NASA’s Hubble Space Telescope captured an uncommon sight – the death of a low-mass star – in this image of the Calabash Nebula released on Feb. 3, 2017.
Here, we can see the star going through a rapid transformation from a red giant to a planetary nebula, during which it blows its outer layers of gas and dust out into the surrounding space. The recently ejected material is spat out in opposite directions with immense speed — the gas shown in yellow is moving close to a million kilometers an hour.
Astronomers rarely capture a star in this phase of its evolution because it occurs within the blink of an eye – in astronomical terms. Over the next thousand years the nebula is expected to evolve into a fully-fledged planetary nebula.
NASA’s Nancy Grace Roman Space Telescope team has released detailed plans for a major survey that will reveal our home galaxy, the Milky Way, in unprecedented detail. In one month of observations spread across two years, the survey will unveil tens of billions of stars and explore previously uncharted structures.
This video begins with a view of the Carina Nebula — a giant, relatively nearby star-forming region in the southern sky. Roman will view the entire nebula as well as its surroundings, including a 10,000 light-year-long swath of the spiral arm it resides in. The observation will offer an unparalleled opportunity to watch how stars grow, interact, and sculpt their environments, and it’s just one of many thousands of highlights astronomers are looking forward to from the Galactic Plane Survey NASA’s Nancy Grace Roman Space Telescope will conduct. Credit: NASA’s Goddard Space Flight Center
“The Galactic Plane Survey will revolutionize our understanding of the Milky Way,” said Julie McEnery, Roman’s senior project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’ll be able to explore the mysterious far side of our galaxy and its star-studded heart. Because of the survey’s breadth and depth, it will be a scientific mother lode.”
The Galactic Plane Survey is Roman’s first selected general astrophysics survey — one of many observation programs Roman will do in addition to its three core surveys and Coronagraph technology demonstration. At least 25% of Roman’s five-year primary mission is reserved for astronomers worldwide to propose more surveys beyond the core programs, fully leveraging Roman’s capabilities to conduct groundbreaking science. Roman is slated to launch by May 2027, but the team is on track for launch as early as fall 2026.
While ESA’s (European Space Agency’s) retired Gaia spacecraft mapped around 2 billion Milky Way stars in visible light, many parts of the galaxy remain hidden by dust. By surveying in infrared light, Roman will use powerful heat vision that can pierce this veil to see what lies beyond.
“It blows my mind that we will be able to see through the densest part of our galaxy and explore it properly for the first time,” said Rachel Street, a senior scientist at Las Cumbres Observatory in Santa Barbara, California, and a co-chair of the committee that selected the Galactic Plane Survey design.
This infographic describes the 29-day Galactic Plane Survey that will be conducted by NASA’s Nancy Grace Roman Space Telescope. The survey’s main component will cover 691 square degrees — a region of sky as large as around 3,500 full moons — in 22.5 days. Roman will also view a smaller area — 19 square degrees, the area of 95 full moons — repeatedly for about 5.5 days total to capture things that change over time. The survey’s final component will image a smattering of even smaller areas, adding up to about 4 square degrees (the area of 20 full moons) and 31 total hours, with Roman’s full suite of filters and spectroscopic tools. The survey will reveal our home galaxy in unprecedented detail including many in regions we’ve never been able to see before because they’re blocked by dust, unveiling tens of billions of stars and other objects.
Credit: NASA’s Goddard Space Flight Center
The survey will cover nearly 700 square degrees (a region of sky as large as about 3,500 full moons) along the glowing band of the Milky Way — our edge-on view of the disk-shaped structure containing most of our galaxy’s stars, gas, and dust. Scientists expect the survey to map up to 20 billion stars and detect tiny shifts in their positions with repeated high-resolution observations. And it will only take 29 days spread over the course of the mission’s first two years.
Cosmic Cradles
Stars are born from parent clouds of gas and dust. Roman will peer through the haze of these nesting grounds to see millions of stellar embryos, newborn stars still swaddled in shrouds of dust, tantrumming toddler stars that flare unpredictably, and young stars that may have planetary systems forming around them. Astronomers will study stellar birth rates across a wide range of masses and stitch together videos that show how stars change over time.
“This survey will study such a huge number of stars in so many different stellar environments that we’ll be sampling every phase of a star’s evolution,” Street said.
