Members Can Post Anonymously On This Site
What is a Black Hole? We Asked a NASA Expert: Episode 59
-
Similar Topics
-
By NASA
3 Min Read NASA Shares Final Contenders for Artemis II Moon Mascot Design Contest
NASA is down to 25 finalists for the Artemis II zero gravity indicator set to fly with the mission’s crew around the Moon and back next year.
Astronauts Reid Wiseman, Victor Glover, and Christina Koch of NASA, and CSA (Canadian Space Agency) astronaut Jeremy Hansen will soon select one of the finalist designs to join them inside the Orion spacecraft as their Moon mascot.
“The Artemis II zero gravity indicator will be special for the crew,” said Reid Wiseman, Artemis II commander. “In a spacecraft filled with complex hardware to keep the crew alive in deep space, the indicator is a friendly and useful way to highlight the human element that is so critical to our exploration of the universe. Our crew is excited about these designs from across the world and we are looking forward to bringing the winner along for the ride.”
A zero gravity indicator is a small plush item that typically rides with a crew to visually indicate when they are in space. For the first eight minutes after liftoff, the crew and their indicator nearby will still be pushed into their seats by gravity, and the force of the climb into space. When the main engines of the SLS (Space Launch System) rocket’s core stage cut off, gravity’s restraints are lifted, but the crew will still be strapped safely into their seats – their zero gravity indicator’s ability to float will provide proof that they’ve made it into space.
Artemis II will mark the first time that the public has had a hand in creating the crew’s mascot.
These designs – ideas spanning from Moon-related twists on Earthly creatures to creative visions of exploration and discovery – were selected from more than 2,600 submissions from over 50 countries, including from K-12 students. The finalists represent 10 countries including the United States, Canada, Colombia, Finland, France, Germany, Japan, Peru, Singapore, and Wales.
View the finalist designs:
Lucas Ye | Mountain View, California“Rise” Kenan Ziyan | Canyon, Texas“Zappy Zebra” Royal School, SKIES Space Club | Winnipeg, Manitoba, Canada“Luna the Space Polar Bear” Garden County Schools | Oshkosh, Nebraska“Team GarCo” Richellea Quinn Wijaya | Singapore“Parsec – The Bird That Flew to the Moon” Anzhelika Iudakova | Finland“Big Steps of Little Octopus” Congressional School | Falls Church, Virginia“Astra-Jelly” Congressional School | Falls Church, Virginia“Harper, Chloe, and Mateo’s ZGI” Alexa Pacholyk | Madison, Connecticut“Artemis” Leila Fleury | Rancho Palos Verdes, California“Beeatrice” Oakville Trafalgar School | Oakville, Ontario, Canada“Lepus the Moon Rabbit” Avon High School | Avon, Connecticut“Sal the Salmon” Daniela Colina | Lima, Peru“Corey the Explorer” Caroline Goyer-Desrosiers | St. Eustache, Quebec, Canada“Flying Squirrel Ready for Its Take Off to Space!” Giulia Bona | Berlin, Germany“Art & the Giant” Tabitha Ramsey | Frederick, Maryland“Lunar Crust-acean” Gabriela Hadas | Plano, Texas“Celestial Griffin” Savon Blanchard | Pearland, Texas“Soluna Flier” Ayako Moriyama | Kyoto, Japan“MORU: A Cloud Aglow with Moonlight and Hope” Johanna Beck | McPherson, Kansas“Creation Mythos” Guillaume Truong | Toulouse, France“Space Mola-mola (aka Moon Fish) Plushie” Arianna Robins | Rockledge, Florida“Terra the Titanosaurus” Sandy Moya | Madrid, Colombia“MISI: Guardian of the Journey” Bekah Crowmer | Mooresville, Indiana“Mona the Moon Moth” Courtney John | Llanelli, Wales“Past, Present, Future” In March, NASA announced it was seeking design ideas from global creators for a zero gravity indicator to fly aboard Artemis II, the first crewed mission under NASA’s Artemis campaign. Creators were asked to submit ideas representing the significance of Artemis, the mission, or exploration and discovery, and to meet specific size and materials requirements. Crowdsourcing company Freelancer facilitated the contest on NASA’s behalf though the NASA Tournament Lab, managed by the agency’s Space Technology Mission Directorate.
