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Urine tests detect high-risk HPV as effectively as DIY vaginal swabs
Urine tests detect high-risk HPV as effectively as DIY vaginal swabs
The foundations of eczema may start to be laid down in the womb
The foundations of eczema may start to be laid down in the womb
NASA’s Chandra Reveals Star’s Inner Conflict Before Explosion
The inside of a star turned on itself before it spectacularly exploded, according to a new study from NASA’s Chandra X-ray Observatory. Today, this shattered star, known as the Cassiopeia A supernova remnant, is one of the best-known, well-studied objects in the sky.
Over three hundred years ago, however, it was a giant star on the brink of self-destruction. The new Chandra study reveals that just hours before it exploded, the star’s interior violently rearranged itself. This last-minute shuffling of its stellar belly has profound implications for understanding how massive stars explode and how their remains behave afterwards.
Cassiopeia A (Cas A for short) was one of the first objects the telescope looked at after its launch in 1999, and astronomers have repeatedly returned to observe it.
“It seems like each time we closely look at Chandra data of Cas A, we learn something new and exciting,” said Toshiki Sato of Meiji University in Japan who led the study. “Now we’ve taken that invaluable X-ray data, combined it with powerful computer models, and found something extraordinary.”
As massive stars age, increasingly heavy elements form in their interiors by nuclear reactions, creating onion-like layers of different elements. Their outer layer is mostly made of hydrogen, followed by layers of helium, carbon and progressively heavier elements – extending all the way down to the center of the star.
Once iron starts forming in the core of the star, the game changes. As soon as the iron core grows beyond a certain mass (about 1.4 times the mass of the Sun), it can no longer support its own weight and collapses. The outer part of the star falls onto the collapsing core, and rebounds as a core-collapse supernova.
The new research with Chandra data reveals a change that happened deep within the star at the very last moments of its life. After more than a million years, Cas A underwent major changes in its final hours before exploding.
“Our research shows that just before the star in Cas A collapsed, part of an inner layer with large amounts of silicon traveled outwards and broke into a neighboring layer with lots of neon,” said co-author Kai Matsunaga of Kyoto University in Japan. “This is a violent event where the barrier between these two layers disappears.”
This upheaval not only caused material rich in silicon to travel outwards; it also forced material rich in neon to travel inwards. The team found clear traces of these outward silicon flows and inward neon flows in the remains of Cas A’s supernova remnant. Small regions rich in silicon but poor in neon are located near regions rich in neon and poor in silicon.
The survival of these regions not only provides critical evidence for the star’s upheaval, but also shows that complete mixing of the silicon and neon with other elements did not occur immediately before or after the explosion. This lack of mixing is predicted by detailed computer models of massive stars near the ends of their lives.
There are several significant implications for this inner turmoil inside of the doomed star. First, it may directly explain the lopsided rather than symmetrical shape of the Cas A remnant in three dimensions. Second, a lopsided explosion and debris field may have given a powerful kick to the remaining core of the star, now a neutron star, explaining the high observed speed of this object.
Finally, the strong turbulent flows created by the star’s internal changes may have promoted the development of the supernova blast wave, facilitating the star’s explosion.
“Perhaps the most important effect of this change in the star’s structure is that it may have helped trigger the explosion itself,” said co-author Hiroyuki Uchida, also of Kyoto University. “Such final internal activity of a star may change its fate—whether it will shine as a supernova or not.”
These results have been published in the latest issue of The Astrophysical Journal and are available online.
To learn more about Chandra, visit:
https://science.nasa.gov/chandra
Read more from NASA’s Chandra X-ray ObservatoryLearn more about the Chandra X-ray Observatory and its mission here:
Visual DescriptionThis release features a composite image of Cassiopeia A, a donut-shaped supernova remnant located about 11,000 light-years from Earth. Included in the image is an inset closeup, which highlights a region with relative abundances of silicon and neon.
Over three hundred years ago, Cassiopeia A, or Cas A, was a star on the brink of self-destruction. In composition it resembled an onion with layers rich in different elements such as hydrogen, helium, carbon, silicon, sulfur, calcium, and neon, wrapped around an iron core. When that iron core grew beyond a certain mass, the star could no longer support its own weight. The outer layers fell into the collapsing core, then rebounded as a supernova. This explosion created the donut-like shape shown in the composite image. The shape is somewhat irregular, with the thinner quadrant of the donut to the upper left of the off-center hole.