Observing so many stars in various stages of early development will shed light on the forces that shape them. Star formation is like a four way tug-of-war between gravity, radiation, magnetism, and turbulence. Roman will help us study how these forces influence whether gas clouds collapse into full-fledged stars, smaller brown dwarfs — in-between objects that are much heavier than planets but not massive enough to ignite like stars — or new worlds.
The Galactic Plane Survey by NASA’s Nancy Grace Roman Space Telescope will scan the densest part of our galaxy, where most of its stars, gas, and dust reside — the most difficult region to study from our place inside the Milky Way since we have to look through so much light-blocking material. Roman’s wide field of view, crisp resolution, and infrared vision will help astronomers peer through thick bands of dust to chart new galactic territory. Credit: NASA’s Goddard Space Flight Center
Some stars are born in enormous litters called clusters. Roman will study nearly 2,000 young, loosely bound open clusters to see how the galaxy’s spiral arms trigger star formation. The survey will also map dozens of ancient, densely packed globular clusters near the center of the galaxy that could help astronomers reconstruct the Milky Way’s early history.
Comparing Roman’s snapshots of clusters scattered throughout the galaxy will enable scientists to study nature versus nurture on a cosmic scale. Because a cluster’s stars generally share the same age, origin, and chemical makeup, analyzing them allows astronomers to isolate environmental effects very precisely.
Pulse Check
When they run out of fuel, Sun-like stars leave behind cores called white dwarfs and heavier stars collapse to form neutron stars and black holes. Roman will find these stellar embers even when they’re alone thanks to wrinkles in space-time.
Anything that has mass warps the underlying fabric of the universe. When light from a background star passes through the gravitational well around an intervening object on its journey toward Earth, its path slightly curves around the object. This phenomenon, called microlensing, can temporarily brighten the star. By studying these signals, astronomers can learn the mass and size of otherwise invisible foreground objects.
A separate survey — Roman’s Galactic Bulge Time-Domain Survey — will conduct deep microlensing observations over a smaller area in the heart of the Milky Way. The Galactic Plane Survey will conduct repeated observations over a shorter interval but across the whole center of the galaxy, giving us the first complete view of this complex galactic environment. An unobscured view of the galaxy’s central bar will help astronomers answer the question of its origin, and Roman’s videos of stars in this region will enable us to study some ultratight binary objects at the very ends of their lives thanks to their interactions with close companions.
“Compact binaries are particularly interesting because they’re precursors to gravitational-wave sources,” said Robert Benjamin, a visiting professor at the University of Wisconsin-Whitewater, and a co-chair of the committee that selected the Galactic Plane Survey design. When neutron stars and black holes merge, the collision is so powerful that it sends ripples through the fabric of space-time. “Scientists want to know more about the pathways that lead to those mergers.”
optical
infrared
This colorful image, taken by the Hubble Space Telescope and published in 2018, celebrated the observatory’s 28th anniversary of viewing the heavens.
This colorful image, taken by the Hubble Space Telescope and published in 2018, celebrated the observatory’s 28th anniversary of viewing the heavens.
optical
infrared
Optical vs infrared
Two Views
The Galactic Plane Survey by NASA’s Nancy Grace Roman Space Telescope will scan the densest part of our galaxy, where most of its stars, gas, and dust reside — the most difficult region to study from our place inside the Milky Way since we have to look through so much light-blocking material. Roman’s wide field of view, crisp resolution, and infrared vision will help astronomers peer through thick bands of dust to chart new galactic territory. Credit: NASA, ESA, and STScI
Roman’s repeated observations will also monitor stars that flicker. Ground-based surveys detect thousands of bright stellar outbursts, but often can’t see the faint, dust-obscured stars that produce them. Roman will pinpoint the culprits plus take high-resolution snapshots of the aftermath.
Some stars throb rhythmically, and the speed of their pulsing is directly linked to their intrinsic brightness. By comparing their true brightness to how bright they appear from Earth, astronomers can measure distances across the galaxy. Roman will find these blinking stars farther away than ever before and track them over time, helping astronomers improve their cosmic measuring sticks.
“Pairing Roman’s Galactic Plane Survey with other Milky Way observations will create the best portrait of the galaxy we’ve ever had,” Benjamin said.
