2 March 2026

Today’s Visualized takes a good look at our galaxy. But first, catch up on the latest science news, including caterpillars that keep a beat and the surprising notes one historian found in the margins of an old astronomy book.

Microbiology | Science

A gut check on gut health

Movies about high school teach us that bullies are stronger in a pack. So too are gut microbes, finds new research published in Science.

To study conditions like inflammatory bowel disease and irritable bowel syndrome, scientists aimed to build a computer model that could simulate how bacteria interact in the gut. Two clear modes arose: One where a diverse group of bacteria competed for resources, and one where a small group of bacteria cooperated for resources. Curious, the researchers compared their model results with DNA from patients, and found that the competitive state correlated with health, while the cooperative state—like bullies teaming up—signaled disease.

They dubbed the new competitive-cooperative metric the Ecological Network Balance Index. The metric could successfully identify healthy versus diseased patients, including those with colorectal cancer. In the future, suggest the authors, the metric could be applied to stool samples for a quick gut check on a patient’s gut health. And the finding justifies why fecal transplants are so successful; the patient gets a whole, interactive community of bacteria, rather than one or two species.

“This gives us a new way to think about what goes wrong in the microbiome,” said author Martin Blaser in a statement. “Instead of focusing on individual microbes, it shows that disease emerges when the entire system shifts. That opens the door to earlier detection and more targeted interventions.”

Read the paper

Animals | Annals of the New York Academy of Sciences

Caterpillars dance to the beat of their ants’ drum

An ant carrying a Maculinea caterpillar. Vibrant Lab, Torino

Much like knowing the right song to sing along to at a party, some caterpillars fit in with ants by matching their rhythm. Lycaenid butterfly caterpillars are known “myrmecophiles,” or ant-lovers. Ants bring young caterpillars into their nests, protect them from predators, and sometimes feed them. In exchange, the caterpillars secrete sugary droplets or chemically imitate the colony’s scent.

Now, researchers have found that some caterpillars also communicate through precisely structured vibrations. “ For caterpillars, getting the rhythm right can be vital: It may determine whether ants provide care and protection, or ignore them completely,” said biologist Francesca Barbero in a statement.

The team recorded substrate-borne vibrations—signals traveling through soil and plant stems—from two ant species and nine species of lycaenid caterpillars that vary in how strongly they depend on ants. To capture their signals, researchers placed caterpillars and their host ants on a custom-built recording device inside an anechoic chamber. A highly sensitive miniature microphone detected substrate-borne vibrations, while a second microphone recorded ambient noise to cancel inference.

The researchers then analyzed the temporal structure of the signals, measuring features such as the evenness of spacing between pulses and the presence of “double meter,” an alternating strong-weak beat pattern. The most ant-dependent caterpillars produced the most rhythmically complex signals. Their vibrations showed regular timing and beatlike structure similar to the ants’ own signals. Species with weaker or no association with ants produced simpler, less regular patterns.

“Complex rhythmic organization has been mainly seen in primates, so for us to find that even ants and caterpillars rely on carefully timed rhythmic signals to communicate is very exciting,” said primatologist Chiara De Gregorio.

Read the Paper

History of Science | News from Science

Notes in the margins—‘I can’t believe my eyes!’

On a cloudy day this past January, historian Ivan Malara sat in Italy’s National Central Library of Florence poring over seven 16th century printings of the ancient world’s most influential astronomy text. The pages belonged to The Almagest, in which second century polymath Claudius Ptolemy described his vision of an Earth-centered cosmos. As Malara flipped through the pages, he spotted something out of place. Someone had transcribed Psalm 145 on an otherwise blank page—in handwriting reminiscent of a very, very famous Tuscan astronomer.

That book, Malara came to realize, had been annotated by none other than Galileo Galilei. “Forgive the awkward hour ,” he wrote from his hotel room, dashing off an email to two of Italy’s leading Galileo scholars, “but I can’t believe my eyes!” The discovery promises new insights into one of the most famous ideological transitions in the history of science: the moment when Earth was thrust from the center of our universe.

