Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Globular Cluster Omega Centauri
Explanation: Globular star cluster Omega Centauripacks about 10 million stars much older than the Sun into a volume some 150 light-years in diameter. Also known as NGC 5139, at a distance of 15,000 light-years it’s the largest and brightest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. Though most star clusters consist of stars with the same age and composition, the enigmatic Omega Cen exhibits the presence of different stellar populations with a spread of ages and chemical abundances. In fact, Omega Cen may be the remnant core of a small galaxy merging with the Milky Way. With a yellowish hue, Omega Centauri’s red giant stars are easy to pick out in this sharp telescopic view. A two-decade-long exploration of the dense star cluster with the Hubble Space Telescope has revealed evidence for a massive black hole near the center of Omega Centauri.
After rapidly intensifying, Hurricane Polo spins off Mexico’s Pacific coast on September 23, 2026 (left), over unusually warm waters (right). NASA Earth Observatory images by Michala Garrison, using data from the MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA’s Aqua satellite and the MUR SST (Multiscale Ultrahigh Resolution Sea Surface Temperature) project.
In mid-September 2026, Hurricane Polo began as a tropical disturbance off the Pacific coast of Mexico. By September 20, it was organized enough to qualify as a tropical depression, and by the next day it was a tropical storm.
From there, Polo launched into a period of rapid intensification that left meteorologists searching for adjectives strong enough to convey what was happening. Some described the storm’s rate of intensification and strength as “jaw-dropping,” others as “astonishing,”and others as “absolute insanity.”
“Polo went through a period of what can only be described as explosively rapid intensification,” said Gary Partyka, an atmospheric scientist with the Global Modeling and Assimilation Office (GMAO) at NASA’s Goddard Space Flight Center, in an email. “This was RAPID, rapid intensification.”
The storm was in an environment that was “near perfect” for strengthening, Partyka said, characterized by weak wind shear, high moisture, warmer ocean temperatures, and high levels of atmospheric instability.
Several observers leaned on extreme rapid intensification—a technical classification meaning the storm’s wind speeds increased at least 60 knots (111 kilometers or 69 miles per hour) within a 24-hour period. By September 22, the storm’s maximum sustained wind speed had risen by 90 knots (167 kilometers per hour or 104 miles per hour) within 24 hours, hitting category 5 strength. In its normally staid forecast discussions, the National Hurricane Center called the intensification “truly remarkable.”
When NOAA’s Hurricane Hunter aircraft flew over the storm on September 22, researchers estimated winds of nearly 285 kilometers (180 miles) per hour. That would make it the third-strongest storm on record in the eastern Pacific by maximum sustained winds and the fastest on record to go from a tropical depression to a category 5 storm, according to some analysts.
On the afternoon of September 23, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this image (left), Polo was churning off the coast of Guerrero, southwest of Acapulco. With maximum sustained winds of 230 kilometers (145 miles) per hour, the storm was category 4 strength when the image was acquired, having undergone an eyewall replacement cycle that weakened it slightly.
“The satellite imagery of Polo is very impressive, with the storm’s large, clear eye and extensive outflow pattern,” said Kristen Corbosiero, an atmospheric scientist at the State University of New York at Albany, who is working on a NASA project that uses satellite data to study tropical cyclone ventilation. “Weak winds above the system and good outflow at the top of the system also contributed to Polo’s rapid intensification.”
As Polo developed, it moved over areas where sea surface temperatures were as high as 32 degrees Celsius (90 degrees Fahrenheit)—2 to 3 degrees warmer than usual for September 23. Surface waters across much of the region were above 27.8°C (82°F), the temperature generally required to sustain and intensify hurricanes.
The map above (right) is based on data from the Multiscale Ultrahigh Resolution Sea Surface Temperature (MUR SST) project at NASA’s Jet Propulsion Laboratory, which blends satellite measurements from NASA, NOAA, and international missions with observations from ships and buoys. Rather than absolute temperatures, the map shows anomalies—how much warmer or cooler the ocean surface was on September 23, 2026, than the project’s 2003-2014 average for that date.