This NASA/ESA Hubble Space Telescope image features the blue dwarf galaxy Markarian 178 (Mrk 178) against a backdrop of distant galaxies in all shapes and sizes. Some of these distant galaxies even shine through the diffuse edges of Mrk 178.
ESA/Hubble & NASA, F. Annibali, S. Hong
This NASA/ESA Hubble Space Telescope image features a glittering blue dwarf galaxy called Markarian 178 (Mrk 178). The galaxy, which is substantially smaller than our own Milky Way, lies 13 million light-years away in the constellation Ursa Major (the Great Bear).
Mrk 178 is one of more than 1,500 Markarian galaxies. These galaxies get their name from the Armenian astrophysicist Benjamin Markarian, who compiled a list of galaxies that were surprisingly bright in ultraviolet light.
While the bulk of the galaxy is blue due to an abundance of young, hot stars with little dust shrouding them, Mrk 178 gets a red hue from a collection of rare massive Wolf–Rayet stars. These stars are concentrated in the brightest, reddish region near the galaxy’s edge. Wolf–Rayet stars cast off their atmospheres through powerful winds, and the bright emission lines from their hot stellar winds are etched upon the galaxy’s spectrum. Both ionized hydrogen and oxygen lines are particularly strong and appear as a red color in this photo.
Massive stars enter the Wolf–Rayet phase of their evolution just before they collapse into black holes or neutron stars. Because Wolf–Rayet stars last for only a few million years, researchers know that something must have triggered a recent burst of star formation in Mrk 178. At first glance, it’s not clear what could be the cause — Mrk 178 doesn’t seem to have any close galactic neighbors that may have stirred up its gas to form new stars. Instead, researchers suspect that a gas cloud crashed into Mrk 178, or that the intergalactic medium disturbed its gas as the galaxy moved through space. Either disturbance could light up this tiny galaxy with a ripple of bright new stars.
Waves of heavy rainfall in early December 2025 spurred landslides and flooding in parts of the Pacific Northwest. The deluge was the result of a potent atmospheric river that took aim at the region starting around December 7.
Atmospheric rivers are long, narrow bands of moisture that move like rivers in the sky, transporting water vapor from the tropics toward the poles. They occur around the planet, most often in autumn and winter, with the U.S. West Coast typically affected by moist air that originates near Hawaii. In this event, however, some of the moisture arrived from even farther away, originating roughly 7,000 miles (11,000 kilometers) across the Pacific from near the Philippines.
This map shows the total precipitable water vapor in the atmosphere at 11:30 p.m. Pacific Time on December 10. It is derived from NASA’s GEOS (Goddard Earth Observing System) and uses satellite data and models of physical processes to approximate what is happening in the atmosphere.
Precipitable water vapor represents the amount of water contained in a column of air, assuming all the water vapor condensed into liquid. The map’s green areas indicate the highest amounts of moisture. Note that not all precipitable water vapor falls as rain; at least some remains in the atmosphere. Nor is it a cap on how much rain can fall, since rainfall can increase as more moisture flows into a column of air. Still, it serves as a useful indicator of areas where excessive rainfall is likely.
According to the National Weather Service, preliminary ground-based measurements showed that several locations in western Washington received more than 10 inches (250 millimeters) of rain over a 72-hour period ending on the morning of December 11. Seattle-Tacoma International Airport set a daily rainfall record on December 10, with 1.6 inches (40 millimeters).
River flooding was ongoing on December 11, with the Skagit River and Snohomish River seeing record or near-record flood levels that day. Floodwater and mudslides have closed numerous roadways, including the eastbound lanes of I-90 out of western Washington.
NASA’s Disasters Response Coordination System has been activated to support the ongoing response efforts by the Washington State Emergency Operations Center. The team will be posting maps and data products on its open-access mapping portal as new information becomes available.
NASA Earth Observatory images by Lauren Dauphin, using GEOS data from the Global Modeling and Assimilation Office at NASA GSFC. Story by Kathryn Hansen.
¿Te has preguntado cómo los aviones han transformado el mundo en menos de un siglo? Desde vuelos transcontinentales hasta drones de reparto, las aeronaves siguen redefiniendo la movilidad humana y la logística global. Este artículo explora la tecnología, la seguridad y las tendencias que están modelando el futuro de la aviación con ejemplos prácticos y consejos útiles.
¿Cómo funcionan los aviones hoy en día?
