NASA’s Chandra X-ray Observatory marked America’s 250th birthday with a set of four cosmic portraits, all rendered in red, white and blue, along with three new audio versions of the same data. The collection was published on June 30, 2026, four days before the Fourth of July, and pulls together an exploded star, a stellar nursery, a spiral galaxy and a distant galaxy cluster whose gravity bends light from objects behind it.
The four objects span the kinds of cosmic scenes NASA studies. They also happen to color-map cleanly to the U.S. flag, which is why Chandra’s team chose them for the holiday release. Each image combines X-ray light with infrared, optical or ultraviolet light from other space telescopes, and three of them now have matching soundtracks that turn brightness into volume and X-ray sources into individual notes.
What NASA Released on June 30
NASA published the red, white, and blue set on June 30, 2026, with the official Chandra gallery listing the four images in order: Cassiopeia A, NGC 3603, NGC 4736 (also known as Messier 94) and the galaxy cluster ZwCl 0024+1652. Cassiopeia A fills the top panel of the mosaic, while the other three make up the bottom row.
Three new sonifications were released at the same time, for NGC 3603, NGC 4736 and ZwCl 0024+1652. A sonification of Cassiopeia A had already been released previously and is still available on the Chandra site. The sonification work is led by the Chandra X-ray Center and is part of NASA’s Universe of Learning program, according to the Chandra release.
The Four Cosmic Objects, From Nearest to Farthest
The four targets were chosen to cover a spread of astronomical settings, from a nearby exploded star to a galaxy cluster whose light left it when Earth was young. The distances range from 11,000 light-years for Cassiopeia A to 4 billion light-years for ZwCl 0024+1652, according to the Chandra release page and Space.com’s reporting on it.
Cassiopeia A is the shredded remains of a massive star that astronomers believe was 15 to 25 times more massive than the sun. The light from its explosion reached Earth in the 17th century, though the star itself lies about 11,000 light-years away. The Chandra release describes the object as the leftover gas from that supernova, with X-ray data revealing the blast wave and elements such as iron, calcium and oxygen in the debris field.
NGC 3603 sits about 20,000 light-years from Earth in the Carina spiral arm of the Milky Way. Chandra calls it a colossal and brilliant star factory. The nebula wraps a dense cluster of massive young stars whose radiation and stellar winds sculpt the surrounding gas and dust. NASA has described it as containing some of the most massive stars in the known universe.
NGC 4736, also catalogued as Messier 94, is a spiral galaxy roughly 16 million light-years away in the constellation Canes Venatici. Its defining feature is a bright inner starburst ring where new stars are forming, possibly fed by gas driven in from a bar-like oval structure. NASA notes that the galaxy is unusual for its curious lack of dark matter, which is why it has been the subject of extensive follow-up study.
| Object | Type | Distance | What the image reveals |
|---|---|---|---|
| Cassiopeia A | Supernova remnant | About 11,000 light-years | Blast wave and debris from a star 15 to 25 times more massive than the sun |
| NGC 3603 | Nebula and star cluster in the Carina spiral arm | About 20,000 light-years | Massive young stars and the gas and dust they are sculpting |
| NGC 4736 (Messier 94) | Spiral galaxy | About 16 million light-years | Starburst ring of new star formation around a galaxy oddly short on dark matter |
| ZwCl 0024+1652 | Galaxy cluster in Pisces | About 4 billion light-years | Superheated gas between galaxies and a dark matter map from gravitational lensing |
ZwCl 0024+1652 sits in Pisces at roughly 4 billion light-years from Earth, far enough back that the cluster’s own light was already on its way when the first multicellular life was forming here. The cluster is bound together by gravity, and Chandra’s X-ray data shows the enormous reservoir of superheated gas that fills the space between its galaxies, gas that holds far more mass than the galaxies themselves.
