❌

Normal view

Europa podría carecer de un fondo oceánico activo y eso complica la búsqueda de vida

8 January 2026 at 11:00
Vista artística de Europa, la luna helada de Júpiter, mostrando su superficie agrietada de hielo y el océano subterráneo que podría albergar agua líquida.

Una nueva investigación sugiere que la luna helada de Júpiter no tiene la actividad geológica necesaria en su fondo marino para sostener ecosistemas como los de la Tierra, lo que obliga a replantear cómo y dónde buscar señales de vida más allá de nuestro planeta.

Europa, uno de los satélites más estudiados de Júpiter, ocupa desde hace años un lugar privilegiado en la lista de mundos potencialmente habitables del sistema solar. Bajo una corteza de hielo de varios kilómetros de espesor, los científicos creen que se esconde un océano global de agua líquida, con un volumen comparable o incluso superior al de todos los mares terrestres juntos. La combinación de agua, energía y química ha convertido a este mundo helado en un objetivo prioritario para la astrobiología.

Sin embargo, una nueva investigación publicada en Nature Communications introduce un matiz importante —y poco alentador— en este escenario. Según el estudio, el fondo oceánico de Europa podría ser geológicamente inactivo, incapaz de generar las fracturas y procesos que en la Tierra alimentan algunos de los ecosistemas más antiguos y resistentes del planeta. De confirmarse, esta característica limitaría de forma significativa las fuentes de energía química disponibles para la vida.

El papel clave del fondo oceánico en la Tierra

En nuestro planeta, gran parte de la vida marina profunda no depende del Sol. En lugar de fotosíntesis, numerosos organismos obtienen energía de reacciones químicas que se producen en torno a fuentes hidrotermales del fondo oceánico. Estas chimeneas se forman cuando el agua de mar se filtra por grietas de la corteza terrestre, se calienta al contacto con rocas calientes y emerge cargada de compuestos químicos reducidos.

Este proceso, conocido como serpentinización y otras reacciones agua-roca, libera hidrógeno, metano y minerales que sirven de combustible para comunidades microbianas complejas. Alrededor de estas fuentes prosperan bacterias, arqueas y organismos multicelulares, demostrando que la vida puede florecer incluso en condiciones extremas y sin luz solar.

Durante décadas, los científicos han especulado con la posibilidad de que un proceso similar ocurra en Europa. La presencia de un océano profundo, estimado en unos 97 kilómetros, y el calentamiento interno generado por las fuerzas de marea de Júpiter parecían ingredientes suficientes para sostener actividad geológica en el fondo marino.

Un cálculo detallado de las fuerzas internas

El nuevo estudio se propuso poner a prueba esa suposición con un enfoque cuantitativo. Los investigadores calcularon cuánta tensión mecánica sería necesaria para activar fallas y fracturas en el fondo rocoso de Europa. A continuación, compararon ese umbral con las fuerzas reales que actúan en el interior de la luna.

La principal fuente de energía considerada fue la fuerza de marea ejercida por Júpiter. Europa orbita al gigante gaseoso cada 84 horas, lo que provoca que el satélite se estire y se comprima de forma rítmica. Este efecto es responsable, por ejemplo, de la intensa actividad volcánica de Ío, otra luna joviana. En el caso de Europa, esas mismas fuerzas son las que mantienen el océano en estado líquido bajo el hielo.

No obstante, los resultados muestran que la tensión generada por las mareas apenas alcanza alrededor del 3 % de la necesaria para reactivar fracturas en el fondo oceánico. Incluso suponiendo que la roca esté debilitada tras miles de millones de años de deformación, la energía disponible seguiría siendo entre diez y doce veces inferior a la requerida para un proceso tectónico sostenido.

Otros mecanismos que no alcanzan

El equipo también analizó otras posibles fuentes de deformación interna. Una de ellas es la convección en el manto, la capa situada entre el núcleo rocoso y el océano. En teoría, el movimiento lento de materiales calientes podría generar tensiones suficientes para fracturar la base del océano.

Sin embargo, incluso en los escenarios más optimistas, la fuerza resultante de esa convección sería cientos de veces demasiado débil. Otra posibilidad considerada fue la contracción del interior de Europa a medida que se enfría con el paso del tiempo. Para que este proceso generara fracturas, el núcleo rocoso tendría que reducir su tamaño en aproximadamente un kilómetro, una cifra considerada poco realista dadas las propiedades físicas del satélite.

