"When beggars die, there are no comets seen;
The heavens themselves blaze forth the death of princes."

— William Shakespeare
Julius Cæsar

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Don't miss the stars of the 'Summer Triangle' twinkle with the Milky Way after sunset

Space.com - Thu, 08/28/2025 - 2:00pm
Altair, Vega and Deneb can be seen shining with the Milky Way throughout August.
Categories: Astronomy

NASA, International Astronauts to Address Students from New York

NASA News - Thu, 08/28/2025 - 1:56pm
From left to right: JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui, and NASA astronauts Jonny Kim (seated), Zena Cardman, and Mike Fincke conduct training scenarios with their instructors at NASA’s Johnson Space Center in Houston, for their upcoming mission to the International Space Station. Credit: NASA/Helen Arase Vargas

NASA astronaut Jonny Kim and JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui will connect with students in New York as they answer prerecorded science, technology, engineering, and mathematics (STEM) questions aboard the International Space Station.

The Earth-to-space call will begin at 9:20 a.m. EDT on Friday, Sept. 5, and will stream live on the agency’s Learn With NASA YouTube channel.

Media interested in covering the event must RSVP by 5 p.m. Wednesday, Sept. 3, to Sara Sloves at: 917-441-1234 or ssloves@thecomputerschool.org.

The Computer School will host this event in New York for middle school students. The goal of this event is to extend learning by exposing students to the real-world experiences and engineering challenges of astronauts working and living aboard the International Space Station.

For nearly 25 years, astronauts have continuously lived and worked aboard the space station, testing technologies, performing science, and developing skills needed to explore farther from Earth. Astronauts communicate with NASA’s Mission Control Center in Houston 24 hours a day through SCaN’s (Space Communications and Navigation) Near Space Network.

Research and technology investigations taking place aboard the space station benefit people on Earth and lay the groundwork for other agency deep space missions. As part of NASA’s Artemis campaign, the agency will send astronauts to the Moon to prepare for future human exploration of Mars, inspiring the world through discovery in a new Golden Age of innovation and exploration.

See more information on NASA in-flight calls at:

https://www.nasa.gov/stemonstation

-end-

Gerelle Dodson
Headquarters, Washington
202-358-1600
gerelle.q.dodson@nasa.gov

Sandra Jones
Johnson Space Center, Houston
281-483-5111
sandra.p.jones@nasa.gov

Share Details Last Updated Aug 28, 2025 LocationNASA Headquarters Related Terms
Categories: NASA

NASA, International Astronauts to Address Students from New York

NASA - Breaking News - Thu, 08/28/2025 - 1:56pm
From left to right: JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui, and NASA astronauts Jonny Kim (seated), Zena Cardman, and Mike Fincke conduct training scenarios with their instructors at NASA’s Johnson Space Center in Houston, for their upcoming mission to the International Space Station. Credit: NASA/Helen Arase Vargas

NASA astronaut Jonny Kim and JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui will connect with students in New York as they answer prerecorded science, technology, engineering, and mathematics (STEM) questions aboard the International Space Station.

The Earth-to-space call will begin at 9:20 a.m. EDT on Friday, Sept. 5, and will stream live on the agency’s Learn With NASA YouTube channel.

Media interested in covering the event must RSVP by 5 p.m. Wednesday, Sept. 3, to Sara Sloves at: 917-441-1234 or ssloves@thecomputerschool.org.

The Computer School will host this event in New York for middle school students. The goal of this event is to extend learning by exposing students to the real-world experiences and engineering challenges of astronauts working and living aboard the International Space Station.

For nearly 25 years, astronauts have continuously lived and worked aboard the space station, testing technologies, performing science, and developing skills needed to explore farther from Earth. Astronauts communicate with NASA’s Mission Control Center in Houston 24 hours a day through SCaN’s (Space Communications and Navigation) Near Space Network.

Research and technology investigations taking place aboard the space station benefit people on Earth and lay the groundwork for other agency deep space missions. As part of NASA’s Artemis campaign, the agency will send astronauts to the Moon to prepare for future human exploration of Mars, inspiring the world through discovery in a new Golden Age of innovation and exploration.

