A sky-mapping telescope's side project turns up a chemistry survey

SPHEREx, an infrared space telescope NASA launched in March 2025, is best known for a straightforward job: it takes about 3,600 unique images per day to build maps of the entire sky. But in a study published Sept. 28, 2026 in The Astrophysical Journal and announced by NASA on Oct. 8, 2026, scientists turned that all-sky survey toward an unexpected target: brown dwarfs, the dim, free-floating objects that blur the line between stars and planets.

The study authors analyzed SPHEREx observations of 37 nearby brown dwarfs spanning the full brown dwarf temperature range, from about 2,200 degrees Celsius down to roughly minus 20 degrees Celsius, according to NASA's Oct. 8, 2026 news release. The journal abstract describes 33 nearby field brown dwarfs, with additional low-gravity and low-metallicity objects listed separately, which likely accounts for the release's total of 37. The spectra revealed chemically rich atmospheres containing water, carbon dioxide, carbon monoxide and methane, the same roster of molecules found in the giant planets of our own solar system.

What brown dwarfs are, and why 'goth' fits

Brown dwarfs formed from collapsing clouds of gas, like stars do, but they never grew heavy enough to sustain hydrogen fusion in their cores. First discovered in the 1990s, these dimly glowing balls of warm gas share characteristics with Jupiter and Saturn. Unlike most planets, however, they drift in darkness with no host star, heated entirely from within.

Zafar Rustamkulov, lead author of the new study and a scientist at IPAC, Caltech's science and data center in Pasadena, California, described the objects memorably in NASA's release:

"They're kind of goth. Unlike exoplanets, free-floating brown dwarfs are completely independent celestial objects that will fade into eternity alone. We're still learning how complex they are."

The remark is playful, but the underlying point is serious. Only a few dozen brown dwarfs had been studied in detail with space-based telescopes, so much of what astronomers know about their makeup, storminess and evolution has come from theoretical models rather than direct observation.

Why 102 colors and an orbit above the atmosphere matter

SPHEREx measures brightness in 102 different colors of light, from the deepest red visible to human eyes into the infrared, creating a spectrum for each object it observes. It also captures wavelengths that telescopes on the ground cannot see, because water vapor in Earth's atmosphere absorbs them.

Rustamkulov explained the practical consequence in the release:

"From orbit, SPHEREx sees wavelengths of light that are basically impossible to see with telescopes on the ground because water in Earth's atmosphere absorbs them. We are picking up light from the deep, red clouds of brown dwarfs all over the sky."

Those wavelengths matter because molecules carve distinct absorption patterns into infrared light. Those patterns change as brown dwarfs age and cool, which is why a spectrum is effectively a chemical and meteorological report on each object.

Observed data versus model claims

The observed facts in this study are specific: the sample of nearby brown dwarfs was measured; the spectra show signs of water, carbon dioxide, carbon monoxide and methane; and the spectra vary from object to object even at the same temperature. That last point is an observation reported by the study team, not a model output.

What is less settled is the modeling side. Rustamkulov told NASA that the state-of-the-art atmospheric models capture the general chemical trend but struggle in a transition stage of brown dwarf life, when exotic clouds thin out and give way to methane-rich atmospheres.

"The state-of-the-art models are capturing the general chemical trend, but when it comes to these cloudy transitions, the models are struggling to match the data. No two brown dwarfs are alike. Even at the same temperature, their spectra look quite distinct."

In other words, the data are ahead of the models. That is a normal and productive situation in observational science: it tells modelers precisely where their simulations need work.

A laboratory for Jupiter-like weather, open to everyone

For a nontechnical reader, the concrete payoff is access. Brown dwarfs are the closest thing humanity has to a natural laboratory for giant-planet atmospheres like Jupiter's, observed without the glare of a host star. SPHEREx is now imaging thousands of them, where only a few dozen had previously been studied in detail from space.

J. Davy Kirkpatrick, a scientist at Caltech's IPAC and a study coauthor, framed the result as an opening rather than a conclusion:

"We're seeing the signatures of these molecules and how they change from object to object across the entire temperature regime. Our paper concentrated on just three dozen, but we have thousands more that we are in the process of analyzing. I really want to see what bounds the universe places on the variety of brown dwarfs."

Kirkpatrick also acknowledged the humbling scale of the task:

"The findings are a call to action to explore even more of these dark worlds. This journey has turned many of us into accidental meteorologists. We know how hard it is to predict weather on our own planet, and we realize it's going to be just as challenging to explain the phenomena we see in these bizarre, cold objects."

Open data as the quiet headline

Spotting brown dwarfs is, by NASA's own description, a side project for SPHEREx. The mission's primary science is cosmological: knowing where hundreds of millions of galaxies are distributed across the cosmos will help scientists reconstruct conditions in the first fraction of a second after the big bang. The telescope also searches for the chemical ingredients of life and maps interstellar ice.

Notably, NASA states that the SPHEREx dataset is freely available to scientists and the public. That openness is what makes the difference between a mission detail and a genuine shift: a curious reader or an independent researcher can now examine spectra for thousands of brown dwarfs, a scale of access that simply did not exist when the subject list numbered in the dozens.

It is worth being precise about what has and has not changed. What has changed is coverage: a large, uniform, all-sky spectral survey of these objects. What has not changed is resolution; SPHEREx's spectra are broader and coarser than targeted observations from telescopes like Webb. The most likely trajectory is complementary rather than competitive: SPHEREx finds and characterizes thousands of candidates, and pointed instruments follow up on the most intriguing ones.

How we know what we know

This article is based on the NASA/JPL news release published Oct. 8, 2026, which this desk retrieved and verified, and on NASA's official SPHEREx mission page. The Astrophysical Journal paper was published Sept. 28, 2026, and its abstract page was verified by independent editorial review, confirming the lead author (Rustamkulov), a coauthor (Kirkpatrick), the paper title and open-access status. The underlying study's claims as summarized here rest on the NASA release and the abstract; the full paper was not independently reviewed line by line, and we flag that as a limitation rather than presenting full verification of the underlying research.

NASA and JPL are the source of the research described, and statements about the mission's capabilities come from the agencies that built and operate it, which are interested parties in their own publicity. The observation of weather-like phenomena in brown dwarf atmospheres is established science going back to the Spitzer and Hubble era; what is new here is scale and spectral coverage, not the basic idea. Opinions about the trajectory of the field, including the complementary-instrument framing in the section above, are this desk's assessment and are labeled as such.