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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
The blazar BL Lacertae, a supermassive black hole surrounded by a bright disk and jets oriented toward Earth, provided scientists with a unique opportunity to answer a longstanding question: How are X-rays generated in extreme environments like this?
NASA’s IXPE (Imaging X-ray Polarimetry Explorer) collaborated with radio and optical telescopes to find answers. The results (preprint available here), to be published in the journal Astrophysical Journal Letters, show that interactions between fast-moving electrons and particles of light, called photons, must lead to this X-ray emission.
This artist’s concept depicts the central region of the blazar BL Lacertae, a supermassive black hole surrounded by a bright disk and a jet oriented toward Earth. The galaxy’s central black hole is surrounded by swirls of orange in various shades representing the accretion disk of material falling toward the black hole. While black holes are known for pulling in material, this accretion process can result in the ejection of jets of electrons at nearly the speed of light. The jet of matter is represented by the cone of light that starts at the center of the black hole and widens out as it reaches the bottom of the image. It is streaked with lines of white, pink and purple which represent helix-shaped magnetic fields. We can observe these jets in many wavelengths of light including radio, optical, and X-ray. NASA’s Imaging X-ray Polarimetry Explorer (IXPE) recently collaborated with radio and optical telescopes to observe this jet and determine how the X-rays are generated in these types of celestial environments.NASA/Pablo Garcia Scientists had two competing possible explanations for the X-rays, one involving protons and one involving electrons. Each of these mechanisms would have a different signature in the polarization of X-ray light. Polarization is a property of light that describes the average direction of the electromagnetic waves that make up light.
If the X-rays in a black hole’s jets are highly polarized, that would mean that the X-rays are produced by protons gyrating in the magnetic field of the jet or protons interacting with jet’s photons. If the X-rays have a lower polarization degree, it would suggest that electron-photons interactions lead to X-ray production.
IXPE, which launched Dec. 9, 2021, is the only satellite flying today that can make such a polarization measurement.
“This was one of the biggest mysteries about supermassive black hole jets” said Iván Agudo, lead author of the study and astronomer at the Instituto de Astrofísica de Andalucía – CSIC in Spain. “And IXPE, with the help of a number of supporting ground-based telescopes, finally provided us with the tools to solve it.”
Astronomers found that electrons must be the culprits through a process called Compton Scattering. Compton scattering (or the Compton effect) happens when a photon loses or gains energy after interacting with a charged particle, usually an electron. Within jets from supermassive black holes, electrons move near the speed of light. IXPE helped scientists learn that, in the case of a blazar jet, the electrons have enough energy to scatter photons of infrared light up to X-ray wavelengths.
BL Lacertae (BL Lac for short) is one of the first blazars ever discovered, originally thought to be a variable star in the Lacerta constellation. IXPE observed BL Lac at the end of November 2023 for seven days along with several ground-based telescopes measuring optical and radio polarization at the same time. While IXPE observed BL Lac in the past, this observation was special. Coincidentally, during the X-ray polarization observations, the optical polarization of BL Lac reached a high number: 47.5%.
“This was not only the most polarized BL Lac has been in the past 30 years, this is the most polarized any blazar has ever been observed!” said Ioannis Liodakis, one of the primary authors of the study and astrophysicist at the Institute of Astrophysics – FORTH in Greece.
IXPE found the X-rays were far less polarized than the optical light. The team was not able to measure a strong polarization signal and determined that the X-rays cannot be more polarized than 7.6%. This proved that electrons interacting with photons, via the Compton effect, must explain the X-rays.
The fact that optical polarization was so much higher than in the X-rays can only be explained by Compton scattering.
Steven Ehlert
Project Scientist for IXPE at Marshall Space Flight Center
“The fact that optical polarization was so much higher than in the X-rays can only be explained by Compton scattering”, said Steven Ehlert, project scientist for IXPE and astronomer at the Marshall Space Flight Center.
“IXPE has managed to solve another black hole mystery” said Enrico Costa, astrophysicist in Rome at the Istituto di Astrofísica e Planetologia Spaziali of the Istituto Nazionale di Astrofísica. Costa is one of the scientists who conceived this experiment and proposed it to NASA 10 years ago, under the leadership of Martin Weisskopf, IXPE’s first principal investigator. “IXPE’s polarized X-ray vision has solved several long lasting mysteries, and this is one of the most important. In some other cases, IXPE results have challenged consolidated opinions and opened new enigmas, but this is how science works and, for sure, IXPE is doing very good science.”
What’s next for the blazar research?
“One thing we’ll want to do is try to find as many of these as possible,” Ehlert said. “Blazars change quite a bit with time and are full of surprises.”