En conjunto, estos cálculos apuntan a un fondo oceánico estable y rígido, sin la dinámica necesaria para mantener un intercambio continuo entre el agua del océano y las rocas profundas.

El problema del equilibrio químico

La falta de fracturas activas tiene implicaciones directas para la química del océano de Europa. Sin grietas profundas, el agua solo puede interactuar con las capas superiores del fondo rocoso, limitando las reacciones químicas a unos pocos cientos de metros. Con el tiempo, esa zona alcanza un equilibrio químico con el océano que la cubre.

Cuando se llega a ese punto, las reacciones dejan de liberar energía aprovechable. Para organismos que dependan de la química agua-roca, esto supone una pérdida progresiva de su fuente de “alimento” energético. A diferencia de la Tierra, donde la tectónica de placas renueva constantemente la corteza oceánica, Europa carecería de un mecanismo comparable para reactivar el sistema.

Este escenario no descarta por completo la vida, pero sí reduce las probabilidades de encontrar ecosistemas extensos y dinámicos similares a los que rodean las fuentes hidrotermales terrestres.

Energía alternativa en un mundo helado

A pesar del panorama poco alentador, el estudio no cierra la puerta a la habitabilidad de Europa. Los autores destacan que existen fuentes de energía independientes de la tectónica activa. Una de ellas es la radiolisis, un proceso en el que la radiación procedente del decaimiento de elementos radiactivos como el uranio, el torio o el potasio rompe las moléculas de agua y produce hidrógeno.

En la Tierra, este mecanismo sostiene comunidades microbianas en rocas muy antiguas, a varios kilómetros de profundidad, completamente aisladas de la superficie. Estos microorganismos utilizan el hidrógeno generado como fuente de energía, demostrando que la vida puede subsistir en entornos extremadamente limitados.

La gran incógnita es si este tipo de energía sería suficiente para mantener un ecosistema completo en Europa o solo pequeñas poblaciones microbianas dispersas. La eficiencia del proceso y la disponibilidad de elementos radiactivos en el interior del satélite siguen siendo cuestiones abiertas.

Implicaciones para la exploración espacial

El hallazgo llega en un momento clave para la exploración de Europa. La misión Europa Clipper de la NASA, lanzada en 2024 y con llegada prevista al sistema joviano en 2030, tiene como objetivo principal evaluar la habitabilidad de la luna. El orbitador realizará decenas de sobrevuelos cercanos, utilizando instrumentos capaces de medir el grosor del hielo, la composición química de la superficie y el flujo de calor interno.

Uno de los aspectos más esperados de la misión es la posible detección de géiseres o plumas de agua que emerjan a través de la corteza helada. Si existen, estas columnas podrían transportar material del océano al espacio, permitiendo analizar su composición sin necesidad de perforar el hielo.

Aunque Europa Clipper no está diseñada para estudiar directamente el fondo oceánico, sus mediciones ayudarán a refinar los modelos internos del satélite y a comprobar si las predicciones del nuevo estudio se ajustan a la realidad observada.

Un cambio de enfoque en la búsqueda de vida

La idea de un fondo oceánico inactivo obliga a replantear algunas estrategias de búsqueda de vida en Europa. En lugar de centrarse exclusivamente en analogías con las fuentes hidrotermales terrestres, los científicos podrían explorar otros escenarios, como microhábitats químicos sostenidos por radiación o procesos superficiales que introduzcan oxidantes en el océano.

Este cambio de perspectiva no resta importancia a Europa como objetivo científico, pero sí subraya la complejidad de evaluar la habitabilidad de mundos lejanos. La presencia de agua líquida, aunque fundamental, no garantiza por sí sola la existencia de vida.

A largo plazo, responder de forma definitiva a estas preguntas requerirá misiones aún más ambiciosas, capaces de penetrar la corteza helada y explorar directamente el océano oculto. Hasta entonces, estudios como este ayudan a afinar las expectativas y a comprender mejor los límites y posibilidades de uno de los mundos más intrigantes del sistema solar.

Webb Sees Jupiter-Size Exoplanet Being Roasted by Its Star

22 June 2026 at 16:05
An artist’s impression of the hot-Jupiter exoplanet HD 80606b. Image credit: NASA / ESA / CSA / Joseph Olmsted, STScI.

