SPACE/COSMOS
E.L.O.N. MUSK'S TECK BRO
US Senate confirms Jared Isaacman as NASA chief amid budget cuts and moon race
The US Senate has confirmed billionaire private astronaut Jared Isaacman as NASA administrator, installing a strong advocate of Mars missions to lead the space agency as it faces deep budget cuts and intensifying competition with China to return humans to the Moon.
Issued on: 18/12/2025
By: FRANCE 24
The US Senate on Wednesday confirmed billionaire private astronaut Jared Isaacman to become President Donald Trump’s NASA administrator, making an advocate of Mars missions and a former associate of SpaceX chief executive Elon Musk the space agency’s 15th leader.
The vote on Isaacman, who Trump removed and then renamed as NASA administrator nominee this year, passed 67–30, two weeks after he told senators in his second hearing that NASA must pick up the pace in beating China back to the Moon this decade.
Isaacman will lead an agency of 14,000 employees as it invests billions of dollars into its most ambitious space exploration endeavour yet: returning humans to the Moon to seed a long-term presence on the surface before eventually sending astronauts to Mars.
NASA workforce cut in efficiency push
The White House, in its government efficiency push led by Musk, slashed NASA’s workforce by 20 percent and has sought to cut the agency’s 2026 budget by roughly 25 percent from its usual $25 billion, imperilling dozens of space science programmes that scientists and some officials regard as priorities.
Isaacman envisions a revamped focus on sending missions to Mars on top of the Artemis Moon effort, as well as a greater dependence on private companies such as SpaceX to save taxpayer money and stimulate private-sector competition.
Of the 67 votes in Isaacman’s favour, 16 were from Democrats, joining 51 from Republicans. All 30 votes against his confirmation were from Democrats.
Maria Cantwell, the ranking member of the Senate Commerce Committee that oversees NASA, has criticised the Trump administration’s efforts to cut NASA’s science unit. She supported Isaacman’s confirmation on Wednesday.
“During his nomination process, Mr Isaacman emphasised the importance of developing a pipeline of future scientists, engineers, researchers and astronauts to support the science and technology development and align with NASA’s objectives. I strongly agree,” Cantwell said.
Some Democratic senators said during Isaacman’s hearing on December 3 that they were concerned about his closeness to Musk, whose company holds about $15 billion in NASA contracts and could benefit from certain policies Isaacman has advocated.
Musk advocated for Isaacman’s nomination when Trump was elected in 2024. Musk had sought to realign the US space programme with a greater focus on Mars during his stint as a close adviser to Trump.
Senate Republicans and some Democrats, including Cantwell, have also stressed urgency in NASA’s Moon race with China, which is aiming to send its astronauts to the lunar surface by 2030. NASA faces a shaky target of 2028 using its Space Launch System rocket and SpaceX’s giant Starship rocket, under development, as the lander.
Acting NASA chief Sean Duffy, who also leads the US Transportation Department, congratulated Isaacman on X, wishing him “success as he begins his tenure and leads NASA as we go back to the Moon in 2028 and beat China”.
(FRANCE 24 with Reuters)
Possible "superkilonova" exploded not once but twice
Double explosion may have produced gravitational waves and light
California Institute of Technology
image:
This artist's concepts shows a hypothesized event known as a superkilonova. A massive star explodes in a supernova (left), which generates elements like carbon and iron. In the aftermath, two neutron stars are born (middle), at least one of which is believed to be less massive than our Sun. The neutron stars spiral together, sending gravitational waves rippling through the cosmos, before merging in a dramatic kilonova (right). Kilonovae seed the universe with the heaviest elements, such as gold at platinum, which glow with red light.
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Credit: Caltech/K. Miller and R. Hurt (IPAC)
When the most massive stars reach the ends of their lives, they blow up in spectacular supernova explosions, which seed the universe with heavy elements such as carbon and iron. Another type of explosion—the kilonova—occurs when a pair of dense dead stars, called neutron stars, smash together, forging even heavier elements such as gold and uranium. Such heavy elements are among the basic building blocks of stars and planets.
So far, only one kilonova has been unambiguously confirmed to date, a historic event known as GW170817, which took place in 2017. In that case, two neutron stars smashed together, sending ripples in space-time, known as gravitational waves, as well as light waves across the cosmos. The cosmic blast was detected in gravitational waves by the National Science Foundation's Laser Interferometer Gravitational-wave Observatory (LIGO) and its European partner, the Virgo gravitational-wave detector, and in light waves by dozens of ground-based and space telescopes around the world.