While the map above conveys temperatures at the water surface, the presence of warm water deeper in the column has likely contributed to the storm’s staying power, Corbosiero added. Sometimes hurricanes churn up cooler water from deep in the column that can slow a storm’s intensification, but in this case the cool water wake behind the storm appears minimal, and measurements and models show high ocean heat content at considerable depths.
Both Partyka and Corbosiero cautioned against attributing Polo’s rapid intensification directly to El Niño’s unusually warm surface temperatures in the central and eastern Pacific Ocean. Several hurricanes in this region have undergone rapid intensification in the past during La Niñaand neutral conditions, Corbosiero noted, including Hurricane Otis in 2023 and Patricia in 2015, both category 5 storms.
However, the overall amount of tropical cyclone activity in the eastern Pacific does typically increase during El Niño due to changes in large-scale ocean and atmospheric circulation patterns, and that’s what has happened so far in 2026. As of September 24, the accumulated cyclone energy in the region was nearly twice the norm, according to data from Colorado State University.
Côte d’Ivoire signed the Artemis Accords on Thursday, becoming the 75th signatory and marking a major milestone for this growing coalition. With the signing ceremony in the nation’s largest city, Abidjan, Côte d’Ivoire joined other like-minded nations and committed to the peaceful, transparent, and responsible exploration of the Moon, Mars, and beyond.
“The United States and Côte d’Ivoire already cooperate on Earth,” said NASA’s Deputy Administrator Matt Anderson. “Today, we expand that partnership beyond it. Joining the Artemis Accords opens new opportunities for our scientists, engineers, and institutions to work together as humanity returns to the Moon and prepares for what comes next. We’ve aligned on the principles. The opportunities are in front of us. And now we can get to work.”
The nation’s Minister of Higher Education and Scientific Research Adama Diawara signed on behalf of the country in a ceremony held during Africa Space Expo ASPEX 2026. Chargé d’affaires Junaid Munir from the U.S. Department of State witnessed the ceremony.
“This is a great achievement, and important for Côte d’Ivoire’s ambitions and for the rest of the African Union members,” said Director General of the Space Agency of Côte d’Ivoire Tidiane Outtara.
Côte d’Ivoire has expanded its involvement in space science and technology through years of international cooperation. Since 2019, the National Office of Technical Development of Côte d’Ivoire and NASA have collaborated on Earth observation and geodesy, a field that measures Earth’s shape, gravity, and movement. Together, the partners have advanced global geodetic networks, improved space‑based measurement techniques, and increased understanding of how Earth’s systems interact.
The country later established the Space Agency of Côte d’Ivoire in 2025 to coordinate national efforts in Earth observation, space weather, astronomy, satellite navigation, and communications.
In 2020, NASA and the State Department joined with seven other founding nations to establish the Artemis Accords, responding to the growing interest in lunar activities by both governments and private companies. The Artemis Accords are the first set of practical principles aimed at enhancing transparency, safety, and coordination among nations as they explore the Moon, Mars, and beyond, committing nations to:
Explore peaceably and transparently
Render aid to those in need
Enable access to scientific data
Ensure activities do not interfere with those of others
Preserve historically significant sites and artifacts by developing best practices
By signing the Artemis Accords, nations open the door to opportunities for future lunar exploration with NASA, advancing humanity’s return to the Moon, and shaping the Golden Age of exploration and innovation.
NASA’s SpaceX Crew-14 crew members during preflight training at SpaceX’s facility in Hawthorne, California (from left, Roscosmos cosmonaut Arutyun Kiviryan, NASA astronaut Chris Birch, NASA astronaut Kayla Barron, and JAXA (Japan Aerospace Exploration Agency) astronaut Makoto Suwa).
Credit: SpaceX
Four crew members from three space agencies will launch to the International Space Station no earlier than spring 2027 for a long-duration science expedition as part of NASA’s SpaceX Crew-14 mission.
NASA astronauts Kayla Barron and Chris Birch will serve as spacecraft commander and pilot, with JAXA (Japan Aerospace Exploration Agency) astronaut Makoto Suwa, and Roscosmos cosmonaut Arutyun Kiviryan as mission specialists. After docking, Crew-14 will join the space station’s Expedition 75/76.