It’s rare enough to link an entire new book to the textual record of Galileo. But Ptolemy’s Almagest wasn’t just any old book. If Galileo today is often praised for rejecting the authority of ancient wisdom, TheAlmagest—whose description of a geocentric cosmos reigned over Western astronomy for 14 centuries—was that ancient wisdom incarnate. The annotated version of The Almagest offers a more nuanced portrait: the revolutionary as a young man.

Written around 1590, roughly 2 decades before his groundbreaking telescope observations of the Moon and Jupiter, Galileo’s notes reveal someone who both revered and critically dissected Ptolemy’s work. And they imply, Malara argues, that Galileo ultimately broke with Ptolemy’s cosmos because his mastery of it convinced him that a heliocentric system would better fulfill Ptolemy’s own logic. That interpretation contrasts with the typical portrayal of Galileo as being motivated by philosophy or even political savvy—not careful math.

See the notes

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Visualized

The Central Molecular Zone of the Milky Way

The Milky Way’s Central Molecular Zone. Longmore et al./ALMA (ESO/NAOJ/NRAO); Background: Minniti et al./ESO

The center of our Milky Way galaxy is chock full of cold molecular gas and dust, the building blocks of stars. The Atacama Large Millimeter Array (ALMA), an array of 66 radio telescopes in Chile’s Atacama Desert, has now published a uniquely big image of a tantalizing region within it: the Central Molecular Zone (CMZ), which houses up to 80% of the Milky Way’s dense gas. The image, spanning more than 650 light-years, gives scientists a fresh look into how billions of stars are born.

Before the image, “It was like having a few snapshots of individual streets but no map of the city,” Steven Longmore, principal investigator of the ALMA project that took the image, told The Guardian. “We could see gas here, a star-forming cloud there, but we were missing how it was all connected.”

To take the image, scientists stitched together individual snapshots taken over many long observation sessions. Radio telescopes like ALMA are best suited to studying this Milky Way region since all its gas obscures many other wavelengths of light.

The snapshot shows filaments of gas stretching light-years across, as well as small gas clouds enveloping individual stars. Researchers could detect dozens of different molecules throughout the CMZ, including complex organics like methanol, acetone, and ethanol. At any given moment, some of this gas is zooming around at hundreds of thousands of miles per hour, while other regions sit calmly. Scientists think the gassy processes of star formation occurring in the CMZ could mirror those of galaxies formed in the early universe, which are too far away to observe in detail.

The team’s work is far from over; ALMA plans to partner with another Chile-based observatory called the Extremely Large Telescope, set to finish construction around 2030, to take more probing images. “In many ways, this is just the beginning,” said Ashley Barnes, a member of the recent image team, in a statement.

Et Cetera

NIH chief on his double duty at CDC

National Institutes of Health (NIH) director Jay Bhattachara explained his plans for his new double duty position heading the Centers for Disease Control and Prevention (CDC)—and rebutted sharp criticisms of his leadership at NIH in a hard-hitting, candid, at times testy 1-hour podcast last week. Bhattacharya told interviewers with Why Should I Trust You that NIH is now “stable” and although his leadership of CDC, where he spent the past week, “won’t be permanent,” he expects to go to Atlanta “every week” for “the next few months” so he can “get it spruced up” for a new leader. As for his moves at NIH, he defended freezes on grants to universities that he described as “racist” and cuts to what he called “politicalized” grants touching on diversity, equity, and inclusion. “We have shifted our priorities,” he said.

Listen to the PODCAST

Artificial IQ

AIs are getting smarter every day. But can they get smart enough to be scientists? “Models have all this knowledge,” one computer scientist noted. But “do they know how to use it?” Truth is, no one is quite sure; although several artificial intelligence tests have been proposed, a given model’s scores aren’t consistent across tests.