Once the crew has selected a final design, NASA’s Thermal Blanket Lab will fabricate it for flight. The indicator will be tethered inside Orion before launch.
The approximately 10-day mission is another step toward missions on the lunar surface and helping the agency prepare for future human missions to Mars.
Through Artemis, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars.
View the full article
-
By NASA
5 Min Read NASA, Army National Guard Partner on Flight Training for Moon Landing
By Corinne Beckinger
When Artemis astronauts land on the Moon’s South Pole in a commercial human landing system, they will encounter a landscape pockmarked with deep craters, sloped connecting ridges, and harsh lighting conditions. The Moon’s lack of contrast, combined with its rolling terrain, will also pose a challenge, making it difficult for astronauts to overcome visual illusions on the lunar surface.
NASA astronaut Bob Hines (left) and Colorado Army National Guard HAATS instructor Ethan Jacobs practice landing procedures in the Rocky Mountains of Colorado in April 2025. Depending on the season, the snowy or dusty conditions can cause visual obstruction. Lunar dust can cause similar visual impairment during future crewed missions. In the mountains of northern Colorado, NASA and the U.S. Army National Guard are using military helicopters to develop a foundational lunar landersimulated flight training course to help astronauts practice flight and landing procedures for the Moon.
For decades, military helicopter pilots have trained at the HAATS (High-Altitude Army National Guard Aviation Training Site) in Gypsum, Colorado. In 2021, NASA and the Colorado Army National Guard began working together to develop a course specifically for the next generation of lunar explorers.
That NASA-specific course is scheduled to be finalized in August 2025, marking an important milestone for Artemis crewed landings training efforts.
“NASA is using a three-pronged approach with motion-based simulation, in-flight lunar landing analog training, and in-flight lunar simulation to build out its foundational training for Artemis Moon landings,” said NASA astronaut Doug Wheelock, who helped coordinate the training program. “Helicopters at or above 10,000 feet are not really efficient in the thin air, forcing us into operating with very thin power margins similar to the Apollo astronauts having to manage energy and momentum to land safely. The operations along with the terrain at the HAATS course in Colorado’s Rocky Mountains provide a valuable, real-world opportunity for Artemis astronauts to practice flying and landing in conditions similar to maneuvering a lander in the lunar environment.”
NASA astronaut Raja Chari participates in the HAATS course in April 2025. Since 2021, 22 NASA astronauts and one ESA (European Space Agency) astronaut have participated and evaluated the course based on functionality and Artemis mission needs. NASA/Laura Kiker NASA astronaut Raja Chari participates in the HAATS course in April 2025. Since 2021, 22 NASA astronauts and one ESA (European Space Agency) astronaut have participated and evaluated the course based on functionality and Artemis mission needs. NASA/Corinne Beckinger NASA’s human landing systems that will safely transport astronauts to and from the Moon’s surface will be provided by SpaceX and Blue Origin.
NASA’s Artemis III mission will build on earlier test flights and add new capabilities, including SpaceX’s Starship Human Landing System and advanced spacesuits, to send the first astronauts to explore the lunar South Pole and prepare humanity to go to Mars.
While each industry provider is responsible for training Artemis astronauts on its specific lander, NASA is establishing foundational training to help prepare astronauts for crewed flights.
Flight training opportunities like this are vital to mission success and crew safety.”