Los aviones modernos combinan aerodinámica, propulsión y sistemas digitales avanzados. Los motores a reacción generan empuje mientras las alas proporcionan sustentación gracias al diseño del perfil aerodinámico.
Además, la aviónica —los sistemas electrónicos a bordo— controla la navegación, las comunicaciones y la gestión del vuelo. Estos avances hacen posible vuelos más eficientes y seguros en rutas cada vez más congestionadas.
Motores y eficiencia de combustible
Los nuevos motores turbofan reducen el consumo de combustible y las emisiones. Fabricantes como Rolls-Royce, GE y Pratt & Whitney invierten en materiales compuestos y turbinas de última generación.
Por otro lado, las mejoras en aerodinámica y en la gestión de combustible permiten trayectos más largos con menor impacto ambiental. Esto es clave para aerolíneas que buscan reducir costes y emisiones.
Sistemas de navegación y aviónica
La aviónica integra GPS, radar meteorológico y pilotos automáticos avanzados. Estas herramientas disminuyen la carga de trabajo de la tripulación y aumentan la precisión en rutas complejas.
Además, la conectividad en tiempo real facilita la coordinación con controladores aéreos y operaciones en tierra, mejorando la puntualidad y la seguridad.
Seguridad aérea: protocolos y mejoras tecnológicas
La seguridad sigue siendo la prioridad máxima en aviación comercial. Los procedimientos, el mantenimiento predictivo y la formación continua de las tripulaciones son pilares esenciales.
Asimismo, las inspecciones basadas en datos permiten detectar fallos antes de que ocurran, reduciendo riesgos y costes operativos.
Mantenimiento predictivo y análisis de datos
Los aviones actuales generan miles de parámetros por vuelo. Estos datos se analizan con inteligencia artificial para anticipar necesidades de mantenimiento.
Por consiguiente, las aerolíneas pueden programar revisiones más precisas y evitar cancelaciones inesperadas.
Tendencias emergentes en la aviación y aviones del futuro
La sostenibilidad, la electrificación y la automatización son tendencias que impulsan cambios profundos. Proyectos de aviones eléctricos y de hidrógeno ya están en fase de prueba.
Además, la integración de drones y taxis aéreos urbanos promete transformar la movilidad en las ciudades durante la próxima década.
Aviones eléctricos e híbridos
Las aeronaves eléctricas ofrecen vuelos más silenciosos y menos contaminantes en rutas cortas. Empresas emergentes y grandes fabricantes compiten por demostrar viabilidad comercial.
Sin embargo, los desafíos incluyen la densidad energética de las baterías y la infraestructura de recarga en aeropuertos.
Taxis aéreos y movilidad urbana
Los vehículos eléctricos de despegue y aterrizaje vertical (eVTOL) podrían resolver problemas de congestión urbana. Ciudades y reguladores ya estudian corredores aéreos seguros para estos servicios.
En consecuencia, la colaboración entre gobiernos y empresas privadas será clave para introducir estas soluciones sin comprometer la seguridad.
Cómo elegir vuelos y aviones para tus necesidades
Si viajas con frecuencia, considera la eficiencia de la aerolínea, la flota y la reputación en seguridad. Los aviones más nuevos suelen ofrecer mejor conectividad y menor consumo de combustible.
Además, compara rutas directas frente a escalas para optimizar tiempo y reduce tu huella de carbono eligiendo vuelos con menor consumo por pasajero.
Consejos prácticos para viajeros
Reserva con antelación para acceder a mejores tarifas y asientos. También revisa las políticas de equipaje y las opciones de compensación de emisiones.
Por último, mantente informado sobre las novedades en aviación para aprovechar mejoras en confort y seguridad.
Los aviones no solo conectan destinos, también conectan posibilidades tecnológicas y económicas. Siguiendo tendencias y adoptando prácticas responsables, pasajeros y operadores pueden beneficiarse de vuelos más eficientes y sostenibles. Actúa hoy comparando opciones de viaje, apoyando iniciativas limpias y eligiendo aerolíneas comprometidas con la innovación; así contribuirás a un futuro de la aviación más seguro y respetuoso con el planeta.
NASA has selected one small explorer mission concept to advance toward flight design and another for an extended period of concept development.