This mission is the 14th commercial crew rotation with SpaceX under NASA’s Low Earth Orbit Program. The crew will conduct scientific investigations and technology demonstrations to help prepare humans for future exploration missions to the Moon and Mars and to benefit people on Earth.
This will be Barron’s second flight to the space station. She was selected as a NASA astronaut in 2017. Barron earned a bachelor’s degree in systems engineering from the U.S. Naval Academy in Annapolis, Maryland and a master’s degree in nuclear engineering from the University of Cambridge in England. A commander in the U.S. Navy, Barron earned her submarine warfare officer qualification, deploying three times aboard the USS Maine. She first launched to the space station in 2021 aboard NASA’s SpaceX Crew-3 mission, spending a total of 177 days in space across space station Expeditions 66/67. She completed two spacewalks and served as lead robotics operator for another. Most recently, Barron supported the development of new technologies and operational concepts for NASA’s Artemis program.
Selected as a NASA astronaut in 2021, Birch graduated from the University of Arizona in Tucson with degrees in mathematics and biochemistry and molecular biophysics. She earned a doctorate in biological engineering from the Massachusetts Institute of Technology, and later taught bioengineering at the University of California, Riverside, and scientific writing and communication at the California Institute of Technology in Pasadena. Birch competed as a decorated track cyclist on the U.S. National Team and was named to the Olympic Long Team for the 2020 Tokyo Games. She has served as a capsule communicator, supporting crews aboard the space station and during the Artemis II mission. Birch was crew lead for Expedition 72, working with flight control teams to help manage daily operations, and served as a crew representative for NASA’s Orion Program, supporting Artemis II mission development and operations. This will be her first spaceflight.
The Crew-14 mission also is the first spaceflight assignment for Suwa. Before JAXA selected him as an astronaut candidate in 2023, Suwa spent nearly a decade with the World Bank Group. Previously, he served in Rwanda as a Japan Overseas Cooperation Volunteer before joining the United Nations World Meteorological Organization. Suwa holds a doctorate in geosciences from Princeton University and completed basic training to become certified as an astronaut in 2024.
This mission will be Kiviryan’s first trip to the space station. He graduated from Saint Petersburg Suvorov Military School in 2010 and later studied at the Baltic State Technical University. He graduated in 2015 as an engineer specializing in rocket science and completed training in the operation of computer-controlled machines. Kiviryan was selected for the Gagarin Research and Test Cosmonaut Training Center Cosmonaut Corps in 2021 and has served as a test cosmonaut since 2023.
For more than 25 years, people have lived and worked continuously aboard the International Space Station, advancing scientific knowledge and making research breakthroughs that aren’t possible on Earth. The space station helps NASA understand and overcome the challenges of human spaceflight, expand commercial opportunities in low Earth orbit, and build on the foundation for long-duration missions to the Moon, as part of the Artemis program, and to Mars.
Learn more about International Space Station research and operations at:
An Air Force Reservist helped lead a joint three-member U.S. military team to a third-place finish in the novice division at the 2026 International Confederation of Reserve Officers Military Competition in Bucharest, Romania.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
The Ghosts of Five Supernovas
Explanation: The ghosts of five supernovas haunt this extraordinary image. It was acquired at Oukaïmeden Observatory in Morocco with approximately 200 hours of observations and shows a large patch of the sky, equivalent to the area of one thousand full moons tiled together, in the constellation of Auriga (the Charioteer). From left to right, the five supernova remnants visible across the field are G181.1+9.5, G182.4+4.3, G179.0+2.6, G180.0−1.7 (Sh2-240, the Spaghetti Nebula), and G178.2−4.2. They are highlighted in the annotated image, together with open clusterM37 and the Tadpole Nebula. As each explosion expanded into space, it created a growing shell of shocked gas and delicate filamentary structures shown in red (hydrogen) and blue (oxygen), respectively. These ancient stellar explosions happened independently; they are at various distances up to about several thousands of light-years away from Earth and have estimated ages up to tens of thousands of years old. Early humans may have seen them as bright new stars, fading over weeks or months.