Doug Wheelock
NASA Astronaut
“Over the last few years, NASA and the Army National Guard have worked closely to evaluate training procedures and landing zone areas, incorporating accounts from Apollo astronauts,” Wheelock said. “During training flights at HAATS, astronauts can experience the visual illusions, cross-cockpit communication, and degraded visibility they may experience navigating to their landing zone near the lunar south pole. Flight training opportunities like this are vital to mission success and crew safety.”
Paired with trained instructors from the Army National Guard, astronauts fly to mountaintops and valleys in a range of aircraft, including LUH-72 Lakotas, CH-47 Chinooks, and UH-60 Black Hawks.
While one astronaut pilots the aircraft, an astronaut in the back charts the landing area, marking key landmarks, identifying potential hazards, and helping to track the flight path. Throughout the week-long course, the landing zones and situations become more challenging, allowing astronauts to experience team dynamics and practice communication skills they will need to land on the Moon.
“Our full-time Colorado Army National Guard pilots have thousands of flight hours navigating the Rocky Mountains at altitudes ranging from 6,500 to 14,200 feet, and we are reaching new heights by providing realistic and relevant training with NASA for Artemis,” said first sergeant Joshua Smith of the HAATS program. “Our Colorado Army National Guard pilots may not fly around the Moon, but we wear our motto, de monitbus ad astra — from the mountains to the stars — with pride.”
Fast Facts
On the Moon’s South Pole, the Sun is never more than 1.5 degrees above or below the horizon. With the Sun at such a low angle and with only a thin exosphere, shadows are stark, and astronauts may find it difficult to determine distances and heights.
The Moon’s atmosphere is extremely thin, with few particles, and is called an exosphere. The Moon’s exosphere is thin enough to glow in sunlight, which has been observed by spacecraft and some of the Apollo astronauts. The Moon’s surface is challenging to land on. There are inactive volcanoes, bounders, large basins, craters, and cracks in the Moon’s crust, caused by the Earth’s gravity tugging on the Moon. Moon dust can also obscure the view from the windows of a commercial human landing system, and affect sensors that relay important information, such as altitude and velocity, to astronauts. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars – for the benefit of all.
For more information about Artemis visit:
https://www.nasa.gov/artemis
Share
Details
Last Updated Aug 18, 2025 EditorBeth RidgewayContactCorinne M. Beckingercorinne.m.beckinger@nasa.govLocationMarshall Space Flight Center Related Terms
Human Lander Challenge General Human Landing System Program Marshall Space Flight Center Explore More
3 min read Human Rating and NASA-STD-3001
Article 3 days ago 3 min read NASA Seeks Proposals for 2026 Human Exploration Rover Challenge
Article 3 days ago 4 min read NASA IXPE’s ‘Heartbeat Black Hole’ Measurements Challenge Current Theories
Article 6 days ago Keep Exploring Discover More Topics From NASA
Artemis
Human Landing System
Earth’s Moon
The Moon makes Earth more livable, sets the rhythm of ocean tides, and keeps a record of our solar system’s…
Artemis III
View the full article
-
By NASA
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA now is accepting proposals from student teams for a contest to design, build, and test rovers for Moon and Mars exploration through Sept. 15.
Known as the Human Exploration Rover Challenge, student rovers should be capable of traversing a course while completing mission tasks. The challenge handbook has guidelines for remote-controlled and human-powered divisions.
The cover of the HERC 2026 handbook, which is now available online. “Last year, we saw a lot of success with the debut of our remote-controlled division and the addition of middle school teams,” said Vemitra Alexander, the activity lead for the challenge at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “We’re looking forward to building on both our remote-controlled and human-powered divisions with new challenges for the students, including rover automation.”
This year’s mission mimics future Artemis missions to the lunar surface. Teams are challenged to test samples of soil, water, and air from sites along a half-mile course that includes a simulated field of asteroid debris, boulders, erosion ruts, crevasses, and an ancient streambed. Human-powered rover teams will play the role of two astronauts in a lunar terrain vehicle and must use a custom-built task tool to manually collect samples needed for testing. Remote-controlled rover teams will act as a pressurized rover, and the rover itself will contain the tools necessary to collect and test samples onboard.