How Red, White and Blue Get Built From Real Light
The patriotic palette is not painted on. Each image is a layered combination of light from multiple telescopes, and the colors map to specific wavelengths. Chandra’s X-ray view is overlaid with infrared from the James Webb Space Telescope, or with optical, infrared and ultraviolet light from the Hubble Space Telescope, or in one case with a visible-light image taken from the ground by amateur astrophotographers Brian Brennan and Remi Lacasse.
For Cassiopeia A, Chandra’s X-ray data is shown in blue and purple while JWST’s infrared data appears in red and white. For NGC 3603, Chandra’s X-ray contribution shows up in red and white, and Hubble’s optical, infrared and ultraviolet data are layered in red-orange, green, blue and yellow. The way those wavelengths combine gives the nebula and its young stars a predominantly red, white and blue look.
NGC 4736 uses Chandra X-ray data in red, orange and blue, with the ground-based visible-light image mapped in red, green and blue. ZwCl 0024+1652 splits the work between Chandra X-ray for the superheated gas in red and Hubble for both the galaxies and a specially processed map of dark matter rendered in blue, with individual galaxies in yellow and white. Image processing for all four was credited to L. Frattare and K. Arcand at the Chandra X-ray Center, with additional dark matter processing by M. J. Jee.
Hearing the Data: Three New Sonifications
The same images now have sound. Chandra released three new sonification tracks for NGC 3603, NGC 4736 and ZwCl 0024+1652, with Cassiopeia A’s sonification already in the archive. In a Chandra video, the team explains that brightness drives volume and that different kinds of light are mapped to different instruments.
The work was led by visualization scientist Kimberly Arcand of the Chandra X-ray Center, with SYSTEM Sounds collaborators Matt Russo, an astrophysicist, and Andrew Santaguida, a musician. Christine Malec is credited as a consultant on the project.
- NGC 3603: a left-to-right scan where Chandra’s compact X-ray sources become piano notes, diffuse X-ray emission stretches across audio frequencies and Hubble’s optical data plays as sustained tones and acoustic guitar harmonics.
- NGC 4736: a clockwise radar-style scan where Chandra X-rays become wind-like sounds, neutron stars and stellar-mass black holes detected by Chandra are pitched tones on a glass marimba and ground-based optical data becomes a low drone with stars and background galaxies as soft piano notes.
- ZwCl 0024+1652: a circular scan that moves inward, peaking in volume as it passes over the dark matter detected by Hubble and again as it reaches the cluster’s core; background stars play as a swelling glockenspiel-like sound, galaxies as piano and the dominant central X-ray emission as airy synthesizer notes.
The full set of audio-only downloads in mp3, ogg and wav formats is hosted on Chandra’s site, with separate all-wavelengths, X-ray-only, optical-only and dark-matter-only versions for ZwCl 0024+1652.
Why These Four, and Why This Week
The curation was deliberate. The four targets cover the kinds of cosmic objects NASA studies, from a dead star to a galaxy cluster, and their underlying light just happens to combine into a patriotic palette. The Chandra team frames the set as a vivid gallery of American-led discovery, bridging the gap between the stars and the nation that reached for them.
Who needs backyard fireworks when you have supernova remnants and supermassive black holes putting on a show?
That line opens the Chandra release video, narrated by the team, ahead of the sonifications. The timing lines up with the Fourth of July, and the video closes with a simple “Happy 4th!” from the Chandra X-ray Center.
The Collaboration Behind the Release
NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts. The release credits L. Frattare and K. Arcand for image processing, with Kimberly Arcand driving the sonification coordination through NASA’s Universe of Learning program.
The collection sits alongside other ongoing NASA work on aging observatories, including the agency’s separate push to rescue the Swift space telescope from a falling orbit. Chandra itself has been in operation since 1999, and its combination of X-ray vision with Hubble and JWST data is the reason a single release can pull together a supernova, a nursery, a spiral and a galaxy cluster in one frame.
The four images and the three new audio tracks are available on the Chandra site, with the full mosaic and individual files for each object.
