Earth-Like Planets Are More Common Than We Thought, Study Says
Welcome back to the Abstract! These are the studies this week that got hosed with star spray, mounted a failed invasion, declined to comment, and achieved previously unknown levels of adorability.
First, a study about how the solar system wasn’t destroyed 4.5 billion years ago (phew!). Then: a human touch on an ancient boat, the duality of posters and lurkers, and an important update on toadlets.
As always, for more of my work, check out my book First Contact: The Story of Our Obsession with Aliensor subscribe to my personal newsletter the BeX Files.
Sink into a warm cosmic-ray bath
Earth was cosmically conceived in part by a massive shockwave from a nearby supernova, which seeded our home world and neighboring rocky planets with telltale radioactive signatures, according to a new study.
The solar system’s rocky planets contain short-lived radionuclides (SLRs), which are ancient elements that were likely barfed out from exploding stars. For this reason, scientists have long suspected that stars must’ve detonated next to the gassy disk that gave rise to the solar system. The heat generated from these radioactive elements helped the building blocks of the rocky planets—Mercury, Venus, Earth, and Mars—melt together so they could become whole worlds, which means we owe our existence to these ancient supernovas.
Now, a team has developed a new model to explain how the primordial pyrotechnics didn’t just blow up the nascent solar system. The results suggest that rocky Earth-like worlds may be common in the universe, with potential implications for the search for extraterrestrial life.
“A key question in astronomy is how ubiquitous Earth-like rocky planets are,” said researchers led by Ryo Sawada of the University of Tokyo. “The formation of terrestrial planets in our Solar System was strongly influenced by the radioactive decay heat of SLRs, particularly aluminum-26, likely delivered from nearby supernovae.”
“However, the supernova injection scenario faces an unresolved problem in that existing supernova models could not reproduce both the relative and absolute abundances of SLRs without disrupting the protosolar disk,” an event that “would likely prevent the Solar System formation altogether,” the team added.
In other words, it’s hard to explain how the solar system got its high abundance of SLRs without killing it in the cradle. Sawada and his colleagues propose a solution that involves at least one star exploding about three light years of the disk, sparking a shockwave that created a cosmic-ray “bath.”
In this “immersion mechanism,” energetic cosmic rays trapped in the bath triggered SLR-producing reactions directly within the disk. This contrasts with the hypothesis that the SLRs were largely injected and then mixed up in the disk through some unknown process. This new solution can account both for the high abundance of certain SLRs, like aluminum-26, and the fact that the solar system was not destroyed, as evidenced by its apparent continued existence.
“Our results suggest that Earth-like, water-poor rocky planets may be more prevalent in the
Galaxy than previously thought,” the team said, noting that many disks are rocked by similar supernova-shockwaves. “This challenges previous interpretations that classified the Solar System as an outlier with a particularly high [aluminum-26] abundance.”
In addition to offering a new hypothesis for an old astronomical problem, the study gets bonus points for its extremely poetic title: “Cosmic-ray bath in a past supernova gives birth to Earth-like planets.” If you say this enchanted phrase three times, somewhere an Earth-like world will be born.
In other news…
The biometrics of a Baltic boatsman
Stars aren’t the only things leaving their dirty fingerprints in unexpected places this week. Archeologists working on the mysterious Hjortspring boat, a 2,400-year-old Scandinavian vessel, discovered a tantalizing partial human fingerprint in its caulking, providing “a direct link to the ancient seafarers who used this boat,” according to the study.
The ridges of the fingerprint “fall within average distributions for both adult male and females as well as for juvenile adults, making it difficult to say much about the individual who produced the print,” said researchers led by Mikael Fauvelle of Lund University. “The most likely interpretation, however, is that it was made during repairs by one of the crew members on the boat itself, providing a direct link to the seafarers of the ancient vessel.”
Regardless of this person’s identity, their voyage didn’t end well. Researchers think the crew of the Hjortspring boat probably sailed from the eastern Baltic Sea to attack the Danish island of Als, where they were defeated. “The victors [deposited] the weapons of their vanquished foes together with one of their boats into the bog,” where they remained for millennia until they were rediscovered in the 1880s, the team said.
It’s a timeless reminder for would-be invaders: Don’t get caulky.