“NASA’s Human Exploration Rover Challenge creates opportunities for students to develop the skills they need to be successful STEM professionals,” said Alexander. “This challenge will help students see themselves in the mission and give them the hands-on experience needed to advance technology and become the workforce of tomorrow.”
Seventy-five teams comprised of more than 500 students participated in the agency’s 31st rover challenge in 2025. Participants represented 35 colleges and universities, 38 high schools, and two middle schools, across 20 states, Puerto Rico, and 16 nations around the world.
The 32nd annual competition will culminate with an in-person event April 9-11, 2026, at the U.S. Space & Rocket Center near NASA Marshall.
The rover challenge is one of NASA’s Artemis Student Challenges, reflecting the goals of the Artemis campaign, which seeks to explore the Moon for scientific discovery, technology advancement, and to learn how to live and work on another world as we prepare for human missions to Mars. NASA uses such challenges to encourage students to pursue degrees and careers in the fields of science, technology, engineering, and mathematics.
Since its inception in 1994, more than 15,000 students have participated in the rover challenge – with many former students now working at NASA or within the aerospace industry.
To learn more about HERC, visit:
https://www.nasa.gov/roverchallenge/
Share
Details
Last Updated Aug 15, 2025 EditorBeth RidgewayLocationMarshall Space Flight Center Related Terms
Marshall Space Flight Center Explore More
4 min read NASA IXPE’s ‘Heartbeat Black Hole’ Measurements Challenge Current Theories
Article 3 days ago 6 min read NASA’s Hubble, Chandra Spot Rare Type of Black Hole Eating a Star
NASA’s Hubble Space Telescope and NASA’s Chandra X-ray Observatory have teamed up to identify a…
Article 3 weeks ago 4 min read Stay Cool: NASA Tests Innovative Technique for Super Cold Fuel Storage
Article 4 weeks ago Keep Exploring Discover Related Topics
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
By NASA
NASA Honor Award recipients are shown with their award plaques, alongside NASA Stennis Space Center Director John Bailey and Deputy Director Christine Powell, following the ceremony at NASA Stennis on Aug. 13. Pictured (left to right) is Andrew Bracey, Briou Bourgeois, Jared Grover, Robert Simmers, Robert Williams, Richard Wear, Tom Stanley, Alison Dardar, Marvin Horne, Cary Tolman, Tim Pierce, Rebecca Mataya, Bailey, Powell, Gina Ladner, and Brittany Bouche. NASA/Danny Nowlin NASA Stennis Space Center Director John Bailey speaks to employees during the NASA Honor Awards ceremony at NASA Stennis on Aug. 13. NASA/Danny Nowlin NASA Stennis Space Center Director John Bailey and Deputy Director Christine Powell presented NASA Honor Awards to employees during an onsite ceremony Aug. 13.
One NASA Stennis employee received NASA’s Outstanding Leadership Medal. The medal is awarded to government employees for notable leadership accomplishments that have significantly influenced the NASA mission.
Marvin Horne of Fulton, Maryland, received the NASA Outstanding Leadership Medal for his work in the Office of Procurement that has resulted in significant cost savings for the agency. Among his accomplishments, Horne designed, implemented, and led an integrated contract management office between NASA Stennis, NASA’s Michoud Assembly Facility in New Orleans, and NASA’s Marshall Space Flight Center in Huntsville, Alabama. The office transformed facility services from independent models to a shared model. The innovative solution was the first joint contract management office at NASA Stennis comprised of procurement, finance, and technical personnel designed to implement effective and efficient business processes. Horne currently serves as the NASA acting administrator for procurement.
Three NASA Stennis employees received NASA’s Exceptional Service Medal. The medal is awarded to government employees for sustained performance that embodies multiple contributions to NASA projects, programs, or initiatives.