NASA’s Science Mission Directorate Science Management Council selected CINEMA (Cross-scale Investigation of Earth’s Magnetotail and Aurora) to enter Phase B of development, which includes planning and design for flight and mission operations. The principal investigator for the CINEMA mission concept is Robyn Millan from Dartmouth College in Hanover, New Hampshire.
The proposed CINEMA mission aims to advance our understanding of how plasma energy flows into the Earth’s magnetosphere. This highly dynamic convective flow is unpredictable — sometimes steady and sometimes explosive — driving phenomena like fast plasma jets, global electrical current systems, and spectacular auroral displays.
“The CINEMA mission will help us to research magnetic convection in Earth’s magnetosphere — a critical piece of the puzzle in understanding why some space weather events are so influential, such as causing magnificent aurora displays and impacts to ground- and space-based infrastructure, and others seem to fizzle out,” said Joe Westlake, director of the Heliophysics Division at NASA Headquarters in Washington. “Using multiple, multi-point measurements to improve predictions of these impacts on humans and technology across the solar system is a key strategy for the future of heliophysics research.”
The CINEMA mission’s constellation of nine small satellites will investigate the convective mystery using a combination of instruments — an energetic particle detector, an auroral imager, and a magnetometer — on each spacecraft in a polar low Earth orbit. By relating the energetic particles observed in this orbit to simultaneous auroral images and local magnetic field measurements, CINEMA aims to connect energetic activity in Earth’s large-scale magnetic structure to the visible signatures like aurora that we see in the ionosphere. The mission has been awarded approximately $28 million to enter Phase B. The total cost of the mission, not including launch, will not exceed $182.8 million. Phase B will last 10 months, and if selected, the mission would launch no earlier than 2030.
NASA also selected the proposed CMEx (Chromospheric Magnetism Explorer) mission for an extended Phase A study. This extended phase is for the mission to assess and refine their design for potential future consideration. The principal investigator for the CMEx mission concept study is Holly Gilbert from the National Center for Atmospheric Research in Boulder, Colorado. The cost of the extended Phase A, which will last 12 months, is $2 million.
The CMEx concept is a proposed single-spacecraft mission that would use proven UV spectropolarimetric instrumentation that has been demonstrated during NASA’s CLASP (Chromospheric Layer Spectropolarimeter) sub-orbital sounding rocket flight. Using this heritage hardware, CMEx would be able to diagnose lower layers of the Sun’s chromosphere to understand the origin of solar eruptions and determine the magnetic sources of the solar wind.
The proposed missions completed a one-year early concept study in response to the 2022 Heliophysics Explorers Program Small-class Explorer (SMEX) Announcement of Opportunity.
“Space is becoming increasingly more important and plays a role in just about everything we do,” said Asal Naseri, acting associate flight director for heliophysics at NASA Headquarters. “These mission concepts, if advanced to flight, will improve our ability to predict solar events that could harm satellites that we rely on every day and mitigate danger to astronauts near Earth, at the Moon, or Mars.”
To learn more about NASA heliophysics missions, visit:
Preparations for Next Moonwalk Simulations Underway (and Underwater)
The 2025 Boeing ecoDemonstrator Explorer, a United Airlines 737-8, sits outside a United hangar in Houston.
Boeing / Paul Weatherman
Picture this: You’re just about done with a transoceanic flight, and the tracker in your seat-back screen shows you approaching your destination airport. And then … you notice your plane is moving away. Pretty far away. You approach again and again, only to realize you’re on a long, circling loop that can last an hour or more before you land.
If this sounds familiar, there’s a good chance the delay was caused by issues with trajectory prediction. Your plane changed its course, perhaps altering its altitude or path to avoid weather or turbulence, and as a result its predicted arrival time was thrown off.
“Often, if there’s a change in your trajectory – you’re arriving slightly early, you’re arriving slightly late – you can get stuck in this really long, rotational holding pattern,” said Shivanjli Sharma, NASA’s Air Traffic Management–eXploration (ATM-X) project manager and the agency’s Ames Research Center in California’s Silicon Valley.
This inconvenience to travelers is also an economic and efficiency challenge for the aviation sector, which is why NASA has worked for years to study the issue, and recently teamed with Boeing to conduct real-time tests an advanced system that shares trajectory data between an aircraft and its support systems.
Boeing began flying a United Airlines 737 for about two weeks in October testing a data communication system designed to improve information flow between the flight deck, air traffic control, and airline operation centers. The work involved several domestic flights based in Houston, as well as flight over the Atlantic to Edinburgh, Scotland.