Now, astronomers are reporting evidence for a possible second kilonova event, but the case is not closed. In fact, this situation is much more complex because the candidate kilonova, named AT2025ulz, is thought to have stemmed from a supernova blast that went off hours before, ultimately obscuring astronomers' view.
"At first, for about three days, the eruption looked just like the first kilonova in 2017," says Caltech's Mansi Kasliwal (PhD '11), professor of astronomy and director of Caltech's Palomar Observatory near San Diego. "Everybody was intensely trying to observe and analyze it, but then it started to look more like a supernova, and some astronomers lost interest. Not us."
Kasliwal is lead author of a new study describing the findings in The Astrophysical Journal Letters. In the report, she and her colleagues describe evidence that this oddball event may be a first-of-its-kind superkilonova, or a kilonova spurred by a supernova. Such an event has been hypothesized but never seen.
Evidence for the possible rarity first came on August 18, 2025, when the twin detectors of LIGO in Louisiana and Washington, as well as Virgo in Italy, picked up a new gravitational-wave signal. Within minutes, the team that operates the gravitational-wave detectors (an international collaboration that also includes the organization that runs the KAGRA detector in Japan) sent an alert to the astronomical community letting them know that gravitational waves had been registered from what appeared to be a merger between two objects, with at least one of them being unusually tiny. The alert included a rough map of the source's location.
"While not as highly confident as some of our alerts, this quickly got our attention as a potentially very intriguing event candidate," says David Reitze, the executive director of LIGO and a research professor at Caltech. "We are continuing to analyze the data, and it's clear that at least one of the colliding objects is less massive than a typical neutron star."
A few hours later, the Zwicky Transient Facility (ZTF), a survey camera at Palomar Observatory, was the first to pinpoint a rapidly fading red object 1.3 billion light-years away, which is thought to have originated in the same location as the source of gravitational waves. The event, initially called ZTF 25abjmnps, was later renamed AT2025ulz by the International Astronomical Union Transient Name Server.
About a dozen other telescopes set their sights on the target to learn more, including the W. M. Keck Observatory in Hawaiʻi, the Fraunhofer telescope at the Wendelstein Observatory in Germany, and a suite of telescopes around the world that were previously part of the GROWTH (Global Relay of Observatories Watching Transients Happen) program, led by Kasliwal.
The observations confirmed that the eruption of light had faded fast and glowed at red wavelengths—just as GW170817 had done eight years earlier. In the case of the GW170817 kilonova, the red colors came from heavy elements like gold; these atoms have more electron energy levels than lighter elements, so they block blue light but let red light pass through.
Then, days after the blast, AT2025ulz started to brighten again, turn blue, and show hydrogen in its spectra—all signs of a supernova not a kilonova (specifically a "stripped-envelope core-collapse" supernova). Supernovae from distant galaxies are generally not expected to generate enough gravitational waves to be detectable by LIGO and Virgo, whereas kilonovae are. This led some astronomers to conclude that AT2025ulz was triggered by a typical ho-hum supernova and not, in fact, related to the gravitational-wave signal.
What Might Be Going On?
Kasliwal says that several clues tipped her off that something unusual had taken place. Though AT2025ulz did not resemble the classic kilonova GW170817, it also did not look like an average supernova. Additionally, the LIGO–Virgo gravitational-wave data had revealed that at least one of the neutron stars in the merger was less massive than our Sun, a hint that one or two small neutron stars might have merged to produce a kilonova.
Neutron stars are the leftover remains of massive stars that explode as supernovae. They are thought to be around the size of San Francisco (about 25 kilometers across) with masses that range from 1.2 to about three times that of our Sun. Some theorists have proposed ways in which neutron stars might be even smaller, with masses less than the Sun's, but none have been observed so far. The theorists invoke two scenarios to explain how a neutron could be that small. In one, a rapidly spinning massive star goes supernova, then splits into two tiny, sub-solar neutron stars in a process called fission.
In the second scenario, called fragmentation, the rapidly spinning star again goes supernova, but, this time, a disk of material forms around the collapsing star. The lumpy disk material coalesces into a tiny neutron in a manner similar to how planets form.