Jared Grover of Diamondhead, Mississippi, received the NASA Exceptional Service Medal for his contributions to the success of the NASA Stennis E Test Complex through his dedication and technical expertise. As a NASA mechanical operations engineer, he has led various testing and facility preparation efforts, worked with challenging propellants, and trained new personnel. His work has supported numerous NASA and commercial aerospace projects Grover is also active in community outreach, promoting NASA’s mission and inspiring future engineers.
Tim Pierce of Long Beach, Mississippi, received the NASA Exceptional Service Medal following 26 years with NASA and 41 years working at NASA Stennis as a contractor and civil servant in the Center Operations Directorate. Through Pierce’s contributions, NASA Stennis became a leader in drafting agreements with external agencies, streamlining administrative procedures, and enhancing partnerships. In one notable instance, he led efforts to collaborate with county officials on a sewer treatment project that will save costs and optimize underused infrastructure. Pierce retired from NASA in January 2025.
Barry Robinson of Slidell, Louisiana, received the NASA Exceptional Service Medal in absentia for service to the nation’s space program and achievement across multiple propulsion test programs and projects. Robinson joined NASA in 1994 and worked on the space shuttle main engine test project, eventually becoming a test operations consultant. Over the years, Robinson held various roles, including chief of the NASA Stennis Mechanical Engineering Branch and project manager for projects supporting NASA’s SLS (Space Launch System) rocket for Artemis missions to the Moon and beyond. Robinson retired from NASA in December 2024.
One NASA Stennis employee received NASA’s Exceptional Engineering Achievement Medal. The medal is awarded to both government and non-government individuals for exceptional engineering contributions toward achievement of NASA’s mission.
Richard Wear of Slidell, Louisiana, received the NASA Exceptional Engineering Achievement Medal for his contributions to the NASA Stennis Engineering and Test Directorate. Wear serves as the subject matter expert in thermal and fluid systems analysis. In that role, he has greatly contributed to facilitating the use of liquid natural gas propellant in testing onsite, including by developing a Cryogenics in Propulsion Testing training course to support future test projects and programs. His contributions have significantly enhanced NASA’s support for commercial partners at NASA Stennis.
Eight NASA Stennis employees received NASA’s Exceptional Achievement Medal. This medal is awarded to any government employee for a significant specific achievement or substantial improvement in operations, efficiency, service, financial savings, science, or technology which contributes to the mission of NASA.
Leslie Anderson of Picayune, Mississippi, received the NASA Exceptional Achievement Medal in absentia for leadership and customer service as the lead accountant in the Office of the Chief Financial Officer at NASA Stennis. Anderson has successfully managed critical financial activities with technical expertise, project management, and strong customer service skills. Her efforts help maintain federal partnerships worth approximately $70 million annually and contribute to the success of NASA Stennis, demonstrating NASA’s core values of integrity, teamwork, excellence, and inclusion.
Alison Dardar of Diamondhead, Mississippi, received the NASA Exceptional Achievement Medal for innovation in improving financial and technical processes associated with the $1 billion-plus consolidated operations and maintenance contract for NASA Stennis and NASA’s Michoud Assembly Facility in New Orleans. As senior budget analyst in the NASA Stennis Office of the Chief Financial Officer, Dardar led in identifying and addressing key reporting and accounting issues related to the contract. Her innovations resulted in a 55% improvement in cost reporting accuracy and $20 million in savings to the contract.
Gina Ladner of Diamondhead, Mississippi, received the NASA Exceptional Achievement Medal for management, problem solving, and leadership during a year-long detail as chief of the NASA Stennis Facilities Services Division. During the year, Ladner led the division team through numerous changes and tackled unexpected challenges, including a severe weather event that featured confirmed tornados onsite and a contractor work stoppage activity, to ensure ongoing site operations. She also led in numerous infrastructure investments, including repairs to roadways, fire systems, and communications equipment.