This partnership has allowed NASA to further its commitment to transformational aviation research.
Shivanjli sharma
NASA’s Air Traffic Management—eXploration project manager
The testing was Boeing’s most recent ecoDemonstrator Explorer program, through which the company works with public and private partners to accelerate aviation innovations. This year’s ecoDemonstrator flight partners included NASA, the Federal Aviation Administration, United Airlines, and several aerospace companies as well as academic and government researchers.
NASA’s work in the testing involved the development of an oceanic trajectory prediction service – a system for sharing and updating trajectory information, even over a long, transoceanic flight that involves crossing over from U.S. air traffic systems into those of another country. The collaboration allowed NASA to get a more accurate look at what’s required to reduce gaps in data sharing.
“At what rate do you need these updates in an oceanic environment?” Sharma said. “What information do you need from the aircraft? Having the most accurate trajectory information will allow aircraft to move more efficiently around the globe.”
Boeing and the ecoDemonstrator collaborators plan to use the flight data to move the data communication system toward operational service. The work has allowed NASA to continue its work to improve trajectory prediction, and through its connection with partners, put its research into practical use as quickly as possible.
“This partnership has allowed NASA to further its commitment to transformational aviation research,” Sharma said. “Bringing our expertise in trajectory prediction together with the contributions of so many innovative partners contributes to global aviation efficiency that will yield real benefits for travelers and industry.”
NASA ATM-X’s part in the collaboration falls under the agency’s Airspace Operations and Safety Program, which works to enable safe, efficient aviation transportation operations that benefit the flying public and industry. The work is supported through NASA’s Aeronautics Research Mission Directorate.
NGC 6278 and PGC 039620 are two galaxies from a sample of 1,600 that were searched for the presence of supermassive black holes. These images represent the results of a study that suggests that smaller galaxies do not contain supermassive black holes nearly as often as larger galaxies do. The study analyzed over 1,600 galaxies that have been observed with Chandra over two decades. Certain X-ray signatures indicate the presence of supermassive black holes. The study indicates that most smaller galaxies like PGC 03620, shown here in both X-rays from Chandra and optical light images from the Sloan Digital Sky Survey, likely do not have supermassive black holes in their centers. In contrast, NGC 6278, which is roughly the same size as the Milky Way, and most other large galaxies in the sample show evidence for giant black holes within their cores.
X-ray: NASA/CXC/SAO/F. Zou et al.; Optical: SDSS; Image Processing: NASA/CXC/SAO/N. Wolk
Most smaller galaxies may not have supermassive black holes in their centers, according to a recent study using NASA’s Chandra X-ray Observatory. This contrasts with the common idea that nearly every galaxy has one of these giant black holes within their cores, as NASA leads the world in exploring how our universe works.
A team of astronomers used data from over 1,600 galaxies collected in more than two decades of the Chandra mission. The researchers looked at galaxies ranging in heft from over ten times the mass of the Milky Way down to dwarf galaxies, which have stellar masses less than a few percent of that of our home galaxy. A paper describing these results has been published in The Astrophysical Journal and is available here https://arxiv.org/abs/2510.05252.
The team has reported that only about 30% of dwarf galaxies likely contain supermassive black holes.
“It’s important to get an accurate black hole head count in these smaller galaxies,” said Fan Zou of the University of Michigan in Ann Arbor, who led the study. “It’s more than just bookkeeping. Our study gives clues about how supermassive black holes are born. It also provides crucial hints about how often black hole signatures in dwarf galaxies can be found with new or future telescopes.”
As material falls onto black holes, it is heated by friction and produces X-rays. Many of the massive galaxies in the study contain bright X-ray sources in their centers, a clear signature of supermassive black holes in their centers. The team concluded that more than 90% of massive galaxies – including those with the mass of the Milky Way – contain supermassive black holes.
However, smaller galaxies in the study usually did not have these unambiguous black hole signals. Galaxies with masses less than three billion Suns – about the mass of the Large Magellanic Cloud, a close neighbor to the Milky Way – usually do not contain bright X-ray sources in their centers.
The researchers considered two possible explanations for this lack of X-ray sources. The first is that the fraction of galaxies containing massive black holes is much lower for these less massive galaxies. The second is the amount of X-rays produced by matter falling onto these black holes is so faint that Chandra cannot detect it.