Long-time lurker, first-time poster
At last, scientists have investigated the most elusive online demographic: the humble lurker. A team recruited 520 Redditors in the U.S. to participate in small subreddits focused on a variety of political topics during the summer of 2024. The aim was to probe why some people became prolific “power-users” that post with voluminous confidence, while others remained wallflowers.
“Online political discussions are often dominated by a small group of active users, while most remain silent,” said researchers led by Lisa Oswalt of the Max Planck Institute for Human Development. “This visibility gap can distort perceptions of public opinion and fuel polarization.”
The team found that “lurking (posting nothing) was most common among users who perceived discussions as toxic, disrespectful, or unconstructive.” Lurkers were offered small payments to post in the experiment, which succeeded in motivating some to contribute to discussions. As a result, the study concluded that “future interventions may be able to make online political discussions more representative by offering more positive social rewards for lurkers to post.”
At last, an opportunity to unionize the lurkers of the world. Solidarity (in silence) forever.
It’s the great pumpkin toadlet, Charlie Brown
We will close, as we have before, with an impossibly cute toadlet. Scientists have discovered this new species of “pumpkin toadlet” in the “cloud forests” of Brazil, a sentence so twee that it’s practically its own fairy tale. The tiny toad Brachycephalus lulai, pictured below on a pencil tip, belongs to a family of “flea toads” that are among the smallest vertebrates on Earth.
“Our team sought to better document the individual variation of all Brachycephalus species in southern Brazil, looking for them in the field over the past seven years,” said researchers led by Marcos R. Bornschein of São Paulo State University. “As a result of this work, we discovered and herein described a population collected on the eastern slope of Serra do Quiriri as a new species.”
The team also reported that the toads are actively colonizing newly formed cloud forests, which are high-altitude woods shrouded in mist. The researchers propose making these unique habitats into refuges for the adorable anurans.
Thanks for reading! See you next week.
New investigations of the Hjortspring boat: Dating and analysis of the cordage and caulking materials used in a pre-Roman iron age plank boat
The Hjortspring boat is the only intact example of a prehistoric sewn plank boat ever found in Scandinavia.journals.plos.org
A Fundamental ‘Constant’ of the Universe May Not Be Constant At All, Study Finds
Welcome back to the Abstract! Here are the studies this week that took a bite out of life, appealed to the death drive, gave a yellow light to the universe, and produced hitherto unknown levels of cute.First, it’s the most epic ocean battle: orcas versus sharks (pro tip: you don’t want to be sharks). Then, a scientific approach to apocalyptic ideation; curbing cosmic enthusiasm; and last, the wonderful world of tadpole-less toads.
As always, for more of my work, check out my book First Contact: The Story of Our Obsession with Aliens, or subscribe to my personal newsletter the BeX Files.
Now, to the feast!
I guess that’s why they call them killer whales
Orcas kill young great white sharks by flipping them upside down and tearing their livers out of their bellies, which they then eat family-style, according to a new study that includes new footage of these Promethean interactions in Mexican waters.
“Here we document novel repeated predations by killer whales on juvenile white sharks in the Gulf of California,” said researchers led by Jesús Erick Higuera Rivas of the non-profit Pelagic Protection and Conservation AC.
“Aerial videos indicate consistency in killer whales’ repeated assaults and strikes on the sharks,” the team added. “Once extirpated from the prey body, the target organ is shared between the members of the pods including calves.”
Sequence of the killer whales attacking the first juvenile white sharks (Carcharodon carcharias) on 15th of August 2020. In (d) The partially exposed liver is seen on the right side of the second shark attacked. Photos credit: Jesús Erick Higuera Rivas.
I’ll give you a beat to let that sink in, like orca teeth on the belly of a shark. While it's well-established that orcas are the only known predator of great white sharks aside from humans, the new study is only the second glimpse of killer whales targeting juvenile sharks.
This group of orcas, known as Moctezuma’s pod, has developed an effective strategy of working together to flip the sharks over, which interrupts the sharks’ sensory system and puts them into a state called tonic immobility. The authors describe the pod’s work as methodical and well coordinated.
