding more about how hydrates behave could lead to many different practical applications beyond just protecting against pipeline explosions. They could also be used in natural gas transport and storage—a single cubic foot of hydrate can store up to 150 cubic feet of gas—or for carbon capture and storage projects. Tse said he hopes that his fundamental science work will be used by more applications-minded engineers to develop helpful new technologies.

“Everything in science is baby steps,” Tse said. “We start with idealistic conditions and go toward practical ends. Someone might pick this up with a smart idea that relies on fundamental knowledge about how hydrates are formed.”

A new study has found that night lizards, small reptiles that inhabit North and Central America, survived the extinction event that wiped out most life on Earth—despite living near ground zero.

The asteroid strike 66 million years ago caused a mass extinction that wiped out 75% of Earth’s animal species, including all non-avian dinosaurs.

The new study has found that the oldest common ancestor of today’s xantusiid night lizards—small lizards that, despite their name, are most active during the day—predates the Cretaceous–Paleogene (K-Pg) extinction event. And they endured despite living in ecosystems within and near the Yucatan Peninsula, the site of the asteroid impact.

The study challenges prevailing hypotheses concerning the life history traits associated with surviving mass extinctions, the researchers say.

“We show that xantusiid night lizards are the only living family of terrestrial vertebrates known to survive of the K–Pg mass extinction in proximity to where the asteroid struck,” says Chase Brownstein, a student in Yale’s Graduate School of Arts and Sciences, in the ecology and evolutionary biology department, and the study’s lead author.

“This is especially interesting because night lizards don’t fit neatly into the conventional understanding of how to survive a mass extinction. For example, they have small litter sizes of one or two individuals when it’s widely believed that having a lot of offspring enhances the chances of survival.”

The study in the journal Biology Letters originated in a seminar co-taught by Yale professors Thomas Near and Martha Muñoz that focused on large-scale evolutionary changes to squamates, the order of reptiles that includes lizards and snakes.

“This paper demonstrates that when faculty members collaborate on teaching a class, exciting research can result,” says Near, professor of ecology and evolutionary biology in Yale’s Faculty of Arts and Sciences (FAS), and a coauthor of the study.

“In this case, it gave students like Chase an opportunity to pursue interesting research and also brought together two labs that don’t always have the chance to work together.”

Muñoz, associate professor of ecology and evolutionary biology in FAS, also coauthored the study.

Xantusiid night lizards are a species-poor lineage (an evolutionary lineage with relatively few living species) with conserved anatomy, meaning their anatomical features have remained relatively unchanged over evolutionary time across species. Despite their name, night lizards are most active during the day and at twilight. They live in microhabitats—small-scale environments, such as rock crevices or decaying logs, with unique properties from the surrounding ecosystem.

For their analysis, the researchers created a time-calibrated evolutionary tree using a technique called Bayesian tip-dating, which combines molecular genetic data with fossil specimens. They used DNA data for seven nuclear genes stored in GenBank, a database of all publicly available DNA sequences maintained by the US National Institutes of Health.

The researchers placed fossils at the tips of the tree’s branches, which helped to calibrate time. They restricted the analysis to nuclear genetic data (which is extracted from the nucleus of cells) as opposed to mitochondrial data (genetic information contained in the “powerhouse” of the cells), which prior research has shown artificially inflates estimates of when species diverged, the researchers note.

Night lizards have been endemic to North and Central America since the early stages of the Late Cretaceous, about 92 million years ago, according to the analysis. The results support the hypothesis that at least two lineages of night lizards persisted through the K–Pg extinction event, the researchers say.

By integrating life history data from living night lizard species, the researchers showed that the night lizard ancestors that witnessed the asteroid impact likely produced litter or clutch sizes of one or two babies.

The researchers don’t speculate on how the night lizards managed to survive the asteroid impact, but their findings suggest that the factors that facilitated survival are more complicated than previously thought.

“They were literally living within blast radius,” Brownstein says. “It’s interesting to consider how they survived. I think our findings suggest that no particular set of traits is necessarily the ‘best’ for surviving extinction. Certainly, some traits must be advantageous, it’s just difficult to know which and why.”

The study underscores the importance of GenBank and other federally maintained databases in supporting scientific inquiry, says Near, who is also the Bingham Oceanographic Curator of Ichthyology at the Yale Peabody Museum.

“GenBank and other federal repositories fuel curiosity-based science,” he says. “They are public libraries of vast amounts of information that allow scientists to perform research without needing to obtain large grants. They’re invaluable to improving our understanding of the world.”

Additional coauthors are from Yale and Ciudad Universitaria in Coyoacán, Mexico.

Source: Yale

Scientists have found that Uranus is emitting its own internal heat — even more than it receives from sunlight — and this discovery contradicts observations of the distant gas giant made by NASA’s Voyager 2 probe nearly four decades ago.

Scientists led by Xinyue Yang of the University of Houston analyzed decades of readings from spacecraft and computer models to find that Uranus emits 12.5% more internal heat than the amount of heat it receives from the sun. However, that amount is still far less than the internal heat of other outer solar system planets like Jupiter, Saturn and Neptune, which emit 100% more heat than they get from the sun.