“We think, based on our analysis of the Chandra data, that there really are fewer black holes in these smaller galaxies than in their larger counterparts,” said Elena Gallo, a co-author also from the University of Michigan.
To reach their conclusion, Zou and his colleagues considered both possibilities for the lack of X-ray sources in small galaxies in their large Chandra sample. The amount of gas falling onto a black hole determines how bright or faint they are in X-rays. Because smaller black holes are expected to pull in less gas than larger black holes, they should be fainter in X-rays and often not detectable. The researchers confirmed this expectation.
However, they found that an additional deficit of X-ray sources is seen in less massive galaxies beyond the expected decline from decreases in the amount of gas falling inwards. This additional deficit can be accounted for if many of the low-mass galaxies simply don’t have any black holes at their centers. The team’s conclusion was that the drop in X-ray detections in lower mass galaxies reflects a true decrease in the number of black holes located in these galaxies.
This result could have important implications for understanding how supermassive black holes form. There are two main ideas: In the first, a giant gas cloud directly collapses into a black hole, which contains thousands of times the Sun’s mass from the start. The other idea is that supermassive black holes instead come from much smaller black holes, created when massive stars collapse.
“The formation of big black holes is expected to be rarer, in the sense that it occurs preferentially in the most massive galaxies being formed, so that would explain why we don’t find black holes in all the smaller galaxies,” said co-author Anil Seth of the University of Utah.
This study supports the theory where giant black holes are born already weighing several thousand times the Sun’s mass. If the other idea were true, the researchers said they would have expected smaller galaxies to likely have the same fraction of black holes as larger ones.
This result also could have important implications for the rates of black hole mergers from the collisions of dwarf galaxies. A much lower number of black holes would result in fewer sources of gravitational waves to be detected in the future by the Laser Interferometer Space Antenna. The number of black holes tearing stars apart in dwarf galaxies will also be smaller.
NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.
NASA’s Parker Solar Probe Spies Solar Wind ‘U-Turn’
Images captured by NASA’s Parker Solar Probe as the spacecraft made its record-breaking closest approach to the Sun in December 2024 have now revealed new details about how solar magnetic fields responsible for space weather escape from the Sun — and how sometimes they don’t.
Like a toddler, our Sun occasionally has disruptive outbursts. But instead of throwing a fit, the Sun spews magnetized material and hazardous high-energy particles that drive space weather as they travel across the solar system. These outbursts can impact our daily lives, from disrupting technologies like GPS to triggering power outages, and they can also imperil voyaging astronauts and spacecraft. Understanding how these solar outbursts, called coronal mass ejections (CMEs), occur and where they are headed is essential to predicting and preparing for their impacts at Earth, the Moon, and Mars.
Images taken by Parker Solar Probe in December 2024, and published Thursday in the Astrophysical Journal Letters, have revealed that not all magnetic material in a CME escapes the Sun — some makes it back, changing the shape of the solar atmosphere in subtle, but significant, ways that can set the course of the next CME exploding from the Sun. These findings have far-reaching implications for understanding how the CME-driven release of magnetic fields affects not only the planets, but the Sun itself.
These images from the Wide-Field Imager for Solar Probe on NASA’s Parker Solar Probe show a phenomenon that occurs in the Sun’s upper atmosphere called an inflow. Inflows are the result of stretched magnetic field lines reconfiguring and causing material trapped along the lines to rain back toward the solar surface.
NASA
“These breathtaking images are some of the closest ever taken to the Sun and they’re expanding what we know about our closest star,” said Joe Westlake, heliophysics division director at NASA Headquarters in Washington. “The insights we gain from these images are an important part of understanding and predicting how space weather moves through the solar system, especially for mission planning that ensures the safety of our Artemis astronauts traveling beyond the protective shield of our atmosphere.”
Parker Solar Probe reveals solar recycling in action
As Parker Solar Probe swept through the Sun’s atmosphere on Dec. 24, 2024, just 3.8 million miles from the solar surface, its Wide-Field Imager for Solar Probe, or WISPR, observed a CME erupt from the Sun. In the CME’s wake, elongated blobs of solar material were seen falling back toward the Sun.