In the body of the donut, the remains of the star’s elements create a mottled cloud of colors, marbled with red and blue veins. Here, sulfur is represented by yellow, calcium by green, and iron by purple. The red veins are silicon, and the blue veins, which also line the outer edge of the donut-shape, are the highest energy X-rays detected by Chandra and show the explosion’s blast wave.
The inset uses a different color code and highlights a colorful, mottled region at the thinner, upper left quadrant of Cas A. Here, rich pockets of silicon and neon are identified in the red and blue veins, respectively. New evidence from Chandra indicates that in the hours before the star’s collapse, part of a silicon-rich layer traveled outwards, and broke into a neighboring neon-rich layer. This violent breakdown of layers created strong turbulent flows and may have promoted the development of the supernova’s blast wave, facilitating the star’s explosion. Additionally, upheaval in the interior of the star may have produced a lopsided explosion, resulting in the irregular shape, with an off-center hole (and a thinner bite of donut!) at our upper left.
News Media ContactMegan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu
Corinne Beckinger
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
corinne.m.beckinger@nasa.gov
NASA’s Chandra Reveals Star’s Inner Conflict Before Explosion
The inside of a star turned on itself before it spectacularly exploded, according to a new study from NASA’s Chandra X-ray Observatory. Today, this shattered star, known as the Cassiopeia A supernova remnant, is one of the best-known, well-studied objects in the sky.
Over three hundred years ago, however, it was a giant star on the brink of self-destruction. The new Chandra study reveals that just hours before it exploded, the star’s interior violently rearranged itself. This last-minute shuffling of its stellar belly has profound implications for understanding how massive stars explode and how their remains behave afterwards.
Cassiopeia A (Cas A for short) was one of the first objects the telescope looked at after its launch in 1999, and astronomers have repeatedly returned to observe it.
“It seems like each time we closely look at Chandra data of Cas A, we learn something new and exciting,” said Toshiki Sato of Meiji University in Japan who led the study. “Now we’ve taken that invaluable X-ray data, combined it with powerful computer models, and found something extraordinary.”
As massive stars age, increasingly heavy elements form in their interiors by nuclear reactions, creating onion-like layers of different elements. Their outer layer is mostly made of hydrogen, followed by layers of helium, carbon and progressively heavier elements – extending all the way down to the center of the star.
Once iron starts forming in the core of the star, the game changes. As soon as the iron core grows beyond a certain mass (about 1.4 times the mass of the Sun), it can no longer support its own weight and collapses. The outer part of the star falls onto the collapsing core, and rebounds as a core-collapse supernova.
The new research with Chandra data reveals a change that happened deep within the star at the very last moments of its life. After more than a million years, Cas A underwent major changes in its final hours before exploding.
“Our research shows that just before the star in Cas A collapsed, part of an inner layer with large amounts of silicon traveled outwards and broke into a neighboring layer with lots of neon,” said co-author Kai Matsunaga of Kyoto University in Japan. “This is a violent event where the barrier between these two layers disappears.”
This upheaval not only caused material rich in silicon to travel outwards; it also forced material rich in neon to travel inwards. The team found clear traces of these outward silicon flows and inward neon flows in the remains of Cas A’s supernova remnant. Small regions rich in silicon but poor in neon are located near regions rich in neon and poor in silicon.
The survival of these regions not only provides critical evidence for the star’s upheaval, but also shows that complete mixing of the silicon and neon with other elements did not occur immediately before or after the explosion. This lack of mixing is predicted by detailed computer models of massive stars near the ends of their lives.
There are several significant implications for this inner turmoil inside of the doomed star. First, it may directly explain the lopsided rather than symmetrical shape of the Cas A remnant in three dimensions. Second, a lopsided explosion and debris field may have given a powerful kick to the remaining core of the star, now a neutron star, explaining the high observed speed of this object.
Finally, the strong turbulent flows created by the star’s internal changes may have promoted the development of the supernova blast wave, facilitating the star’s explosion.