With LIGO and Virgo having detected at least one sub-solar neutron star, it is possible, according to theories proposed by co-author Brian Metzger of Columbia University, that two newly formed neutron stars could have spiraled together and crashed, erupting as a kilonova that sent gravitational waves rippling through the cosmos. As the kilonova churned out heavy metals, it would have initially glowed in red light as ZTF and other telescopes observed. The expanding debris from the initial supernova blast would have obscured the astronomers’ view of the kilonova.
In other words, a supernova may have birthed twin baby neutron stars that then merged to make a kilonova.
"The only way theorists have come up with to birth sub-solar neutron stars is during the collapse of a very rapidly spinning star," Metzger says. "If these 'forbidden' stars pair up and merge by emitting gravitational waves, it is possible that such an event would be accompanied by a supernova rather than be seen as a bare kilonova."
But while this theory is tantalizing and interesting to consider, the research team stresses that there is not enough evidence to make firm claims.
The only way to test the superkilonovae theory is to find more. "Future kilonovae events may not look like GW170817 and may be mistaken for supernovae," Kasliwal says. "We can look for new possibilities in data like this from ZTF as well as the Vera Rubin Observatory, and upcoming projects such as NASA's Nancy Roman Space Telescope, NASA's UVEX [led by Caltech's Fiona Harrison], Caltech's Deep Synoptic Array-2000, and Caltech’s Cryoscope in the Antarctic. We do not know with certainty that we found a superkilonova, but the event nevertheless is eye opening."
The paper, titled "ZTF25abjmnps (AT2025ulz) and S250818k: A Candidate Superkilonova from a Sub-threshold Sub-Solar Gravitational Wave Trigger," was funded by the Gordon and Betty Moore Foundation, the Knut and Alice Wallenberg Foundation, the National Science Foundation (NSF), the Simons Foundation, the US Department of Energy, a McWilliams Postdoctoral Fellowship, and the University of Ferrara in Italy. Other Caltech authors include Tomás Ahumada (now at NOIRLab, Chile), Viraj Karambelkar (now at Columbia University), Christoffer Fremling, Sam Rose, Kaustav Das, Tracy Chen, Nicholas Earley, Matthew Graham, George Helou, and Ashish Mahabal.
Caltech's ZTF is funded by the NSF and an international collaboration of partners. Additional support comes from the Heising-Simons Foundation and from Caltech. ZTF data are processed and archived by IPAC, an astronomy center at Caltech.
Journal
The Astrophysical Journal Letters
NASA’s Webb telescope finds bizarre atmosphere on a lemon-shaped exoplanet
University of Chicago
image:
This artist’s concept shows what the exoplanet called PSR J2322-2650b (left) may look like as it orbits a rapidly spinning neutron star called a pulsar (right). Gravitational forces from the much heavier pulsar are pulling the Jupiter-mass world into a bizarre lemon shape.
view moreCredit: NASA, ESA, CSA, Ralf Crawford (STScI)
Scientists using NASA’s James Webb Space Telescope have observed an entirely new type of exoplanet whose atmospheric composition challenges our understanding of how this type of planet forms.
This bizarre, lemon-shaped body, possibly containing diamonds at its core, blurs the line between planets and stars.
Officially named PSR J2322-2650b, this object has an exotic helium-and-carbon-dominated atmosphere unlike any ever seen before. It has a mass about the same as Jupiter, but soot clouds float through the air—and deep within the planet, these carbon clouds can condense and form diamonds. It orbits a rapidly spinning neutron star.
How the planet came to be is a mystery.
“The planet orbits a star that's completely bizarre — the mass of the Sun, but the size of a city,” explained the University of Chicago’s Michael Zhang, the principal investigator on this study, which is accepted for publication in The Astrophysical Journal Letters. “This is a new type of planet atmosphere that nobody has ever seen before.”
“This was an absolute surprise,” said team member Peter Gao of the Carnegie Earth and Planets Laboratory in Washington, D.C. “I remember after we got the data down, our collective reaction was ‘What the heck is this?’”
A bizarre pair
The new planet, PSR J2322-2650b, is orbiting a rapidly spinning neutron star, also known as a pulsar.