Cool, marine air rolling off the Pacific Ocean led to a picturesque layer of morning clouds over western Washington and Oregon in mid-September 2026. Low-lying stratus clouds and fog extended as far inland as the western foothills of the Cascade Range. Near the coast, taller portions of the Olympic Mountains in Washington and the Oregon Coast Range appeared island-like, protruding above the cloud layer.
The MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA’s Terra satellite shows the extent of the Pacific Northwest’s cloudy cloak on September 19, 2026, at about 10:45 a.m. Pacific Time (17:45 Universal Time). Abundant clouds also appear offshore over the Pacific, while smoke from wildland fires fills valleys in the North Cascades.
For several nights in a row, marine air flowed onshore, according to the National Weather Service, bringing with it low-level clouds known as marine stratus. These clouds form when moist air near the surface, trapped beneath a warmer air layer in a temperature inversion, cools enough for its water vapor to condense. The surge of cool, moist conditions was particularly strong early on September 19, producing cloudy conditions all the way up to the Cascade foothills. Some areas witnessed foggy conditions, where clouds extended down to the ground.
That same day, when NASA’s Aqua satellite passed over the area at about 4:15 p.m. Pacific Time (23:15 Universal Time), skies had cleared over much of the area. However, some marine clouds still clung to the Oregon coast, where temperatures stayed cooler than inland locations.
NASA Earth Observatory image by Michala Garrison, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Lindsey Doermann.
The Republic of Croatia became the 74th signatory to the Artemis Accords on Wednesday during a ceremony in the capital city of Zagreb with NASA and U.S. Department of State officials present.
“It is my privilege to welcome the Republic of Croatia as the latest signatory of the Artemis Accords,” said NASA Deputy Matt Anderson in pre-recorded remarks during the ceremony. “Joining the Artemis Accords opens another chapter. We’ve aligned on the principles. The opportunities to contribute are growing. And now we can look toward what the United States and Croatia can accomplish together beyond Earth. Humanity’s opportunities in space are endless, and we are proud to welcome Croatia to the Artemis Accords community.”
Croatia’s Minister of Science, Education, and Youth Radovan Fuchs signed on behalf of the country. U.S. Ambassador to Croatia Nicole McGraw and Gregory Mann, NASA Europe representative, attended event.
“Croatian scientists and companies are demonstrating growing interest in the space industry,” said Fuchs. “We have therefore decided to expand our international cooperation by joining the Artemis Accords. This international agreement has been recognized as a key opportunity for the robust development of Croatia’s scientific community, the introduction of new technologies, and the strengthening of the economy.”
Croatia marked a major milestone with the successful launch of its first satellite, CroCube, on Dec. 21, 2024. The satellite reached orbit aboard a SpaceX Falcon 9 rocket, highlighting Croatia’s growing technological capabilities and interest in space collaboration.
NASA and the State Department joined with seven other founding nations to establish the Artemis Accords in 2020, responding to the growing interest in lunar activities by both governments and private companies.
The Artemis Accords are the first set of practical principles aimed at enhancing transparency, safety, and coordination among like-minded nations as they explore the Moon, Mars, and beyond, committing nations to:
Explore peaceably and transparently
Render aid to those in need
Enable access to scientific data
Ensure activities do not interfere with those of others
Preserve historically significant sites and artifacts by developing best practices
By signing the Artemis Accords, nations open the door to opportunities for future lunar exploration with NASA, advancing humanity’s return to the Moon, and shaping the Golden Age of space exploration and innovation.
Dark blue water in Lake Powell fills several bays and branching canyons amid a light orange desert landscape. The Glen Canyon Dam and the town of Page, Arizona, are visible in the lower left.
NASA Earth Observatory / Lauren Dauphin
Water in Lake Powell is at record-low levels and looks like a wide river winding through a light orange desert landscape. The Glen Canyon Dam and the town of Page, Arizona, are visible in the lower left.
NASA Earth Observatory / Lauren Dauphin
Dark blue water in Lake Powell fills several bays and branching canyons amid a light orange desert landscape. The Glen Canyon Dam and the town of Page, Arizona, are visible in the lower left.