See more information on NASA in-flight calls at:

https://www.nasa.gov/stemonstation

-end-

Gerelle Dodson
Headquarters, Washington
202-358-1600
gerelle.q.dodson@nasa.gov

Sandra Jones
Johnson Space Center, Houston
281-483-5111
sandra.p.jones@nasa.gov

Share Details Last Updated Aug 28, 2025 LocationNASA Headquarters Related Terms
Categories: NASA

NASA Scientists Help Maryland County Plan to Beat Summer Heat Risks

NASA News - Thu, 08/28/2025 - 1:31pm

4 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater) These maps of Prince George’s County, MD, show surface temperatures collected a few hours apart on July 30, 2023 from the Landsat 9 satellite and the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) instrument. The dark blue spots in the right hand image are likely clouds that formed in the afternoon.Credit: Stephanie Schollaert Uz, NASA Goddard Space Flight Center

Thousands of Americans are impacted each summer by excessive heat and humidity, some suffering from heat-related illnesses when the body can’t cool itself down. Data from NASA satellites could help local governments reduce the sweltering risks, thanks to a collaboration between NASA scientists and officials in Prince George’s County, Maryland. The effort demonstrates how local officials in other communities could turn to NASA data to inform decisions that provide residents with relief from summer heat.

NASA researchers and their Prince George’s County collaborators reported in Frontiers in Environmental Science that they used the Landsat 8 satellite, jointly operated by NASA and the US Geological Survey, and NASA’s Aqua satellite, to gain insight into surface temperature trends across the county over the past few decades. The data also show how temperatures have responded to changing land use and construction. It is information that county planners and environmental experts hope can aid them in their attempts to remediate and prevent heat dangers in the future. The collaboration may also help the county’s first responders anticipate and prepare for heat-related emergencies and injuries.

Cooperation with Prince George’s County expands on NASA’s historic role, said Stephanie Schollaert Uz, an applications scientist with NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and one of the study authors. “Applying government satellite data to county-level problems is new here. We’re trying to make it easier for people outside of NASA to use our data, in part by including how-to guides referenced at the end of our paper,” Schollaert Uz said.

In the long run, county officials hope to use NASA satellites to track the negative health impacts that arise from land use and modification. Removal of tree cover and the construction of non-permeable roads, parking lots, and structures that lead to water runoff are among the factors that create heat islands, where temperatures in localized areas soar relative to the surrounding landscape. In addition to the direct dangers of heat for county residents and workers, areas with higher-than-normal temperatures can drive intense local weather events.

“There’s potentially a greater incidence of microbursts,” said Mary Abe of Prince George’s County’s sustainability division. “The atmosphere can become supercharged over hot spots,” causing high winds and flood-inducing rains.

Prince George’s County planners anticipate relying on NASA satellites to determine where residents and county employees are at greater risk, predict how future construction could impact heat dangers, and develop strategies to moderate heat in areas currently experiencing elevated summer temperatures. Efforts might include protecting existing trees and planting new ones. It could include replacing impermeable surfaces (cement, pavement, etc.) with alternatives that let water soak into the ground rather than running off into storm drains. To verify and calibrate the satellite observations crucial for such planning, county experts are considering enlisting residents to act as citizen scientists to collect temperature and weather data on the ground, Abe said.

Eventually, the NASA satellite temperature data could also lead to strategies to curb insect-borne diseases, said Evelyn Hoban, associate director for the Prince George’s County division of environmental health and communicable disease. “Once we know where the higher temperatures are, we can check to see if they create mosquito or tick breeding grounds,” said Hoban, who coauthored the study. “We could then focus our outreach and education, and perhaps prevention efforts, on areas of greater heat and risk.”

A NASA guide is available to aid other communities who hope to duplicate the Prince George’s County study. The guide provides introductions on a variety of NASA satellite and ground-based weather station data. Instructions for downloading and analyzing the data are illustrated in an accompanying tutorial that uses the Prince George’s County study as an example for other communities to follow on their own.

One of the greatest benefits of the collaboration, Abe said, is the boost in credibility that comes from incorporating NASA resources and expertise in the county’s efforts to improve safety and health. “It’s partly the NASA brand. People recognize it and they’re really intrigued by it,” she said. “Working with NASA builds confidence that the decision-making process is based firmly in science.”