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
Elizabeth Landau
NASA Headquarters
elizabeth.r.landau@nasa.gov
202-358-0845
Lane Figueroa
Marshall Space Flight Center, Huntsville, Ala.
lane.e.figueroa@nasa.gov
256.544.0034
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Last Updated May 06, 2025 EditorBeth RidgewayContactElizabeth R. Landauelizabeth.r.landau@nasa.govLocationMarshall Space Flight Center Related Terms
Marshall Space Flight Center IXPE (Imaging X-ray Polarimetry Explorer) Marshall Astrophysics Explore More
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Black Holes
Black Holes Black holes are among the most mysterious cosmic objects, much studied but not fully understood. These objects aren’t…
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By USH
Several days ago, a massive blackout swept across large parts of Spain, Portugal, and parts of southern France. Millions were left without power as the interconnected European energy grid experienced a rare and abrupt failure. While authorities quickly pointed to a "rare atmospheric phenomenon" as the cause, not everyone is convinced.
Here are some explanations of authorities as well as controversial theories:
According to REN, Portugal’s national electricity grid operator, the blackout was triggered by a fault originating in Spain’s power infrastructure. The disruption, they claim, was linked to "induced atmospheric variation", a term referring to extreme temperature differences that led to anomalous oscillations in high-voltage transmission lines. These oscillations reportedly caused synchronization failures between regional grid systems, ultimately sparking a chain reaction of failures across the European network.
What makes the situation even more intriguing is that just days before the blackout, Spain hit a historic energy milestone. On April 16, for the first time, the country’s electricity demand was met entirely by renewable energy sources - solar, wind, and hydro, during a weekday. It raises questions whether the outage was caused by a technical failure of this new renewable energy system.
While this achievement is noteworthy, it also exposes the fragility of a grid increasingly reliant on variable energy sources, especially solar, which can fluctuate dramatically with weather and atmospheric conditions.
Despite official explanations, some experts and observers remain skeptical. There were no solar flares or geomagnetic storms in the days leading up to the blackout, and solar activity had been relatively calm. Critics argue that while atmospheric disturbances may have played a role, they are not sufficient to explain such a widespread, synchronized failure.
Despite the fact that the blackout this time was probably not caused by solar flares or geomagnetic storms it has been proven that Earth’s magnetic shield is rapidly weakening, leaving us increasingly vulnerable to powerful solar storms. The magnetic north pole is accelerating toward Siberia, and the South Atlantic Anomaly continues to expand, ominous signs that a looming plasma event could bring consequences far beyond just technological disruption.
This has led to speculation that the blackout could have been intentional, possibly even a test run for handling future crises or threats to infrastructure.
Among the more controversial theories is the suggestion that this event might have involved the use of a graphite bomb, a non-lethal weapon designed to disable power grids. These devices disperse ultra-fine carbon filaments into high-voltage power lines, causing short circuits by creating conductive paths between lines. Such an attack would appear as a grid malfunction but could be devastating in scale.
Another controversial theory is that the outage has been caused by weather manipulation systems such as HAARP or the Ice Cube Neutrino observatory, constructed at the Amundsen–Scott South Pole Station in Antarctica.
Could this have been a covert drill or a demonstration of vulnerability? Some point to global forums, such as the World Government Summit, where figures like Klaus Schwab have warned about Black Swan: An unpredictable event that is beyond what is normally expected of a situation and has potentially severe consequences.
Whether the blackout was triggered by a rare natural event, a technical failure, or something more deliberate, it seems only a matter of time before we face a true Black Swan event. View the full article
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By European Space Agency
The European Space Agency's XMM-Newton is playing a crucial role in investigating the longest and most energetic bursts of X-rays seen from a newly awakened black hole. Watching this strange behaviour unfold in real time offers a unique opportunity to learn more about these powerful events and the mysterious behaviour of massive black holes.
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By NASA
Tall plumes of white vapor rise from the rocky Venusian surface in this April 19, 1977, artist’s concept.NASA/Rick Guidice Tall plumes of white vapor rise from the rocky Venusian surface in this April 19, 1977, artist’s concept. A little over a year later, NASA’s Pioneer Venus 1 would launch as the first of a two-spacecraft orbiter-probe combination designed to study the atmosphere of Venus.
The first American spacecraft to orbit Venus, Pioneer Venus 1 used radar to map the surface of Venus. The probe found Venus to be generally smoother than Earth, though with a mountain higher than Mt. Everest and a chasm deeper than the Grand Canyon.
Thanks to exploration by Pioneer Venus 1 and other spacecraft like Magellan, Galileo, Cassini, and even the Parker Solar Probe, we now have a much better view of what the surface of Venus looks like.
