by Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on exciting discoveries, scientific advances and more.
A bright supernova remnant, a nebula shaped like a cat’s paw and the iconic “Pillars of Creation” are just some of the celestial objects shining in 25 never-before-seen images captured by NASA’s Chandra X-ray Observatory to show the mark a telescope. 25 years.
Chandra, named in honor of Indian American astrophysicist Subrahmanyan Chandrasekhar, launched into space aboard the space shuttle Columbia on July 23, 1999. The crew, including STS-93 Commander Eileen Collins, deployed the telescope into its oval orbit, it takes Chandra on a path around the Earth that is almost one-third the distance to the moon.
“On behalf of the STS-93 crew, we are incredibly proud of the Chandra X-ray Observatory and its amazing team that built and launched this astronomical treasure,” Collins said in a statement shared Monday in a NASA release. “Chandra’s discoveries have continued to surprise and impress us over the past 25 years.”
To date, Chandra has taken nearly 25,000 observations of the universe.
The telescope observes the cosmos through X-ray light, which is invisible to the human eye. X-rays are emitted by some of the most energetic events and hottest objects in the universe, including exploding stars, matter swirling around black holes, galaxy collisions and even exoplanets.
“For a quarter of a century, Chandra has made discovery after amazing discovery,” said Pat Slane, director of the Chandra X-ray Center at the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts, in a statement. “Astronomers have used Chandra to investigate mysteries we didn’t even know about when we built the telescope – including exoplanets and dark energy.”
But the telescope’s future could be in jeopardy due to NASA budget cuts, which threaten to bring the mission to a premature end by the end of this decade. And without another world-class X-ray observatory to immediately take its place, astronomical research could suffer.
Revealing the hidden universe
The idea for the Chandra mission was first proposed in 1976 by astrophysicists Riccardo Giacconi and Harvey Tananbaum, who saw the importance of a large X-ray telescope and began its design. Along with the Hubble Space Telescope and the now retired Spitzer Space Telescope and the Compton Gamma Ray Observatory, Chandra is one of NASA’s “Great Observatories” launched near the turn of the 20th century designed to study the universe across different wavelengths of light.
The telescope has the highest-quality X-ray mirrors ever manufactured, resulting in not only gorgeous imagery, but the ability to identify detailed structures that reflect the fundamental physics of energetic cosmic objects, Ballyslane said.
During its mission, Chandra studied the remnants of exploding stars to see how matter and energy behave in space under the most extreme conditions.
Shortly after launch, the observatory focused on what has become an iconic celestial target: the supernova remnant Cassiopeia A. Chandra has returned to this feature time and time again, revealing new insights each time.
The remnant is an expanding cloud of matter and energy released when a star explodes. Over time, Chandra X-ray data on the remnant allowed astronomers to discover a dense neutron star left by the explosion at the center of the remnant, as well as a “superfluid” found inside the neutron star. The liquid suggests that the original massive star may have been turned inside out as it exploded, helping astronomers better understand the violent evolution of stars.
The observatory has also witnessed the birth of stars in the Cat’s Paw Nebula and the famous “Pillars of Creation” and peered into the heart of our own Milky Way galaxy to help astronomers study the supermassive black hole at its center. And Chandra has spied huge galaxy clusters including hundreds of thousands of twinkling galaxies, as well as the soup of superheated gas around the galaxies that can only be seen in X-ray light.
“Before Chandra, it was known that there was a kind of diffuse nebula of X-ray emissions coming from all directions in the sky. Along with Chandra, we now know that this is not a dove at all; it’s a large collection of distant black holes whose emissions merge into fainter telescopes,” Slane said.
“There are hundreds of examples like this, where Chandra’s sensitivity has led to new discoveries or confirmed existing theories,” he said. “The legacy is not just a single discovery, it is the unique contribution to the study of objects as close to the planets in our Solar System as to supermassive black holes near the edge of time.”
With more than 10,000 scientific papers written based on Chandra data, the telescope is one of NASA’s most productive astrophysics missions.
An uncertain future
NASA’s budget can’t support all of its current programs while starting new projects planned for the future, so some legacy missions like Chandra will face cuts, Slane said.
“Speaking for Chandra, the cuts would fall somewhere between severely reducing the observatory’s scientific productivity and support for its user community, or closing the observatory,” he said. “It’s true that NASA doesn’t want to do the latter, and the public — and Congress — are saying that funding to NASA’s Great Observatory, which is still healthy and produces great science, has not been cut, and there is no replacement in sight. NASA is now working to consider the overall budget situation and provide a final guidance for Chandra.”
Members of the astronomy community have created a community campaign called Save Chandra to raise awareness and support for the future of the telescope.
NASA’s budget allocation for Chandra will gradually decrease over the coming years, based on the agency’s budget request released in March. While the telescope received $68.3 million in 2023, Chandra would receive only $41.1 million for operations beginning in fiscal year 2025. The budget allocation for Chandra will then drop to $26.6 million per year beginning in fiscal year 2026 and at through fiscal year 2028, and then. drop to just $5.2 million in fiscal year 2029, effectively ending the mission.
Despite spending 25 years in space, Chandra is still in good health and almost all of the spacecraft’s systems are in good condition, Ballyslane said. If any issues have arisen, such as trying to keep the telescope at its cool, optimal operating temperature, the Chandra team has found creative problems that haven’t reduced the telescope’s effectiveness, he said. And there are no worries about the telescope running out of fuel.
Although successor telescope concepts are in mind to take Chandra’s place, such as the Lynx X-ray Observatory, with better imaging capabilities, the development of these instruments has not been chosen as a top priority, so there is no current X-ray observatory . step in the event that the Chandra mission comes to fruition at the end of the decade.
Chandra plays a key role not only as an X-ray telescope, but in providing data that pairs with observations from other telescopes. Together, all these wavelengths of light provide a more complete picture that enables astronomers to solve the long-standing mysteries of the universe. In addition, the loss of the telescope would affect the next generation of X-ray astronomers who receive support from Chandra for their research.
“The loss of Chandra, right now, would be catastrophic not just for X-ray astronomy, but for most of astronomy,” Slane said. “In addition to continuing to produce advanced science – operation over the next decade would provide a framework within which NASA could plan for the continuation and natural growth of the US X-ray astronomy program.”
For more CNN news and newsletters create an account at CNN.com