By James Riordon
NASA Goddard Space Flight Center

Media contact: Elizabeth Vlock
NASA Headquarters

Share Details Last Updated Aug 28, 2025 EditorJames RiordonLocationNASA Goddard Space Flight Center Related Terms Explore More 3 min read NASA’s ECOSTRESS Detects ‘Heat Islands’ in Extreme Indian Heat Wave Article 3 years ago 6 min read Landsat Legacy: NASA-USGS Program Observing Earth from Space Turns 50 Article 3 years ago 2 min read NASA’s ECOSTRESS Sees Las Vegas Streets Turn Up the Heat Article 3 years ago Keep Exploring Discover More Topics From NASA

Missions

Humans in Space

Climate Change

Solar System

Categories: NASA

NASA Scientists Help Maryland County Plan to Beat Summer Heat Risks

NASA - Breaking News - Thu, 08/28/2025 - 1:31pm

4 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater) These maps of Prince George’s County, MD, show surface temperatures collected a few hours apart on July 30, 2023 from the Landsat 9 satellite and the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) instrument. The dark blue spots in the right hand image are likely clouds that formed in the afternoon.Credit: Stephanie Schollaert Uz, NASA Goddard Space Flight Center

Thousands of Americans are impacted each summer by excessive heat and humidity, some suffering from heat-related illnesses when the body can’t cool itself down. Data from NASA satellites could help local governments reduce the sweltering risks, thanks to a collaboration between NASA scientists and officials in Prince George’s County, Maryland. The effort demonstrates how local officials in other communities could turn to NASA data to inform decisions that provide residents with relief from summer heat.

NASA researchers and their Prince George’s County collaborators reported in Frontiers in Environmental Science that they used the Landsat 8 satellite, jointly operated by NASA and the US Geological Survey, and NASA’s Aqua satellite, to gain insight into surface temperature trends across the county over the past few decades. The data also show how temperatures have responded to changing land use and construction. It is information that county planners and environmental experts hope can aid them in their attempts to remediate and prevent heat dangers in the future. The collaboration may also help the county’s first responders anticipate and prepare for heat-related emergencies and injuries.

Cooperation with Prince George’s County expands on NASA’s historic role, said Stephanie Schollaert Uz, an applications scientist with NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and one of the study authors. “Applying government satellite data to county-level problems is new here. We’re trying to make it easier for people outside of NASA to use our data, in part by including how-to guides referenced at the end of our paper,” Schollaert Uz said.

In the long run, county officials hope to use NASA satellites to track the negative health impacts that arise from land use and modification. Removal of tree cover and the construction of non-permeable roads, parking lots, and structures that lead to water runoff are among the factors that create heat islands, where temperatures in localized areas soar relative to the surrounding landscape. In addition to the direct dangers of heat for county residents and workers, areas with higher-than-normal temperatures can drive intense local weather events.

“There’s potentially a greater incidence of microbursts,” said Mary Abe of Prince George’s County’s sustainability division. “The atmosphere can become supercharged over hot spots,” causing high winds and flood-inducing rains.

Prince George’s County planners anticipate relying on NASA satellites to determine where residents and county employees are at greater risk, predict how future construction could impact heat dangers, and develop strategies to moderate heat in areas currently experiencing elevated summer temperatures. Efforts might include protecting existing trees and planting new ones. It could include replacing impermeable surfaces (cement, pavement, etc.) with alternatives that let water soak into the ground rather than running off into storm drains. To verify and calibrate the satellite observations crucial for such planning, county experts are considering enlisting residents to act as citizen scientists to collect temperature and weather data on the ground, Abe said.

Eventually, the NASA satellite temperature data could also lead to strategies to curb insect-borne diseases, said Evelyn Hoban, associate director for the Prince George’s County division of environmental health and communicable disease. “Once we know where the higher temperatures are, we can check to see if they create mosquito or tick breeding grounds,” said Hoban, who coauthored the study. “We could then focus our outreach and education, and perhaps prevention efforts, on areas of greater heat and risk.”

A NASA guide is available to aid other communities who hope to duplicate the Prince George’s County study. The guide provides introductions on a variety of NASA satellite and ground-based weather station data. Instructions for downloading and analyzing the data are illustrated in an accompanying tutorial that uses the Prince George’s County study as an example for other communities to follow on their own.

