The Case for Life on Saturn’s Moon Gets a Boost

Welcome back to the Abstract! Here are the studies this week that defied death, cooked out, bulked up, and capped it off with an extraterrestrial spit-take.

First, prehistoric peoples risked their lives to make art—and it was totally worth it. Then, what’s the best cut of a two-ton armadillo? Next, a funerary procession for a whale, a glow-up for a rogue planet, and a swim in an alien ocean.

Finally, I am so excited that my book First Contact: The Story of Our Obsession with Aliens is now officially out! If you are curious about aliens of the Hellenistic world, centuries-old UFO sightings, a guide to the most promising systems for alien life, and the creepiest solutions to the Fermi Paradox (and more), this book is for you. 

This rock art rocks

Guagnin, Maria et al. “Monumental rock art illustrates that humans thrived in the Arabian Desert during the Pleistocene-Holocene transition.” Nature Communications.

Some 12,000 years ago, a group of desert artists tiptoed out onto dangerous cliff ledges to engrave the rock with enchanting depictions of camels, gazelles, ibex, wild horses, and other animals living in the shifting sands around them. One wrong step could have led to their deaths, but the artists persisted in an act of creative courage.

Now, archaeologists have discovered the monumental rock art left by this bygone culture in the Nafud desert of northern Saudi Arabia. One particularly dramatic scene was engraved from a tiny sloped ledge 12 storeys off the ground, and depicts 23 life-sized camels and horses in a line that stretches horizontally across 75 feet.

Rock art panels at Jebel Arnaan. Image: Maria Guagnin

“Some of these panels were etched onto cliff surfaces in inaccessible but highly visible locations,” said researchers led by Maria Gaugnin of the Max Planck Institute of Geoanthropology. “The difficulty in getting to and engraving these rock surfaces, and their enhanced visibility by height, were clearly attractive for the engravers.” 

Though archeologists typically distinguish between rock art and modern graffiti as distinct traditions, there may be overlaps in their intent and execution—including, in this case,  possible attraction to the challenges of accessing a dangerous site.  

“The precarious nature of the engraving process is particularly evident in the largest recorded panel,” the team said, referring to the 75-footer described above. “This panel would have been accessed by climbing up a cliff and then engraved while standing on a downward sloping ledge, only ~30-50 centimeters in width,” which is roughly a foot across.

“Today the sandstone is too degraded to reach the ledge safely, and the panel was documented using a drone,” they added.” The friable nature of the substrate and the slope of the narrow ledges suggest the engravers likely risked their lives to create this art.” 

The rock ledge where the main panel was engraved. Image: Monumental rock art panel at Jebel Misma (JMI18)

Talk about commitment to the craft. Given the high stakes and the spectacular scale of the panels, this art must have been a cherished touchstone to these early desert peoples. During the ice age, this region was extremely arid and virtually impenetrable, but as the glacial cover receded, oases and other pockets of habitability had opened up to nomads. 

The rock art proves that these wanderers were not only navigating the terrain, but imprinting their culture and worldview onto it. For countless generations, these grand visions welcomed peoples passing through the desert, serving as a landmark and a cultural heirloom, before they faded into obscurity.

“Freshly engraved against the varnish, the images would have had considerable visual impact,” the team concluded. “The engravings, which may have been created over a time span of millennia, would have reminded people of ancient symbolisms and beliefs of their group, which likely structured their highly seasonal lives and thus enhanced their ability to thrive in these marginal landscapes.”

In other news…

I’m so hungry, I could eat a giant ground sloth

Prates, Luciano et al. Extinct megafauna dominated human subsistence in Southern South America before 11,600 years ago. Science Advances.

At the same time that the desert artists were engraving cliff walls, people in South America were devouring giant sloths, giant armadillos, mastodons, and other megafauna that have since gone extinct—potentially because they were so tasty. 

That’s the upshot of a new study of archaeological sites in Argentina and Chile that date back some 12,000 years to the late Pleistocene period. The results revealed a preference for mega-big game—like beefy ground sloths and car-sized armadillos—bolstering the case that humans may have played a significant role in their extinction. 

Megafaunal species were preferred prey for humans in Southern South America. Image: Luciano Prates et al. Megafaunal reconstructions in the figure were provided and authorized by Megafauna 3D Project (https://www.megafauna3d.org)

“The late Pleistocene extinction of terrestrial megafauna… is one of the most spectacular changes in American mammal history, and its cause is one of the most hotly debated issues in archaeology and paleoecology,” said researchers led by Luciano Prates of Universidad Nacional de la Plata. 