This star emits beams of electromagnetic radiation from its magnetic poles at regular intervals just milliseconds apart. But the star is emitting mostly gamma rays and other high-energy particles, which are invisible to the Webb telescope’s infrared vision.
This means scientists can study the planet in intricate detail across its whole orbit—normally an extremely difficult task, because stars usually far outshine their planets.
“This system is unique because we are able to view the planet illuminated by its host star, but not see the host star at all,” explained Maya Beleznay, a graduate student at Stanford University who worked on modelling the shape of the planet and the geometry of its orbit. “So we get a really pristine spectrum. And we can better study this system in more detail than normal exoplanets.”
Taking stock of the planet, the team was surprised.
“Instead of finding the normal molecules we expect to see on an exoplanet—like water, methane and carbon dioxide—we saw molecular carbon, specifically C3 and C2,” said Zhang.
At the core of the planet, subjected to intense pressure, it’s possible this carbon could be squeezed into diamonds.
But to the scientists, the larger question is how such a planet could have formed at all.
“It's very hard to imagine how you get this extremely carbon-enriched composition,” said Zhang. “It seems to rule out every known formation mechanism.”
‘A puzzle to go after’
PSR J2322-2650b is extraordinary close to its star, just 1 million miles away. In contrast, the Earth’s distance from the Sun is about 100 million miles.
Because of its extremely tight orbit, the exoplanet’s entire year—the time it takes to go around its star—is just 7.8 hours.
Applying models to the planet’s brightness variations over its orbit, the team finds that immense gravitational forces from the much heavier pulsar are pulling the Jupiter-mass planet into a lemon shape.
Together, the star and exoplanet may be considered a “black widow” system. Black widows are a rare type of system where a rapidly spinning pulsar is paired with a small, low-mass companion. In the past, material from the companion would have streamed onto the pulsar, causing it to spin faster over time, which powers a strong wind. That wind and radiation then bombard and evaporate the smaller and less massive star.
Like the spider for which it is named, the pulsar slowly consumes its unfortunate partner.
But in this case, the tiny companion is officially considered an exoplanet by the International Astronomical Union, not a star.
“Did this thing form like a normal planet? No, because the composition is entirely different,” said Zhang. “Did it form by stripping the outside of a star, like ‘normal’ black widow systems are formed? Probably not, because nuclear physics does not make pure carbon.”
Team member Roger Romani, of Stanford and the Kavli Institute for Particle Astrophysics and Cosmology Institute, is one of the world’s preeminent experts on black widow systems. He proposes one evocative phenomenon that could occur in the unique atmosphere.
“As the companion cools down, the mixture of carbon and oxygen in the interior starts to crystallize,” Romani theorized. “Pure carbon crystals float to the top and get mixed into the helium, and that's what we see. But then something has to happen to keep the oxygen and nitrogen away. And that's where there's controversy.”
“But it's nice to not know everything,” said Romani. “I'm looking forward to learning more about the weirdness of this atmosphere. It's great to have a puzzle to go after.”
With its infrared vision and exquisite sensitivity, this is a discovery only the Webb telescope could make. Its perch a million miles from Earth and its huge sunshield keeps the instruments very cold, which is necessary for conducting these observations.
“On the Earth, lots of things are hot, and that heat really interferes with the observations because it's another source of photons that you have to deal with,” explained Zhang. “It's absolutely not feasible from the ground.”
Other UChicago scientists on the study included Prof. Jacob Bean, graduate student Brandon Park Coy and Rafael Luque, who was then a postdoctoral researcher at UChicago and is now with the Instituto de Astrofísica de Andalucía in Spain.
Citation: “A carbon-rich atmosphere on a windy pulsar planet.” Zhang et al, The Astrophysical Journal Letters, accepted for publication.
Funding: NASA, Heising-Simons Foundation.
Exoplanet PSR J2322-2650b Orbiting a Pulsar [VIDEO]
This animation shows an exotic exoplanet orbiting a distant pulsar, or rapidly rotating neutron star with radio pulses. The planet, which orbits about 1 million miles away from the pulsar, is stretched into a lemon shape by the pulsar’s strong gravitational tides.
Credit
NASA, ESA, CSA, Ralf Crawford (STScI)
Journal
The Astrophysical Journal Letters
Article Title
A Carbon-rich Atmosphere on a Windy Pulsar Planet
Article Publication Date
16-Dec-2025
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