“Perhaps the most important effect of this change in the star’s structure is that it may have helped trigger the explosion itself,” said co-author Hiroyuki Uchida, also of Kyoto University. “Such final internal activity of a star may change its fate—whether it will shine as a supernova or not.”
These results have been published in the latest issue of The Astrophysical Journal and are available online.
To learn more about Chandra, visit:
https://science.nasa.gov/chandra
Read more from NASA’s Chandra X-ray ObservatoryLearn more about the Chandra X-ray Observatory and its mission here:
Visual DescriptionThis release features a composite image of Cassiopeia A, a donut-shaped supernova remnant located about 11,000 light-years from Earth. Included in the image is an inset closeup, which highlights a region with relative abundances of silicon and neon.
Over three hundred years ago, Cassiopeia A, or Cas A, was a star on the brink of self-destruction. In composition it resembled an onion with layers rich in different elements such as hydrogen, helium, carbon, silicon, sulfur, calcium, and neon, wrapped around an iron core. When that iron core grew beyond a certain mass, the star could no longer support its own weight. The outer layers fell into the collapsing core, then rebounded as a supernova. This explosion created the donut-like shape shown in the composite image. The shape is somewhat irregular, with the thinner quadrant of the donut to the upper left of the off-center hole.
In the body of the donut, the remains of the star’s elements create a mottled cloud of colors, marbled with red and blue veins. Here, sulfur is represented by yellow, calcium by green, and iron by purple. The red veins are silicon, and the blue veins, which also line the outer edge of the donut-shape, are the highest energy X-rays detected by Chandra and show the explosion’s blast wave.
The inset uses a different color code and highlights a colorful, mottled region at the thinner, upper left quadrant of Cas A. Here, rich pockets of silicon and neon are identified in the red and blue veins, respectively. New evidence from Chandra indicates that in the hours before the star’s collapse, part of a silicon-rich layer traveled outwards, and broke into a neighboring neon-rich layer. This violent breakdown of layers created strong turbulent flows and may have promoted the development of the supernova’s blast wave, facilitating the star’s explosion. Additionally, upheaval in the interior of the star may have produced a lopsided explosion, resulting in the irregular shape, with an off-center hole (and a thinner bite of donut!) at our upper left.
News Media ContactMegan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu
Corinne Beckinger
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
corinne.m.beckinger@nasa.gov
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Katie Bisci: Resourcing for Big Science
How are you helping set the stage for the Roman mission?
I’m a deputy project manager for resources on the Nancy Grace Roman Space Telescope team, sharing the role with Kris Steeley. Together, we oversee the business team, finance, outreach, scheduling, and more. I focus more on the “down and in” of the day-to-day team — helping the financial team, resource utilization across the project, and support service contracts management — while Kris handles more of the “up and out” external work with center management and NASA Headquarters. Kris and I collaborate on many things as well. The two of us have been together on Roman for many years, and we have definitely become one brain in many aspects of the role. The main goal in the job is programmatics: We need to understand and help along the technical parts of the mission, while also supporting cost and schedule control since Roman is a cost-capped mission. I try to make sure that I partner with our engineers to understand the technical part of Roman as much as possible. I find that I can’t do my job well on the programmatic side without working together closely with our engineers to understand the hardware and testing.
What drew you to NASA? Did you always intend to work here?
I think I always knew I wanted to go into the business and finance side of things, but I thought I’d end up at a big investment bank. I interned at one during college, but it just didn’t feel right for me. After graduating, I worked on corporate events for defense contractors in New York City. Then my husband got a job in Annapolis, Maryland, and I took a leap and applied for a resource analyst job at NASA, where some college friends were working. Looking back, as an oldest daughter it probably should have been obvious that project management would be a good fit! Once I got to NASA, I was really drawn in by the missions and work we do. It was so different from the corporate world. Being able to work on some of the coolest missions with some of the most brilliant minds out there is a gift. Almost 15 years later, I’m still here.
How did your career grow from there?
After serving as a resource analyst in the Safety and Mission Assurance Directorate at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, I moved into the center’s Astrophysics Projects Division, where I began working on Roman in 2012, back when it was just a small study called WFIRST (Wide Field Infrared Survey Telescope). I could never have imagined at the time what that small study would turn into. People at NASA often say they “grew up” on the James Webb Space Telescope, and for me I definitely “grew up” on Roman. I became the mission business manager, then financial manager, and now a deputy project manager for resources. I feel lucky that most of my career has been spent on Roman. Adding it up, I’ve been on this project for over a decade. I’ve worked with so many amazing people, not just at NASA Goddard, but across the United States. It’s hard to believe we are so close to launching.
