Une nouvelle offensive du groupe armé M23 fait craindre à l’ONU un «embrasement régional».

Due to the lack of electricity supply, drinking water is being transported to Odesa from seven regions.

A passenger train traveling from Bucharest to Kyiv was stopped while leaving Moldova at the Valcinet border crossing after a report of a suspected bomb.

Les négociations de paix en Ukraine se poursuivent. Mais derrière les discussions des émissaires américains, se cacheraient-ils des accords commerciaux ?

Nigeria's biggest city is known for its vibrant arts scene, nightlife and creativity, but street art is relatively unknown.

About one hundred civilians, including five Ukrainians, who were held in Belarus, have been released.

During Russia's December 13 attack, the Zaporizhzhia Nuclear Power Plant was disconnected from Ukraine's power grid for more than an hour due to damage to power transmission lines.

The northern part of Pokrovsk in the Donetsk region remains under the control of the Ukrainian Defense Forces.

Le comédien Bruno Solo, passionné d'histoire, est l'invité d'Isabelle Layer dans l'interview culture de franceinfo, samedi 13 décembre.

Nigeria's biggest city is known for its vibrant arts scene, nightlife and creativity, but street art is relatively unknown.

L'état de santé du jeune joueur vedette sera réévalué lundi, selon son entraîneur.

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 Aliens or subscribe to my personal newsletter the BeX Files. 

Sink into a warm cosmic-ray bath

Sawada, Ryo et al. “Cosmic-ray bath in a past supernova gives birth to Earth-like planets.” Science Advances.

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

Fauvelle, Mikael et al. “New investigations of the Hjortspring boat: Dating and analysis of the cordage and caulking materials used in a pre-Roman iron age plank boat.” PLOS One

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

Oswald, Lisa et al. “Disentangling participation in online political discussions with a collective field experiment.” Science Advances.

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 

Bornschein, Marcos R. et al. “A new species of Brachycephalus (Anura: Brachycephalidae) from Serra do Quiriri, northeastern Santa Catarina state, southern Brazil, with a review of the diagnosis among species of the B. pernix group and proposed conservation measures.” PLOS One.

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.

The release of the prisoners, including a Nobel laureate and an opposition leader, was part of a monthslong rapprochement between Washington and Minsk.

© Coordination Headquarters for the Treatment of Prisoners of War

Injuries were reported in an assault near the ancient city of Palmyra, the Syrian government’s news agency said.

© Baderkhan Ahmad/Associated Press

She was one of the Clinton 12, Black students who broke a race barrier by entering a Tennessee high school in 1956 in the face of harassment by white segregationists.

© Don Cravens/Getty Images

Opposition activist Maria Kolesnikova is among those released in exchange for a deal with the US.

Warehouses supplying the vast majority of Ukraine's pharmacies have been destroyed over recent months.

Le chanteur a offert vendredi au Centre Bell un concert chaleureux où le konpa haïtien rencontrait le R&B et l’afropop.

C'est ce qu'a annoncé, samedi, l'ONG de défense des droits humains Viasna, après des pourparlers entre Minsk et Washington.

L'armée ukrainienne ne communique pas de chiffre officiel mais des dizaines de milliers de soldats sont susceptibles de souffrir d'un stress post-traumatique. Pour leur offrir un moment de répit, des séances d'hippothérapie sont organisées.

Opposition activist Maria Kolesnikova is among those released in exchange for a deal with the US.

Warehouses supplying the vast majority of Ukraine's pharmacies have been destroyed over recent months.

La première étape de la saison de snowboard cross a été remportée par le Français Jonas Chollet.

Des experts américains ont récemment fait reculer de façon importante la vaccination contre l'hépatite B.

Protests and attacks have marked a backlash at resettlement centers in Ireland and have spread to neighborhoods where even longtime immigrants feel unsafe.

More than one million consumers have been left without electricity as a result of an overnight Russian attack, and repair work has already begun.

Ces libérations ont lieu après des pourparlers entre Minsk et Washington.

L'Américaine confirme son retour au sommet en super-G à deux mois des Jeux olympiques.

Much of Ukraine’s largest Black Sea port was without power, heat and water on Saturday after strikes from Russia, which has shown little appetite for a deal to end the war.

© Nina Liashonok/Reuters

Newly appointed Czech Prime Minister Andrej Babis has said he is not ready to finance Ukraine at the expense of Czech citizens.

Finnish President Alexander Stubb has canceled his plans to visit the United States on Monday and Tuesday and will instead travel to Germany, where he will participate in discussions on Ukraine.