Rebecca Mataya of Carriere, Mississippi, received the NASA Exceptional Achievement Medal for service as a budget analyst in the NASA Stennis Office of the Chief Financial Officer in improving processes and operations. As an analyst on the procurement development team for a new operations, services, and infrastructure contract, Mataya identified creative methods to increase cost savings and maximize facility projects. She also has helped secure over $408 million for facility improvements, enhancing water systems, power generation, and more.
Tom Stanley of Biloxi, Mississippi, received the NASA Exceptional Achievement Medal for contributions to improve NASA’s technology transfer process. As the NASA Stennis technology transfer officer, he developed a tool to standardize and automate evaluation of software usage agreements, reducing costs by 10 times and evaluation time by 75%. The changes led to record numbers of agreements awarded. Stanley also created a tool for contract closeouts, which has contributed to cost savings for the agency.
Cary Tolman of Fort Walton Beach, Florida, received the NASA Exceptional Achievement Medal for work in the NASA Office of the General Counsel. Beyond her role as procurement attorney, Tolman established a software and management audit review team to provide consistent and timely legal advice on software licenses and terms. Tolman’s work has helped NASA save $85 million and simplified legal support for software issues while reducing cybersecurity and financial risk.
Casey Wheeler of Gulfport, Mississippi, received the NASA Exceptional Achievement Medal for leadership and innovation in replacing the high pressure water industrial water system that supports crucial testing facilities at NASA Stennis. As project manager in the NASA Stennis Center Operations Directorate, Wheeler showcased his planning and coordination skills by completing the complex project without delaying rocket engine testing. His work restored the system to full design pressure in an area that directly supports NASA’s SLS (Space Launch System) rocket through RS-25 engine testing, and other critical projects.
Dale Woolridge of Slidell, Louisiana, received the NASA Exceptional Achievement Medal in absentia for contributions as project manager in the NASA Stennis Center Operations Directorate. Woolridge successfully led multiple construction projects, completing them on time and within budget. One notable project was the refurbishment of the miter gates at NASA Stennis’ navigational lock, which supports NASA’s rocket engine testing operations. The team completed the refurbishment ahead of schedule and within budget, ensuring minimal disruption to NASA operations.
Four NASA Stennis employees received NASA’s Early Career Achievement Medal. The medal is awarded to government employees for unusual and significant performance during the first 10 years of an individual’s career in support of the agency.
Briou Bourgeois of Pass Christian, Mississippi, received the NASA Early Career Achievement for his contributions in the NASA Stennis Engineering and Test Directorate. Bourgeois joined NASA in 2017 and has worked on various projects, including the SLS (Space Launch System) core stage Green Run test series and RS-25 engine testing for Artemis missions. Bourgeois played a key role in modifying the liquid oxygen tanking process during the SLS core stage series. He has since become test director in the NASA Stennis E Test Complex and a leader in commercial test projects at NASA Stennis.
Brandon Ladner of Poplarville, Mississippi, received the NASA Early Career Achievement Medal for contributions to the Exploration Upper Stage Test Project on the Thad Cochran Test Stand at NASA Stennis. As the NASA lead mechanical design engineer for the project, Ladner has significantly contributed to the design and build-up of the B-2 position of the Thad Cochran Test Stand in preparation for Green Run testing of the new SLS (Space Launch System) upper stage. He has led in completion of numerous large design packages and provided valuable engineering oversight to improve construction schedule.
Robert Simmers of Slidell, Louisiana, received the NASA Early Career Achievement for his expertise and versatility since joining NASA in 2015 as a member of the NASA Stennis Safety and Mission Assurance Directorate team. He serves as the safety point of contact for the Thad Cochran Test Stand (B-2). In that role, he supported all operations during Green Run testing of NASA’s SLS (Space Launch System) core stage. Simmers also has supported safety audits at various NASA centers. In 2020, he became the NASA Stennis explosive safety officer responsible for explosive safety and compliance.
