People Leo XIV on Saturday announced the appointment of the Vatican’s new ambassador, Apostolic Nuncio, to the U.S. to help manage strained relations with the Trump administration.

Italian Archbishop Gabriele Caccia, 68, a veteran Vatican diplomat who is currently ambassador to the United Nations, previously served as ambassador to the Philippines and Lebanon.

Caccia is replacing 80-year-old Cardinal Christophe Pierre, who is retiring.

«I receive this mission with both joy and a sense of trepidation,» Caccia said after the appointment, according to the Vatican News. He added that his mission was «at the service of communion and peace,» remembering that 2026 marks the 250th anniversary of the U.S.

The pope and President Donald Trump have been at odds over key issues for the White House, including immigration and the war in Iran.

Pierre’s ambassadorship was also at times at odds with the more conservative U.S. Conference of Catholic Bishops while representing Pope Francis’ more progressive priorities.

«Stability and peace are not built with mutual threats, nor with weapons, which sow destruction, pain, and death, but only through a reasonable, authentic, and responsible dialogue,» the American-born pope said on Sunday after the U.S. and Israel launched coordinated strikes on Iran, according to the outlet Chicago Catholic.

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«Faced with the possibility of a tragedy of enormous proportions, I address to the parties involved a heartfelt appeal to assume the moral responsibility to stop the spiral of violence before it becomes an irreparable abyss,» he added.

In early January, Leo also delivered a major policy speech, mostly in English, that came on the heels of the U.S. military action in Venezuela.

Archbishop Gabriele Caccia has been appointed by the pope as the new Vatican ambassador to the U.S.  (Lev Radin/Pacific Press/LightRocket via Getty Images)

«War is back in vogue and a zeal for war is spreading,» the pope warned in the speech.

Trump called it a «great honor for our country» when Leo was elected pope last May after Pope Francis’ death, and when asked about Leo’s remarks earlier this year seemingly pressing him on policy, Trump told Politico he hadn’t seen the statements from the pontiff, but «I’m sure he’s a lovely man.»

He also said that he had met with the pope’s brother, who he called «serious MAGA.»

Last fall, the pope suggested that supporting the «inhuman treatment of immigrants in the United States» is not «pro-life,» leaving White House press secretary Karoline Leavitt to «reject there was inhumane treatment of illegal immigrants in the United States under this administration.»

The pope and the Trump administration have been at odds over immigration and U.S. military actions. (Rocco Spaziani/Archivio Rocco Spaziani/Mondadori Portfolio via Getty Images)

Leavitt, who is Catholic, added that the administration always tries to be as humane as possible while enforcing laws.

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Archbishop Paul S. Coakley, current president of the U.S. conference, said after Caccia’s appointment: «On behalf of my brother bishops, I wish to extend our warmest welcome and our prayerful support to him as he carries out his responsibilities across the United States.»

Trump won 59% of the Catholic vote in the 2024 election, according to Politico.

The Associated Press contributed to this report.

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During the Shield of the Americas summit in Florida on Saturday, outgoing Department of Homeland Security (DHS) Secretary Kristi Noem thanked President Donald Trump for appointing her to a newly created role after she was ousted from overseeing the agency.

Noem, who is moving to the newly created position of special envoy for the Shield of the Americas, showed no ill feelings toward the president and said she was proud of her work at DHS, arguing the department had secured the border and eliminated public safety threats.

«I do want to thank the president for creating this and for giving me the honor and the opportunity to serve as a special envoy to this region, to the Western Hemisphere,» Noem said during the summit at Trump National Doral outside Miami. 

«This Shield of the Americas will be a powerful example to the rest of the world about what’s possible.»

Trump announced this week that Noem would shift into the new role after cutting short her tenure at DHS. 

Noem was removed as the nation’s immigration chief after a turbulent stretch marked by internal clashes and two contentious congressional hearings where even some Republicans pressed her over leadership missteps, including the ad campaign, which she claimed the president had signed off on.

Noem framed the initiative as an effort to expand border security cooperation beyond the United States.

«The way that we cooperate on our shared ideals of freedom and of democracy and safety and security will be a shining light to all of those who wish to be more like all of us,» she said.

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Trump removed Noem as the nation’s DHS chief this week after a turbulent stretch. (Julia Demaree Nikhinson/AP Photo)

Noem, who previously served in Congress and as South Dakota governor before leading DHS, defended her record overseeing immigration enforcement during the past year.

«In the last year, as secretary of Homeland Security, we have focused on securing our border,» she said. «We have transformed our country from one that was being invaded by enemies, millions of them that were coming in unvetted, that we didn’t know who was there and who wished to harm us.»

«We’ve secured that border,» she continued. «We’ve focused on removing public safety threats, and over 3 million people have been deported or removed from our country in the last year.»

Noem argued that stronger border enforcement has allowed the administration to pivot toward economic and diplomatic engagement with neighboring nations.

DHS Secretary Kristi Noem testifies before the Senate Judiciary Committee on Capitol Hill. (Graeme Sloan/Getty Images)

«Secure borders has changed everything for our country,» she said. «Now that America is secure and our borders are secure, we want to focus on our neighbors and to help our neighbors with their borders and challenges that they have so that they may have the security that we enjoy.»

Trump announced on Truth Social that Sen. Markwayne Mullin, R-Okla., will replace her effective March 31, while Noem shifts to the newly created envoy role.

Members of Trump’s Cabinet, including Secretary of State Marco Rubio, Secretary of War Pete Hegseth, Secretary of Commerce Howard Lutnick and United States Trade Representative Jamieson Greer attended Saturday’s summit. 