Image credit: NASA/Rick Guidice
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By NASA
u0022The really interesting thing to me is how time theoretically acts strangely around black holes. According to Albert Einstein’s theory of gravity, black holes change the flow of time,u0022 said Jeremy Schnittman, Goddard research astrophysicist. u0022So much of how we experience the world is based on time, time marching steadily forward. Anything that changes that is a fascinating take on reality.u0022u003cstrongu003eu003cemu003eCredits: NASA’s Goddard Space Flight Center / Rebecca Rothu003c/emu003eu003c/strongu003e Name: Jeremy Schnittman
Formal Job Classification: Research astrophysicist
Organization: Gravitational Astrophysics Laboratory, Astrophysics Division (Code 663)
What do you do and what is most interesting about your role here at Goddard? How do you help support Goddard’s mission?
I try to understand the formation and properties of black holes. I also help develop ideas for new missions to study black holes.
What drew you to astrophysics?
I always liked science and math. The great thing about astrophysics is that it involves a little bit of everything – math, computer programming, physics, chemistry and even philosophy to understand the big picture, the enormity of space.
I have a B.A. in physics from Harvard, and a Ph.D. in physics from MIT. I came to Goddard in 2010 after two post-doctoral fellowships.
Explore how the extreme gravity of two orbiting supermassive black holes distorts our view. In this visualization, disks of bright, hot, churning gas encircle both black holes, shown in red and blue to better track the light source. The red disk orbits the larger black hole, which weighs 200 million times the mass of our Sun, while its smaller blue companion weighs half as much. Zooming into each black hole reveals multiple, increasingly warped images of its partner. Watch to learn more.
Credits: NASA’s Goddard Space Flight Center/Jeremy Schnittman and Brian P. Powell
Download high-resolution video and images from NASA’s Scientific Visualization Studio As an astrophysicist, what do you think about?
I think of myself as a computational physicist as opposed to an experimental or observational physicist. I write many computer programs to do computer simulations of black holes. I also do a lot of theoretical physics, which is pencil and paper work. I think a lot about equations and math to understand black holes.
What is most philosophical about black holes to me is not so much what people most often think about, that their gravity is so strong that even light cannot escape. The really interesting thing to me is how time theoretically acts strangely around black holes. According to Albert Einstein’s theory of gravity, black holes change the flow of time. If you could get close enough to a black hole, theoretically you could go back and forth in time. All our experiments and observations seem to indicate that is how black holes might behave.
So much of how we experience the world is based on time, time marching steadily forward. Anything that changes that is a fascinating take on reality.
Related Link: Gravity Assist: Black Hole Mysteries, with Jeremy Schnittman What do you tell the people you mentor?
I mentor undergraduate, graduate, and post graduate students in astrophysics. Since we are working remotely, I have students from all over the country. I help them with their research projects which mostly relate to black holes in some way. I also offer career advice and help them with their work-life balance. When possible, family comes first.
There are more people coming out of graduate school in astrophysics than there are jobs, so there are going to be many people who will not work for NASA or as a professor. Fortunately, there are a lot of other fascinating, related jobs, and I help guide the students there.
What do you do for fun?
I have a woodshop in our basement where I build furniture, dollhouses, toys, and other items for gifts. As a theoretical physicist, I don’t get to work in a lab. So it is nice to have some hands on experience.
I do a lot of hiking and cycling to exercise. I also enjoy spending time with my family.
Who is your favorite author?
Andy Weir is probably my favorite sci-fi author. I also love the epic naval historical fiction by Patrick O’Brian.
Who inspires you?
My childhood hero, who is still my scientific hero, is Albert Einstein. The more I work in astrophysics, the more he impresses me. Every single one of his predictions that we have been able to test has proven true. It may be a while, but someday I hope we prove his theories about time travel.
Also, I admire Kip Thorne, an American physicist from Cal Tech and recent Nobel laureate, who is “the man” when it comes to black holes. He is also a really nice, good guy, a real mensch. Very humble and down-to-earth. He is always extremely patient, kind and encouraging especially to the younger scientists. He is a good role model as I transition from junior to more senior status.
What is your one big dream?
I make a lot of predictions, so it would be exciting if one of my theories was proven correct. Hopefully someday.
By Elizabeth M. Jarrell
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Conversations with Goddard Conversations With Goddard is a collection of question and answer profiles highlighting the breadth and depth of NASA’s Goddard Space Flight Center’s talented and diverse workforce. The Conversations have been published twice a month on average since May 2011. Read past editions on Goddard’s “Our People” webpage.
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Last Updated Feb 10, 2025 Related Terms
Goddard Space Flight Center Astrophysics Galaxies, Stars, & Black Holes Research People of Goddard Explore More
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