Robert Williams of Gulfport, Mississippi, received the NASA Early Career Achievement for his work in the NASA Stennis Engineering and Test Directorate. Williams has worked with NASA for eight years, serving as a lead mechanical design engineer for several commercial test projects. Williams is recognized as a subject matter expert in structural systems and has contributed to various NASA Stennis projects, providing technical and modeling expertise.
Two NASA Stennis employees received NASA’s Silver Achievement Medal. The medal is awarded to any government or non-government employee for a stellar achievement that supports one or more of NASA’s core values, when it is deemed to be extraordinarily important and appropriate to recognize such achievement in a timely and personalized manner.
Brittany Bouche of Slidell, Louisiana, received the NASA Silver Achievement Medal for contributions in the NASA Stennis Center Operations Directorate. Bouche has held multiple key roles in the Facilities Services Division, including acting deputy, maintenance and operations lead, and project manager for several construction projects. She has successfully led various design and construction projects, completing them on time and within budget. These include a $9.1 million sewage system and treatment repair project, successfully completed with minimal service impact.
Andrew Bracey of Picayune, Mississippi, received the NASA Silver Achievement Medal for contributions as a NASA electrical design engineer at NASA Stennis. He has provided critical design support for work related to Green Run testing of the new SLS (Space Launch System) exploration upper stage. Bracey also has been crucial to the NASA Stennis vision of supporting commercial aerospace testing, leading preliminary design reviews for multiple projects onsite.
Read More on Stennis Space Center Share
Details
Last Updated Aug 14, 2025 EditorNASA Stennis CommunicationsContactC. Lacy Thompsoncalvin.l.thompson@nasa.gov / (228) 688-3333LocationStennis Space Center Related Terms
Stennis Space Center Explore More
6 min read A Defining Era: NASA Stennis and Space Shuttle Main Engine Testing
Article 3 months ago 4 min read NASA Stennis Releases First Open-Source Software
Article 3 months ago 5 min read NASA Stennis Software is Built for Future Growth
Article 3 months ago View the full article
-
By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Written by Michael Allen
An international team of astronomers using NASA’s IXPE (Imaging X-ray Polarimetry Explorer), has challenged our understanding of what happens to matter in the direct vicinity of a black hole.
With IXPE, astronomers can study incoming X-rays and measure the polarization, a property of light that describes the direction of its electric field.
The polarization degree is a measurement of how aligned those vibrations are to each other. Scientists can use a black hole’s polarization degree to determine the location of the corona – a region of extremely hot, magnetized plasma that surrounds a black hole – and how it generates X-rays.
This illustration of material swirling around a black hole highlights a particular feature, called the “corona,” that shines brightly in X-ray light. In this depiction, the corona can be seen as a purple haze floating above the underlying accretion disk, and extending slightly inside of its inner edge. The material within the inner accretion disk is incredibly hot and would glow with a blinding blue-white light, but here has been reduced in brightness to make the corona stand out with better contrast. Its purple color is purely illustrative, standing in for the X-ray glow that would not be obvious in visible light. The warp in the disk is a realistic representation of how the black hole’s immense gravity acts like an optical lens, distorting our view of the flat disk that encircles it. NASA/Caltech-IPAC/Robert Hurt In April, astronomers used IXPE to measure a 9.1% polarization degree for black hole IGR J17091-3624, much higher than they expected based on theoretical models.
“The black hole IGR J17091-3624 is an extraordinary source which dims and brightens with the likeness of a heartbeat, and NASA’s IXPE allowed us to measure this unique source in a brand-new way.” said Melissa Ewing, the lead of the study based at Newcastle University in Newcastle upon Tyne, England.
In X-ray binary systems, an extremely dense object, like a black hole, pulls matter from a nearby source, most often a neighboring star. This matter can begin to swirl around, flattening into a rotating structure known as an accretion disc.