Les eaux qui ont envahi Abbotsford, en Colombie-Britannique, cette semaine sont en train de se retirer, mais Environnement Canada prévient que d’autres précipitations sont attendues dans la vallée du Fraser, déjà saturée.

Direction l'Allemagne à la découverte de l'un des marchés de Noël les plus beaux et réputés du pays. Digne d'un conte de fées, il est situé au cœur de la Forêt-Noire et les places y sont chères.

La guerre en Ukraine, déclenchée en février 2022, avait conduit l'Europe à prendre des sanctions contre la Russie, comme la mise en place d'un embargo sur le pétrole. Contourné, il aurait permis à la Russie de continuer à s'enrichir pour financer le conflit.

Comme chaque soir, le JT du 23h fait un tour de l'actualité diffusée par les chaînes européennes de télévision. C'est l'Eurozapping du vendredi 12 décembre.  

Russia plans to increase the serial production of the Oreshnik intermediate-range ballistic missile and is considering options for its modernization to enhance the destructive potential of its warhead.

Air Defense Forces destroyed 417 Russian drones, four Iskander-K cruise missiles, and nine Kalibr missiles.

Le roi Charles III, qui avait annoncé il y a près de deux ans qu'il était atteint d'un cancer, va mieux. Son traitement sera bientôt allégé. Le souverain a délivré un message de prévention en incitant les Britanniques à se faire dépister.

Persécutés durant la période soviétique, les cosaques de Russie ont épousé le tournant autoritaire et impérialiste pris par le Kremlin au long du XXIe siècle. Maintien de l’ordre, encadrement de la jeunesse et déploiement sur les champs de bataille d’Ukraine, ils sont désormais de précieux auxiliaires de la politique de Vladimir Poutine.

Chaque semaine, Judith Grimaldi reçoit un invité dans son podcast "Avec Judith". Cette fois, c'est Benjamin Stora. L'historien a grandi dans une famille juive d'Algérie, qu'il a dû quitter pendant la guerre. À notre micro, il revient sur ce départ qui a marqué ses jeunes années. L'émission intégrale est à retrouver dès ce samedi midi sur la chaîne YouTube de France 24.

Malgré la situation sécuritaire très précaire en Libye, le musée national du pays a rouvert ses portes en grandes pompes après 14 ans de fermeture.

Une semaine après avoir critiqué publiquement son club et son entraîneur Arne Slot, Mohamed Salah devrait réintégrer le groupe de Liverpool, selon la presse britannique. L'Égyptien avait été écarté de l'équipe pour le match de Ligue des champions contre l'Inter mercredi, mais pourrait rejouer pour les Reds contre Brighton samedi.

La France s'apprête à vacciner près d’un million de bovins contre la dermatose nodulaire contagieuse, a annoncé samedi la ministre de l'Agriculture. Parallèlement, les éleveurs multiplient les actions de protestation à travers le pays contre l'abattage de troupeaux.

Dans la ville de Bethléem, en Cisjordanie occupée, on se prépare à célébrer les fêtes de Noël, ce qui n'était plus le cas depuis le début de la guerre à Gaza. Les pèlerins se font cependant rares. Un sujet de nos confrères de France 2.

Elon Musk envisage d'introduire SpaceX en Bourse, une opération qui pourrait devenir la plus importante entrée de l'histoire sur les marchés. L'entreprise, dont les revenus explosent grâce à sa constellation internet Starlink, viserait une valorisation colossale d'environ 1 500 milliards de dollars. Une manœuvre qui fascine et interroge.

Donald Trump envoie son émissaire Steve Witkoff à Berlin ce week-end pour rencontrer Volodymyr Zelensky et des dirigeants européens, au moment où les Etats-Unis poussent l'Ukraine à des concessions majeures pour mettre fin à la guerre avec la Russie. Les précisions de Gulliver Cragg, correspondant de France 24 à Kiev.

La Russie a dit samedi avoir frappé des installations industrielles et énergétiques ukrainiennes dans la nuit avec des missiles hypersoniques, dans ce qu'elle a qualifié de représailles à des frappes ukrainiennes contre des "cibles civiles". De son côté, le président américain Donald Trump envoie son émissaire Steve Witkoff à Berlin ce week-end pour rencontrer Volodymyr Zelensky et des dirigeants européens. Suivez en direct les développements de la guerre en Ukraine.

La Thaïlande et le Cambodge se sont de nouveau accusés samedi matin de poursuivre les combats le long de leur frontière commune, quelques heures après que le président américain Donald Trump a annoncé un cessez-le-feu entre les deux belligérants. Les précisions de Valentin Cebron, correspondant RFI et La Croix en Thaïlande.