What’s been the highlight of your career so far?
Becoming part of the management team on Roman, for sure. Working with the leadership team has been incredible. The best part about Roman is the people. It still cracks me up to look at the plethora of people we have in the same room for our weekly senior staff meeting, from the programmatic and finance types like myself, to engineers leading super complicated integration and test programs, Ph.D.s, and some of the most brilliant science minds I will probably ever know. The Roman team is amazing, and those relationships are what keep me excited to come to work every day.
Has your work influenced your understanding or appreciation of astronomy?
Absolutely. I’ve learned so much just by being around brilliant people like our project scientist Julie McEnery. I even recently gave a talk about Roman at my daughter’s school! Being able to stand up in front of a group of children and talk about what Roman science is going to do is something I never would have been able to do prior to working here. I’ve learned about how the Hubble Space Telescope, Webb, and Roman all build on each other during my time on this project. And it’s really incredible science. I’ve also developed a deep admiration for the engineers who have built Roman. As a business focused person, our engineering team has really helped me understand the different facets of what our engineering team does on Roman. They are so patient with me! It’s really fulfilling to be a small part of something so big.
What advice do you have for others who are interested in doing similar work?
If you’re in finance, don’t just learn the numbers — learn the work behind them. Understand the mission, the tech, the people. That’s what helps you move from analyst to leader. People can tell when you really get what they’re doing, and that’s how you become a better partner and manager.
What’s life like outside NASA?
I have three kids — ages 9, 5, and 3 — so life is busy! When I’m not working, I’m usually at their sports games or chauffeuring them around to one event or another. It’s a little bit of a rat race, but this season of life is also really fun. Recently, my family and I have gotten back into traveling now that my kids are a little bit older. We took a spring break trip to Europe, which was fantastic. Spending time with my family and friends is everything. Whether it’s going to the beach, spending time at the pool, or hanging out on the sideline of a lacrosse game, just like at work it’s being with my people that I thrive on. And maybe one day I will have time for more hobbies again!
By Ashley Balzer
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Where no gourd has gone before | Space photo of the day for Aug. 28, 2025
Katie Bisci: Resourcing for Big Science
How are you helping set the stage for the Roman mission?
I’m a deputy project manager for resources on the Nancy Grace Roman Space Telescope team, sharing the role with Kris Steeley. Together, we oversee the business team, finance, outreach, scheduling, and more. I focus more on the “down and in” of the day-to-day team — helping the financial team, resource utilization across the project, and support service contracts management — while Kris handles more of the “up and out” external work with center management and NASA Headquarters. Kris and I collaborate on many things as well. The two of us have been together on Roman for many years, and we have definitely become one brain in many aspects of the role. The main goal in the job is programmatics: We need to understand and help along the technical parts of the mission, while also supporting cost and schedule control since Roman is a cost-capped mission. I try to make sure that I partner with our engineers to understand the technical part of Roman as much as possible. I find that I can’t do my job well on the programmatic side without working together closely with our engineers to understand the hardware and testing.
What drew you to NASA? Did you always intend to work here?
I think I always knew I wanted to go into the business and finance side of things, but I thought I’d end up at a big investment bank. I interned at one during college, but it just didn’t feel right for me. After graduating, I worked on corporate events for defense contractors in New York City. Then my husband got a job in Annapolis, Maryland, and I took a leap and applied for a resource analyst job at NASA, where some college friends were working. Looking back, as an oldest daughter it probably should have been obvious that project management would be a good fit! Once I got to NASA, I was really drawn in by the missions and work we do. It was so different from the corporate world. Being able to work on some of the coolest missions with some of the most brilliant minds out there is a gift. Almost 15 years later, I’m still here.
How did your career grow from there?