The corona, which lies in the inner region of this accretion disc, can reach extreme temperatures up to 1.8 billion degrees Fahrenheit and radiate very luminous X-rays. These ultra-hot coronas are responsible for some of the brightest X-ray sources in the sky.
Despite how bright the corona is in IGRJ17091-364, at some 28,000 light-years from Earth, it remains far too small and distant for astronomers to capture an image of it.
“Typically, a high polarization degree corresponds with a very edge-on view of the corona. The corona would have to be perfectly shaped and viewed at just the right angle to achieve such a measurement,” said Giorgio Matt, professor at the University of Roma Tre in Italy and a co-author on this paper. “The dimming pattern has yet to be explained by scientists and could hold the keys to understanding this category of black holes.”
The stellar companion of this black hole isn’t bright enough for astronomers to directly estimate the system’s viewing angle, but the unusual changes in brightness observed by IXPE suggest that the edge of the accretion disk was directly facing Earth.
The researchers explored different avenues to explain the high polarization degree.
In one model, astronomers included a “wind” of matter lifted from the accretion disc and launched away from the system, a rarely seen phenomenon. If X-rays from the corona were to meet this matter on their way to IXPE, Compton scattering would occur, leading to these measurements.
Fast Facts
Polarization measurements from IXPE carry information about the orientation and alignment of emitted X-ray light waves. The high the degree of polarization, the more the X-ray waves are traveling in sync. Most polarization in the corona come from a process known as Compton scattering, where light from the accretion disc bounces off the hot plasma of the corona, gaining energy and aligning to vibrate in the same direction. “These winds are one of the most critical missing pieces to understand the growth of all types of black holes,” said Maxime Parra, who led the observation and works on this topic at Ehime University in Matsuyama, Japan. “Astronomers could expect future observations to yield even more surprising polarization degree measurements.”
Another model assumed the plasma in the corona could exhibit a very fast outflow. If the plasma were to be streaming outwards at speeds as high as 20% the speed of light, or roughly 124 million miles per hour, relativistic effects could boost the observed polarization.
In both cases, the simulations could recreate the observed polarization without a very specific edge-on view. Researchers will continue to model and test their predictions to better understand the high polarization degree for future research efforts.
More about IXPE
IXPE, which continues to provide unprecedented data enabling groundbreaking discoveries about celestial objects across the universe, is a joint NASA and Italian Space Agency mission with partners and science collaborators in 12 countries. IXPE is led by NASA’s Marshall Space Flight Center in Huntsville, Alabama. BAE Systems, Inc., headquartered in Falls Church, Virginia, manages spacecraft operations together with the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder.
Learn more about IXPE’s ongoing mission here:
https://www.nasa.gov/ixpe
Share
Details
Last Updated Aug 12, 2025 EditorBeth RidgewayContactCorinne Edmistoncorinne.m.edmiston@nasa.govLocationMarshall Space Flight Center Related Terms
IXPE (Imaging X-ray Polarimetry Explorer) Marshall Astrophysics Marshall Science Research & Projects Marshall Space Flight Center Explore More
6 min read NASA’s Hubble, Chandra Spot Rare Type of Black Hole Eating a Star
NASA’s Hubble Space Telescope and NASA’s Chandra X-ray Observatory have teamed up to identify a…
Article 3 weeks ago 4 min read Stay Cool: NASA Tests Innovative Technique for Super Cold Fuel Storage
Article 4 weeks ago 4 min read NASA’s IXPE Imager Reveals Mysteries of Rare Pulsar
Article 4 weeks ago Keep Exploring Discover Related Topics
Chandra
Space Telescope
IXPE News
Black Holes
Black Holes Black holes are among the most mysterious cosmic objects, much studied but not fully understood. These objects aren’t…
Imaging X-ray Polarimetry Explorer (IXPE)
The Imaging X-ray Polarimetry Explorer (IXPE) is a space observatory built to discover the secrets of some of the most…
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.