One of the greatest benefits of the collaboration, Abe said, is the boost in credibility that comes from incorporating NASA resources and expertise in the county’s efforts to improve safety and health. “It’s partly the NASA brand. People recognize it and they’re really intrigued by it,” she said. “Working with NASA builds confidence that the decision-making process is based firmly in science.”

By James Riordon
NASA Goddard Space Flight Center

Media contact: Elizabeth Vlock
NASA Headquarters

Share Details Last Updated Aug 28, 2025 EditorJames RiordonLocationNASA Goddard Space Flight Center Related Terms Explore More 3 min read NASA’s ECOSTRESS Detects ‘Heat Islands’ in Extreme Indian Heat Wave Article 3 years ago 6 min read Landsat Legacy: NASA-USGS Program Observing Earth from Space Turns 50 Article 3 years ago 2 min read NASA’s ECOSTRESS Sees Las Vegas Streets Turn Up the Heat Article 3 years ago Keep Exploring Discover More Topics From NASA

Missions

Humans in Space

Climate Change

Solar System

Categories: NASA

Perseverance Mars rover stumbles upon wind-carved 'megaripples' on the Red Planet

Space.com - Thu, 08/28/2025 - 1:14pm
NASA's Perseverance rover captured a striking new image of massive, wind-carved sand formations known as "megaripples" during its latest exploration stop on the Red Planet.
Categories: Astronomy

Urine tests detect high-risk HPV as effectively as DIY vaginal swabs

New Scientist Space - Cosmology - Thu, 08/28/2025 - 1:00pm
Several countries now offer at-home vaginal swabs to detect HPV status in place of traditional cervical cancer screening, but urine tests seem to work just as well
Categories: Astronomy

Urine tests detect high-risk HPV as effectively as DIY vaginal swabs

New Scientist Space - Space Headlines - Thu, 08/28/2025 - 1:00pm
Several countries now offer at-home vaginal swabs to detect HPV status in place of traditional cervical cancer screening, but urine tests seem to work just as well
Categories: Astronomy

Deep-Sea Worm Produces Orpiment, a Toxic Yellow Pigment Used in Historical Art

Scientific American.com - Thu, 08/28/2025 - 1:00pm

A deep-sea worm that lives in hydrothermal vents is the first known animal to create orpiment, a toxic, arsenic-containing mineral that was used by artists for centuries

Categories: Astronomy

The foundations of eczema may start to be laid down in the womb

New Scientist Space - Cosmology - Thu, 08/28/2025 - 12:30pm
Eczema can be very distressing for children – and now it seems that its roots may at least partly lie in their mothers experiencing high levels of stress during pregnancy
Categories: Astronomy

The foundations of eczema may start to be laid down in the womb

New Scientist Space - Space Headlines - Thu, 08/28/2025 - 12:30pm
Eczema can be very distressing for children – and now it seems that its roots may at least partly lie in their mothers experiencing high levels of stress during pregnancy
Categories: Astronomy

NASA’s Chandra Reveals Star’s Inner Conflict Before Explosion

NASA News - Thu, 08/28/2025 - 12:17pm
This graphic features data from NASA’s Chandra X-ray Observatory of the Cassiopeia A (Cas A) supernova remnant that reveals that the star’s interior violently rearranged itself mere hours before it exploded. The main panel of this graphic is Chandra data that shows the location of different elements in the remains of the explosion: silicon (represented in red), sulfur (yellow), calcium (green) and iron (purple). The blue color reveals the highest-energy X-ray emission detected by Chandra in Cas A and an expanding blast wave. The inset reveals regions with wide ranges of relative abundances of silicon and neon. This data, plus computer modeling, reveal new insight into how massive stars like Cas A end their lives.X-ray: NASA/CXC/Meiji Univ./T. Sato et al.; Image Processing: NASA/CXC/SAO/N. Wolk

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 Observatory

Learn more about the Chandra X-ray Observatory and its mission here:

https://www.nasa.gov/chandra

https://chandra.si.edu

Visual Description

This 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 Contact

Megan 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

Share Details Last Updated Aug 28, 2025 EditorLee MohonContactCorinne M. Beckingercorinne.m.beckinger@nasa.govLocationMarshall Space Flight Center Related Terms Explore More 2 min read Hubble Homes in on Galaxy’s Star Formation