“Here, we have shown… that extinct megafauna—at the apex of the prey ranking—were the main prey of early foragers, particularly in regions with high abundance and diversity, such as the Pampas, Patagonia, and central Chile,” the team concluded.

While climate and other factors certainly played a role in these extinctions, there may well be a more obvious culprit [looks at humanity; humanity belches; the belch smells like Pleistocene megafauna].

The world’s saddest version of “Baby Beluga”

Hudson, Justine M. and Watt, Cortney A. “Beluga Whale (Delphinapterus leucas) Behavior Towards a Dead Conspecific.” Marine Mammal Science.

“How do animals react to dead or dying conspecifics? Do they comprehend death? Do they grieve? These are the fundamental questions asked in the field of comparative thanatology, which focuses on how animals respond to death.” 

Phew, what a heavy lead-in to a study. Nonetheless, a team has now explored these questions with drone observations of beluga whales responding to a dead beluga calf in Hudson Bay near Churchill, Manitoba. The baby may have been a stillborn or perhaps died shortly after birth, as there were no signs of trauma on its body.

Drone footage of the calf. Image: Hudson, Justine M. and Watt, Cortney A. 

“We documented 15 instances where belugas from outside of the video frame swam directly towards the dead calf, including 4 mother-calf pairs and 11 individuals,” said Justine Hudson and Cortney Watt of Fisheries and Oceans Canada. “The dead calf was surrounded by free-swimming belugas for the entire duration of the video.”

“The dead calf and surrounding belugas were recorded for ~4 min and 17 s before the depleted drone battery required us to land, and we were unable to relocate the calf after changing the batteries,” they added.

Even the battery was too bummed out to endure. But while loss of life is sad, it’s all in a day’s work for a comparative thanatologist.

Rogue planets grow up so fast

Almendros-Abad, Victor et al. “Discovery of an Accretion Burst in a Free-floating Planetary-mass Object.” The Astrophysical Journal Letters.

The record for most epic bulk-up has been broken by a rogue planet that is gaining an astonishing six billion tonnes of mass per second—an unprecedented rate of swole. The planet, named Cha 1107-7626, is about five to 10 times as massive as Jupiter and does not orbit any star. And why should it? Who needs a star when you’re radiant all by yourself?

Indeed, scientists discovered the world thanks to the light generated by its record growth-spurt, which peaked for at least two months this summer and was still glowing strong when observations stopped in August 2025, showing “the strongest accretion rates measured” in a planet, according to the study.  

Artist concept of Cha 1107-7626. Image: ESO/L. Calçada/M. Kornmesser

“These kinds of accretion bursts are key events in the early evolution of stars,” said researchers led by Victor Almendros-Abad of the Astronomical Observatory of Palermo, National Institute for Astrophysics (INAF), Italy. “Our target is the lowest mass object observed thus far that is going through an accretion burst” and provides “a glimpse into the nature of accretion in planetary-mass objects.”

A sneak peek of an alien ocean

Khawaja, Nozair et al. “Detection of organic compounds in freshly ejected ice grains from Enceladus’s ocean.” Nature Astronomy.

Shout out to the Enceladus-heads: Scientists have discovered new chemicals in the sea spray of this Saturnian moon that hint at organic processes and hydrothermal activity within its interior ocean, boosting the case that it may be habitable. 

In 2008, the NASA-ESA Cassini orbiter gulped some alien seawater as it flew through plumes that erupt from Enceladus’s south pole. Now, scientists have reanalyzed data from one particularly speedy run through the moon sprinkler—during which Cassini reached 40,000 miles per hour—exposing “previously unobserved molecular fragments,” according to a study. 

The “freshly ejected” compounds included organic molecules like ethers, ethyls, and partial remnants of what might be larger compounds bearing nitrogen and oxygen, said researchers led by Nozair Khawaja of the University of Berlin. These chemicals hint at “a hydrothermal origin” and “the synthesis and evolution of organics.”  

In other words, Enceladus likely has seafloor environments similar to hydrothermal vent systems on Earth, which are hotspots for life. Whether the moon’s vents also have weird creepy crawlies on them is a question that is keeping many of us up at night, so could someone please just send a scuba team there already?

With that, may you enter your weekend with a spritz of fresh organic moon mist.

Thanks for reading! See you next week.