NASA Earth Observatory / Lauren Dauphin
Water in Lake Powell is at record-low levels and looks like a wide river winding through a light orange desert landscape. The Glen Canyon Dam and the town of Page, Arizona, are visible in the lower left.
NASA Earth Observatory / Lauren Dauphin
September 1, 2017
September 10, 2026
Lake Powell stood at one of its highest levels in the past decade on September 1, 2017 (left), and at a record low on September 10, 2026, in these images acquired with the OLI (Operational Land Imager) on Landsat 8. NASA Earth Observatory images by Lauren Dauphin.
The effects of a meager mountain snowpack across the Upper Colorado Basin in winter 2025-2026 had made their way downstream to Lake Powell by summer. After seasonal snowmelt declined to a relative trickle, the second-largest reservoir in the U.S. sat at record-low levels in late August and early September.
These images show a portion of Lake Powell just above Glen Canyon Dam as observed by the OLI (Operational Land Imager) on the NASA-USGS Landsat 8 satellite on September 1, 2017 (left), and September 10, 2026 (right). In the 2026 image, the water level stood at 3,517.24 feet. About a month prior, it had dipped below the previous record-low level of 3,519.92 feet, set on April 13, 2023, and continued to tick downward in early September. The 2017 image represents one of the highest water levels of the past decade.
The Colorado River feeds Lake Powell and then Lake Mead farther downstream, which also hit record-low levels in August 2026. Managed by the U.S. Bureau of Reclamation (USBR) and other agencies, the river provides water and electric power to more than 40 million people—including in Las Vegas, Phoenix, Los Angeles, and San Diego—and water to some 5 million acres of farmland in the Southwest.
Much of the Colorado Basin is arid or semi-arid, so a large portion of the river’s flow originates as snowmelt from higher elevations. The Upper Colorado Basin, like many mountainous areas across the U.S. West, saw unusually little snow accumulation in winter 2025-2026, constituting a snow drought. Stretches of record warmth further sapped the snowpack. As a result, water from snowmelt did little to replenish lake levels in spring, as it typically does.
The effect of the megadrought in the U.S. Southwest in the 21st century is reflected in Lake Powell’s water level, as measured by the U.S. Bureau of Reclamation. The lake first reached a record low on August 15, 2026, and continued declining through early September. It remained above the minimum power pool elevation of 3,490 feet, below which the dam’s hydroelectric turbines can no longer generate energy effectively.
NASA Earth Observatory/Lauren Dauphin
The USBR took steps in April 2026 to stabilize Lake Powell and keep it from falling below the level needed for hydropower production—an outcome the agency deemed possible by August 2026 without intervention. USBR began releasing water from Flaming Gorge Reservoir in northern Utah and southern Wyoming into Lake Powell. It also reduced releases from Lake Powell into Lake Mead, canceled a “controlled flood” in April intended to build sandbars for fish habitat, and skipped a “cool mix” release in August aimed at protecting native species.
Drought in the U.S. Southwest has been ongoing since about the start of the 21st century—what experts have called a megadrought—and continues to strain water resources. Several projects and tools funded by NASA and powered in part by NASA Earth observations are helping decision-makers throughout the Colorado Basin monitor drought and respond to its effects.
At the Colorado River headwaters, for example, a dashboard based on the Western Land Data Assimilation System (WLDAS) provides real-time soil moisture, snow water equivalent, and evapotranspiration visualizations that inform Colorado’s drought task force, as well as weekly U.S. Drought Monitor maps.
Nearer to Lake Powell, the Drought Severity Evaluation Tool, co-developed with the Navajo Nation, helps leaders monitor localized drought indices, precipitation trends, and vegetation health across tribal lands. (With funding from NOAA’s National Integrated Drought Information System, its adoption expanded to Oklahoma’s Chickasaw and Choctaw Nations in 2025.) And the Colorado River Integrated Assessment tool, developed by Arizona State University researchers in partnership with the Central Arizona Project, consolidates improved modeling and NASA-satellite-validated information on snowpack, surface and groundwater storage, soil moisture, and more across the entire basin into a single interactive view.