This NASA/ESA Hubble Space Telescope image features a galaxy whose asymmetric appearance may be the…

Article 9 hours ago
4 min read NASA Scientists Help Maryland County Plan to Beat Summer Heat Risks Article 1 day ago 6 min read Meet NASA’s Artemis II Moon Mission Masterminds Article 2 days ago
Categories: NASA

NASA’s Chandra Reveals Star’s Inner Conflict Before Explosion

NASA - Breaking News - Thu, 08/28/2025 - 12:17pm
This graphic features data from NASA’s Chandra X-ray Observatory of the Cassiopeia A (Cas A) supernova remnant that reveals that the star’s interior violently rearranged itself mere hours before it exploded. The main panel of this graphic is Chandra data that shows the location of different elements in the remains of the explosion: silicon (represented in red), sulfur (yellow), calcium (green) and iron (purple). The blue color reveals the highest-energy X-ray emission detected by Chandra in Cas A and an expanding blast wave. The inset reveals regions with wide ranges of relative abundances of silicon and neon. This data, plus computer modeling, reveal new insight into how massive stars like Cas A end their lives.X-ray: NASA/CXC/Meiji Univ./T. Sato et al.; Image Processing: NASA/CXC/SAO/N. Wolk

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 Observatory

Learn more about the Chandra X-ray Observatory and its mission here:

https://www.nasa.gov/chandra

https://chandra.si.edu

Visual Description

This 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 Contact

Megan 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

Share Details Last Updated Aug 28, 2025 EditorLee MohonContactCorinne M. Beckingercorinne.m.beckinger@nasa.govLocationMarshall Space Flight Center Related Terms Explore More 2 min read Hubble Homes in on Galaxy’s Star Formation

This NASA/ESA Hubble Space Telescope image features a galaxy whose asymmetric appearance may be the…

Article 10 hours ago
4 min read NASA Scientists Help Maryland County Plan to Beat Summer Heat Risks Article 1 day ago 6 min read Meet NASA’s Artemis II Moon Mission Masterminds Article 2 days ago
Categories: NASA

Ripples from the Big Bang could transform our understanding of the universe — and we may be close to detecting them

Space.com - Thu, 08/28/2025 - 12:00pm
It will take the most sensitive instruments ever imagined to reveal ripples from the Big Bang, but they could change our understanding of the entire universe.
Categories: Astronomy

Meet Surya, the 1st-of-its-kind AI model NASA and IBM built to predict solar storms

Space.com - Thu, 08/28/2025 - 11:00am
A new NASA-IBM algorithm called Surya could be a major leap in space weather forecasting.
Categories: Astronomy

10 of the best stargazing locations in North America

Space.com - Thu, 08/28/2025 - 10:00am
Here's where to find very dark skies in the U.S. and Canada.
Categories: Astronomy

Why do we photograph the Milky Way in summer?

Space.com - Thu, 08/28/2025 - 10:00am
The Milky Way is a spectacular sight in the summer skies but why does it look so much more brilliant than it does in the winter?
Categories: Astronomy

NASA debuts new Orion mission control room for Artemis 2 astronaut flight around the moon (photos)

Space.com - Thu, 08/28/2025 - 9:00am
NASA has opened a new Orion Mission Evaluation Room at the Johnson Space Center to analyze in-flight spacecraft data and provide support for Artemis 2 and other future missions to the moon.
Categories: Astronomy

Katie Bisci: Resourcing for Big Science

NASA News - Thu, 08/28/2025 - 8:00am
Deputy Project Manager for Resources – Goddard Space Flight Center Katie Bisci, photographed here with a model of NASA’s Nancy Grace Roman Space Telescope, Credit: NASA/Jolearra Tshiteya

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.

Share Details Last Updated Aug 26, 2025 EditorAshley BalzerLocationGoddard Space Flight Center Related Terms
Categories: NASA

Where no gourd has gone before | Space photo of the day for Aug. 28, 2025

Space.com - Thu, 08/28/2025 - 8:00am
The USS Enterprise, a 'Star Trek' spaceship, is created from pumpkins as part of a German contest.
Categories: Astronomy