“Our evidence undoubtedly shows consistency in the repeated assaults and strikes, indicating efficient maneuvering ability by the killer whales in attempting to turn the shark upside down, likely to induce tonic immobility and allow uninterrupted access to the organs for consumption, " the team said. Previous reports suggest that “the lack of bite marks or injuries anywhere other than the pectoral fins shows a novel and specialized technique of accessing the liver of the shark with minimal handling of each individual.”
An orca attacking a juvenile great white shark. Image: Marco VillegasSharks, by the way, do not attack orcas. Just the opposite. As you can imagine based on the horrors you have just read, sharks are so petrified of killer whales that they book it whenever they sense a nearby pod.
“Adult white sharks exhibit a memory and previous knowledge about killer whales, which enables them to activate an avoidance mechanism through behavioral risk effects; a ‘fear’- induced mass exodus from aggregations sites,” the team said. “This response may preclude repeated successful predation on adult white sharks by killer whales.”
In other words, if you’re a shark, one encounter with orcas is enough to make you watch your dorsal side for life—assuming you were lucky enough to escape with it.
In other news…
Apocalypse now plz
You may have seen the doomer humor meme to “send the asteroid already,” a plea for sweet cosmic relief that fits our beleaguered times. As it turns out, some scientists engage in this type of apocalyptic wish fulfillment professionally.
Planetary defense experts often participate in drills involving fictional hazardous asteroids, such as the 2024PDC25, a virtual object “discovered” at the 2025 Planetary Defense Conference. In that simulation, 2024PDC25 had a possible impact date in 2041.
Now a team has used that exercise as a jumping off point to explore what might happen if it hit even earlier, channeling that “send the asteroid already” energy.. The researchers used this time-crunched scenario to speculate about the effect on geopolitics and pivotal events, such as the 2028 US Presidential elections.
“As it is very difficult to extrapolate from 2025 across 16 years in this ‘what-if’ exercise, we decided to bring the scenario forward to 2031 and examine it with today’s global background,” Rudolf Albrecht of the Austrian Space Forum. “Today would be T-6 years and the threat is becoming immediate.”
As the astro-doomers would say: Finally some good news.
Big dark energy
First, we discovered the universe was expanding. Then, we discovered it was expanding at an accelerating rate. Now, a new study suggests that this acceleration might be slowing down. Universe, make up your mind!
But seriously, the possibility that the rate of cosmic expansion is slowing is a big deal, because dark energy—the term for whatever is making the universe expand—was assumed to be a constant for decades. But this consensus has been challenged by observations from the Dark Energy Spectroscopic Instrument (DESI) in Arizona, which became operational in 2021. In its first surveys, DESI’s observations have pointed to an expansion rate that is not fixed, but in flux.
Together with past results, the study “suggests that dark energy may no longer be a cosmological constant” and “our analysis raises the possibility that the present universe is no longer in a state of accelerated expansion,” said researchers led by Junhyuk Son of Yonsei University. “This provides a fundamentally new perspective that challenges the two central pillars of the [cold dark matter] standard cosmological model proposed 27 years ago.”
It will take more research to constrain this mystery, but for now it’s a reminder that the universe loves to surprise.
And the award for most squee goes to…
We’ll end, as all things should, with toadlets. Most frogs and toads reproduce by laying eggs that hatch into tadpoles, but scientists have discovered three new species of toad in Tanzania that give birth to live young—a very rare adaptation for any amphibian, known as ovoviviparity. The scientific term for these youngsters is in fact “toadlet.” Gods be good.
“We describe three new species from the Nectophrynoides viviparus species complex, covering the southern Eastern Arc Mountains populations,” said researchers led by Christian Thrane of the University of Copenhagen. One of the new species included “the observation of toadlets, suggesting that this species is ovoviviparous.”
One of the newly described toad species, Nectophrynoides luhomeroensis. Image: John Lyarkurwa.
Note to Nintendo: please make a very tiny Toadlet into a Mario Kart racer.
Thanks for reading! See you next week.
Museomics and integrative taxonomy reveal three new species of glandular viviparous tree toads (Nectophrynoides) in Tanzania’s Eastern Arc Mountains (Anura: Bufonidae)
Abstract For the last century, herpetologists have referred to any Nectophrynoides Noble, 1926 toad characterized by a large, robust body, with large, distinct parotoid glands, as Nectophrynoides viviparus (Tornier, 1905).Christian Thrane (Senckenberg Gesellschaft für Naturforschung)