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Leaders from other nations included Argentina’s Javier Milei, El Salvador’s Nayib Bukele Ortez, Bolivia’s Rodrigo Paz Pereira, Costa Rica’s Rodrigo Chaves Robles, Panama’s José Raúl Mulino Quintero, and Trinidad and Tobago’s Kamla Persad-Bissessar, Chile’s Jose Antonio Kast, the Dominican Republic’s Luis Rodolfo Abinader Corona, Ecuador’s Daniel Roy Gilchrist Noboa Azín, Guyana’s Mohamed Irfaan Ali, Honduras’ Nasry «Tito» Asfura and Paraguay’s Santiago Peña.

Notably missing were the leaders of Venezuela, Delcy Rodríguez, and Mexico, Claudia Sheinbaum Pardo.

Fox News Digital’s Alec Schemmel contributed to this report.

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El avance científico reciente ha evidenciado que la vida en Marte podría ser posible bajo ciertas condiciones experimentales. Un equipo internacional demostró que algunos microorganismos sobreviven y se replican en suelos que simulan las condiciones extremas del planeta rojo, ampliando así los límites conocidos para la habitabilidad extraterrestre.

¿Es factible cultivar vida en Marte usando suelos que imitan las características del planeta rojo? Los experimentos actuales confirman que determinados microorganismos logran sobrevivir y multiplicarse con niveles de sequedad y baja disponibilidad de agua similares a los encontrados en Marte, aunque el cultivo de plantas requiere estrategias especiales, como el aporte de nutrientes específicos o la integración de organismos simbióticos.

Investigadores de la Universidad de Aberdeen y el Centro de Astrobiología de España, liderados por Jyothi Basapathi Raghavendra, Maria-Paz Zorzano y Javier Martin-Torres, realizaron un estudio donde demostraron que bacterias obtenidas de ambientes desérticos consiguieron replicarse y aumentar su ADN en simuladores de regolito marciano. Esta replicación microbiana se registró con actividades de agua tan bajas como 0,34, un valor mínimo que hasta ahora se consideraba inviable según el umbral aceptado de 0,585.

La actividad de agua, clave en estos experimentos, señala cuánta agua libre hay disponible en el suelo para el desarrollo microbiano. El equipo empleó suelos basálticos enriquecidos con yeso y sales, emulando el regolito marciano, y utilizó la cuantificación de ADN para constatar el crecimiento bacteriano, incluso en condiciones de gran aridez.

Los científicos sometieron los suelos simulados a distintos niveles de humedad bajo temperatura y presión constantes. El mayor incremento de ADN ocurrió en suelos con más humedad, pero incluso se observó un aumento del material genético tras un mes de incubación.

Al comparar los distintos grupos el día treinta, los resultados arrojaron un valor estadístico confirmando la replicación microbiana bajo estas condiciones extremas. La validación microscópica y molecular evitó la presencia de procesos no replicativos, reforzando que las células bacterianas estaban activas.

El papel de las sales hidratables también se puso a prueba: al añadir 5% de sulfato de magnesio al suelo, se consiguió que el regolito retuviera el doble de agua que el estándar, aunque el desarrollo bacteriano resultó ser más lento. El máximo registrado fue de 3,2 nanogramos de ADN, frente a los 5-6 ng de otros escenarios.

Estos hallazgos amplían el margen para la existencia de la vida en ambientes secos y suponen nuevos retos para la exploración espacial. El estudio cuestiona los límites impuestos por el comité COSPAR respecto a las “Regiones Especiales” de Marte, definidos hasta ahora por actividades de agua superiores a 0,5.

Los autores del experimento proponen revisar esos límites legales, ya que algunos microorganismos pueden replicarse con menos humedad de la considerada anteriormente, lo que incrementa los riesgos de contaminación biológica en futuras misiones y refuerza la necesidad de mejores protocolos de esterilización.

Sin embargo, advierten que el experimento se realizó bajo presión y atmósfera terrestre. Replicar los resultados en ambientes con dióxido de carbono y baja presión—más parecidos a Marte—exigirá nuevas pruebas para aproximarse a la realidad marciana.

Paralelamente, la investigación dirigida por Jessica Atkin examinó el cultivo de garbanzo (Cicer arietinum) en simuladores de suelo lunar. Según los expertos, ningún vegetal produjo semillas sin la adición conjunta de compost de lombriz y hongos micorrícicos arbusculares; esta combinación permitió que algunas plantas florecieran y produjeran semillas, aunque el rendimiento se mantuvo bajo en comparación con suelos agrícolas comerciales.

El análisis señala que el suelo lunar simulado contiene metales como aluminio y zinc, e impide una adecuada filtración de agua.

No obstante, la mezcla de compost y hongos simbióticos mejoró tanto la circulación de nutrientes como la masa seca de raíz y tallo, logrando que el peso promedio de semillas fuera comparable al de plantas cultivadas en tierra común cuando se empleó entre 25% y 50% de compost.

Todas las plantas cultivadas en suelo lunar simulado mostraron signos de estrés, como hojas amarillas y crecimiento restringido, lo que pone de manifiesto la necesidad de nuevas estrategias de bioremediación y microbiomas adaptados para el desarrollo agrícola fuera de la Tierra.

Los resultados de ambas líneas de investigación subrayan que aún no se han reproducido perfectamente las condiciones reales de Marte o la Luna, por lo que extrapolar estos datos a escenarios de colonización espacial requiere cautela y más estudios.

La capacidad de ciertos microorganismos de multiplicarse en regolito marciano simulado—incluso bajo extrema sequedad y sin fuentes externas de carbono—sugiere que la vida puede persistir en entornos que hasta ahora se consideraban incompatibles, marcando un nuevo umbral para la resiliencia biológica fuera de la Tierra.