After serving as a resource analyst in the Safety and Mission Assurance Directorate at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, I moved into the center’s Astrophysics Projects Division, where I began working on Roman in 2012, back when it was just a small study called WFIRST (Wide Field Infrared Survey Telescope). I could never have imagined at the time what that small study would turn into. People at NASA often say they “grew up” on the James Webb Space Telescope, and for me I definitely “grew up” on Roman. I became the mission business manager, then financial manager, and now a deputy project manager for resources. I feel lucky that most of my career has been spent on Roman. Adding it up, I’ve been on this project for over a decade. I’ve worked with so many amazing people, not just at NASA Goddard, but across the United States. It’s hard to believe we are so close to launching.
What’s been the highlight of your career so far?
Becoming part of the management team on Roman, for sure. Working with the leadership team has been incredible. The best part about Roman is the people. It still cracks me up to look at the plethora of people we have in the same room for our weekly senior staff meeting, from the programmatic and finance types like myself, to engineers leading super complicated integration and test programs, Ph.D.s, and some of the most brilliant science minds I will probably ever know. The Roman team is amazing, and those relationships are what keep me excited to come to work every day.
Has your work influenced your understanding or appreciation of astronomy?
Absolutely. I’ve learned so much just by being around brilliant people like our project scientist Julie McEnery. I even recently gave a talk about Roman at my daughter’s school! Being able to stand up in front of a group of children and talk about what Roman science is going to do is something I never would have been able to do prior to working here. I’ve learned about how the Hubble Space Telescope, Webb, and Roman all build on each other during my time on this project. And it’s really incredible science. I’ve also developed a deep admiration for the engineers who have built Roman. As a business focused person, our engineering team has really helped me understand the different facets of what our engineering team does on Roman. They are so patient with me! It’s really fulfilling to be a small part of something so big.
What advice do you have for others who are interested in doing similar work?
If you’re in finance, don’t just learn the numbers — learn the work behind them. Understand the mission, the tech, the people. That’s what helps you move from analyst to leader. People can tell when you really get what they’re doing, and that’s how you become a better partner and manager.
What’s life like outside NASA?
I have three kids — ages 9, 5, and 3 — so life is busy! When I’m not working, I’m usually at their sports games or chauffeuring them around to one event or another. It’s a little bit of a rat race, but this season of life is also really fun. Recently, my family and I have gotten back into traveling now that my kids are a little bit older. We took a spring break trip to Europe, which was fantastic. Spending time with my family and friends is everything. Whether it’s going to the beach, spending time at the pool, or hanging out on the sideline of a lacrosse game, just like at work it’s being with my people that I thrive on. And maybe one day I will have time for more hobbies again!
By Ashley Balzer
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Izaña-2 joins the laser game to track space debris
In Tenerife, Spain, stands a unique duo: ESA’s Izaña-1 and Izaña-2 laser-ranging stations. Together, they form an optical technology testbed of the European Space Agency that takes the monitoring of space debris and satellites to a new level while maturing new technologies for commercialisation.
Space debris is a threat to satellites and is rapidly becoming a daily concern for satellite operators. The Space Safety Programme, part of ESA Operations, managed from ESOC in Germany, helps develop new technologies to detect and track debris, and to prevent collisions in orbit in new and innovative ways.
One of these efforts takes place at the Izaña station in Tenerife. There, ESA and partner companies are testing how to deliver precise orbit data on demand with laser-based technologies. The Izaña-2 station was recently finalised by the German company DiGOS and is now in use.
To perform space debris laser ranging, Izaña-2 operates as a laser transmitter, emitting high-power laser pulses towards objects in space. Izaña-1 then acts as the receiver of the few photons that are reflected back. The precision of the laser technology enables highly accurate data for precise orbit determination, which in turn is crucial for actionable collision avoidance systems and sustainable space traffic management.
With the OMLET (Orbital Maintenance via Laser momEntum Transfer) project, ESA combines different development streams and possibilities for automation to support European industry with getting two innovative services market-ready: on-demand ephemeris provision and laser-based collision avoidance services for end users such as satellite operators.
A future goal is to achieve collision avoidance by laser momentum transfer, where instead of the operational satellite, the piece of debris will be moved out of the way. This involves altering the orbit of a piece of space debris slightly by applying a small force to the object through laser illumination.
The European Space Agency actively supports European industry in capitalising on the business opportunities that not only safeguard our satellites but also pave the way for the sustainable use of space.