This type of feature, called “inflows”, has previously been seen from a distance by other NASA missions including SOHO (Solar and Heliospheric Observatory, a joint mission with ESA, the European Space Agency) and STEREO (Solar Terrestrial Relations Observatory). But Parker Solar Probe’s extreme close-up view from within the solar atmosphere reveals details of material falling back toward the Sun and on scales never seen before.
“We’ve previously seen hints that material can fall back into the Sun this way, but to see it with this clarity is amazing,” said Nour Rawafi, the project scientist for Parker Solar Probe at the Johns Hopkins Applied Physics Laboratory, which designed, built, and operates the spacecraft in Laurel, Maryland. “This is a really fascinating, eye-opening glimpse into how the Sun continuously recycles its coronal magnetic fields and material.”
Insights on inflows
For the first time, the high-resolution images from Parker Solar Probe allowed scientists to make precise measurements about the inflow process, such as the speed and size of the blobs of material pulled back into the Sun. These previously hidden details provide scientists with new insights into the physical mechanisms that reconfigure the solar atmosphere.
1. The process that creates inflows begins with a solar eruption known as a coronal mass ejection (CME). CMEs are often triggered by twisted magnetic field lines from the Sun that explosively snap and realign in a process called magnetic reconnection. This magnetic explosion kicks out a burst of charged particles and magnetic fields — the CME.
NASA
2.As the CME travels outward from the Sun, the CME expands. Eventually, it pushes through solar magnetic field lines to escape into space.
NASA
3. The magnetic field lines torn open by the CME rejoin to form new magnetic loops that get squeezed together.
NASA
4. In some cases, the compressed magnetic field lines tear apart. This forms separate magnetic loops, some of which travel outward from the Sun and others that connect back to the Sun. As these loops contract back into the Sun, they drag down blobs of nearby solar material — forming inflows.
NASA
The CMEs are often triggered by twisted magnetic field lines that explosively snap and realign in a process called magnetic reconnection. This magnetic explosion kicks out a burst of charged particles and magnetic fields — a CME.
As the CME travels outward from the Sun, it expands, in some cases causing nearby magnetic field lines to tear apart like the threads of an old piece of cloth pulled too tight. The torn magnetic field quickly mends itself, creating separate magnetic loops. Some of the loops travel outward from the Sun, and others stitch back to the Sun, forming inflows.
“It turns out, some of the magnetic field released with the CME does not escape as we would expect,” said Angelos Vourlidas, WISPR project scientist and researcher at Johns Hopkins Applied Physics Laboratory. “It actually lingers for a while and eventually returns to the Sun to be recycled, reshaping the solar atmosphere in subtle ways.”
An important result of this magnetic recycling is that as the inflows contract back into the Sun, they drag down blobs of nearby solar material and ultimately affect the magnetic fields swirling beneath. This interaction reconfigures the solar magnetic landscape, potentially altering the trajectories of subsequent CMEs that may emerge from the region.
“The magnetic reconfiguration caused by inflows may be enough to point a secondary CME a few degrees in a different direction,” Vourlidas said. “That’s enough to be the difference between a CME crashing into Mars versus sweeping by the planet with no or little effects.”
Scientists are using the new findings to improve their models of space weather and the Sun’s complex magnetic environment. Ultimately, this work may help scientists better predict the impact of space weather across the solar system on longer timescales than currently possible.
“Eventually, with more and more passes by the Sun, Parker Solar Probe will help us be able to continue building the big picture of the Sun’s magnetic fields and how they can affect us,” Rawafi said. “And as the Sun transitions from solar maximum toward minimum, the scenes we’ll witness may be even more dramatic.”
By Mara Johnson-Groh NASA’s Goddard Space Flight Center, Greenbelt, Md.
NASA, ESA, CSA, STScI, Yu Cheng (NAOJ); Image Processing: Joseph DePasquale (STScI)
NASA’s James Webb Space Telescope captured a blowtorch of seething gasses erupting from a volcanically growing monster star in this image released on Sept. 10, 2025. Stellar jets, which are powered by the gravitational energy released as a star grows in mass, encode the formation history of the protostar. This image provides evidence that protostellar jets scale with the mass of their parent stars—the more massive the stellar engine driving the plasma, the larger the resulting jet.
Image credit: NASA, ESA, CSA, STScI, Yu Cheng (NAOJ); Image Processing: Joseph DePasquale (STScI)