(April 30, 2026) — The SpaceX Crew-13 members are pictured in their pressure suits seated inside a mockup Dragon spacecraft during a preflight training session at the company’s headquarters in Hawthorne, California. From left are, Roscosmos Sergey Teteryatnikov, NASA astronauts Luke Delaney and Jessica Watkins, and CSA (Canadian Space Agency) astronaut Joshua Kutryk.
Credit: SpaceX
During NASA’s SpaceX Crew‑13 mission aboard the International Space Station, astronauts will support a series of biomedical and human performance investigations, including a new collaborative effort to study how spaceflight affects blood flow and clotting. NASA also is testing crew members’ manual piloting skills, evaluating methods to counter vision and brain changes, gathering essential health data to inform future missions, and measuring forces astronauts experience during return‑to‑Earth to help refine re-entry hardware and procedures.
Among upcoming research, a new collaboration with ESA (European Space Agency), called Venous Haemostasis, builds on previous studies of blood flow in space by combining the two space agencies’ research efforts. By coordinating blood collections and other physiological data, researchers can reduce how often astronauts need blood drawn while combining analytical measurements to better understand how microgravity affects blood clotting and circulation.
“In space, weightlessness can disrupt normal blood flow in astronauts’ veins,” said Jason Lytle, one of the study’s principal investigators and a cardiovascular researcher at NASA’s Johnson Space Center in Houston. “Irregular and slow blood flow can increase the risk of blood clot formation, a serious health condition. Venous Haemostasis will help us understand why these changes may occur in some astronauts but not others.”
Before, during, and after flight, astronauts will undergo MRI scans, jugular vein ultrasounds, blood pressure checks, and blood draws so researchers can track changes in blood flow and blood composition. Results will inform preventative measures for at-risk crew members and improve health and safety on future missions. Researchers also hope to learn whether knowledge gained from this and other studies may lead to better ways to prevent and treat blood clots both in space and on Earth.
A performance study, called Manual Piloting, uses lunar-landing simulations to test how well astronauts can handle challenging landings after spending extended time in microgravity. Because long-duration spaceflight can affect sensory systems, orientation, and motion control during shifts between gravity environments, researchers are evaluating how those changes influence piloting performance and whether refresher training shortly before landing can strengthen capabilities and decision-making.
Researchers also will continue the B-Complex study, which investigates if a daily B-vitamin supplement can reduce or prevent Spaceflight-Associated Neuro-ocular Syndrome (SANS), a condition that can change astronauts’ eye structure during long-duration missions. Past research suggests taking B vitamins daily during spaceflight may help protect astronauts from SANS. Participating crew members will undergo vision tests and take B vitamins before, during, and after flight to evaluate the supplement’s effectiveness. The study also will assess whether the B vitamins influence how crew members’ blood vessels function before and after flight.
Select Crew-13 astronauts also will participate in three additional Human Research Program studies: Standard Measures, Spacecraft Occupant Risk, and Zero T2. Standard Measures collects consistent physiological and behavioral data from as many crew members as possible to establish baselines for research aimed at countering adverse effects. Spacecraft Occupant Risk characterizes the forces astronauts experience during landing to help NASA refine strategies and hardware to reduce injury risks. Zero T2 tracks the exercise routines of select crew members to compare health and performance data between astronauts who use the treadmill for aerobic exercise aboard station and those who do not. The comparisons will help researchers build exercise plans for future Artemis and deep-space missions, where spacecraft size could limit or eliminate treadmill use.
“Together, these investigations will help NASA better understand how the human body responds to spaceflight and whether specific strategies can effectively protect astronaut health and performance,” said Michael Stenger, Human Research Program chief scientist at NASA Johnson. “Knowledge gained will pave the way for NASA’s efforts to safely send humans farther into the solar system, including Artemis missions to the Moon, work on the Moon Base, and future expeditions to Mars.”
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NASA’s Human Research Program pursues methods and technologies to support safe, productive human space travel. Through science conducted in laboratories, ground-based analogs, commercial missions, the International Space Station and Artemis missions, the program scrutinizes how spaceflight affects human bodies and behaviors. Such research drives the program’s quest to innovate ways that keep astronauts healthy and mission ready as human space exploration expands to the Moon, Mars, and beyond.