HD 80606b has one of the most extreme orbits of any known exoplanet and the NASA/ESA/CSA James Webb Space Telescope just caught it getting flash-fried as it whipped past its star.

The post Webb Sees Jupiter-Size Exoplanet Being Roasted by Its Star appeared first on Sci.News: Breaking Science News.

Earthlings on Europa? Provocative Study Explores ‘Reverse Panspermia’ Scenario Where Earth Life May Have Invaded an Alien Moon

21 June 2026 at 14:51

Astronomers have long wondered whether life on Earth might have had origins somewhere else in the cosmos. The idea that the key ingredients for life, or even simple organisms, might be carried through space by non-animate objects—a concept known as panspermia—has been proposed as one way such “seeding” of life on Earth might have occurred.

But what if it could also happen in reverse? In other words, what if life were one day found on an alien moon, which could later be traced back to Earth?

This is the very idea presented in a new study that explores the provocative idea that Jupiter’s frozen moon Europa may not only be hospitable, but that life from Earth could be thriving there.

In the new study, published in the International Journal of Astrobiology, astrophysicist Zaza Osmanov of the Free University of Tbilisi explored whether Earthly bacteria might have been able to escape our planet by traveling on microscopic dust particles, which, after escaping Earth’s gravity, could have drifted through space until they reached Europa.

There, a vast subsurface ocean is believed to exist beneath the moon’s icy crust, meaning that any simple organisms capable of escaping from Earth on tiny spacefaring rafts of dust might have found their way to a new home, and one that could support life.

Panspermia, but in Reverse

The long-debated idea of panspermia already presents the general idea for how this might work. However, Osmanov’s study investigates this idea in reverse order: not only might life on Earth have originated from elsewhere, but our planet could also hypothetically be the source of similar “seeding” events that might occur on alien worlds.

Based on mathematical models, Osmanov calculated how bacteria-rich dust grains could be launched into space, resulting from collisions with incoming dust in Earth’s upper atmosphere. Upon escaping the planet’s gravity, some of these bacteria might be able to sail along toward distant locales like Europa with the help of pressure generated by solar radiation—essentially the same concept as a solar light sail spacecraft, albeit much smaller.

With the help of solar radiation and occasional gravitational interactions, Osmanov theorizes that some particles might eventually be “steered” by such natural processes over time, eventually making their way to Jupiter.

Tiny Earthling Alien Invaders

Based on Osmanov’s estimates, there could potentially be as many as hundreds of millions of Earth-originating dust particles that might make their way to Europa every second. That’s a significant number, and although he estimates that the majority would be destroyed on impact, a small fraction could arrive at extremely shallow angles, which he believes may be able to survive landing on Europa’s surface.

However, even if a few bacterial invaders managed to survive, the next challenge they would face would be to reach the moon’s ocean that astronomers believe to be concealed beneath its icy exterior. Based on past studies, tidal forces generated by the massive host planet Jupiter offer a solution: such events are believed to likely cause fractures in Europa’s icy shell, which lead to the creation of entry points where surface materials might be capable of migrating downward.

Adding to this, Osmanov also points to instances where ice melting may also provide a means for the movement of material from the surface down into the moon’s hidden ocean. Over periods of thousands of years, some of these tiny bacterial invaders might make their way past the harsh surface environment and down into the moon’s far more hospitable subsurface ocean.

Osmanov estimates that there may be considerable numbers of Earth-derived particles that could reach Europa’s ocean over geological timescales. This could mean that terrestrial particles, Earthly microbes that have made the journey, may have had time to establish themselves as microbial colonists—if, of course, current presumptions about the moon’s conditions for supporting life are correct.

While the theory remains speculative, and Osmanov concedes that it cannot be tested directly at present, it suggests something fascinating: that the eventual discovery of life on an alien world could have ancestral links to our own planetary home.

Osmanov’s recent study, “Earth as a potential source of life for Europa’s subsurface ocean,” appeared in the journal International Journal of Astrobiology.

Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.

Radar Observations Reveal New Clues about Europa’s Hidden Interior

17 June 2026 at 19:57
This artist’s impression shows radar waves from NASA’s Goldstone Solar System Radar pinging Europa; the radar waves penetrate Europa’s icy surface before bouncing back to be collected by NSF’s Green Bank Telescope on Earth. Image credit: NSF / AUI / NSF’s NRAO / P.Vosteen.

Using NASA’s Goldstone Solar System Radar and NSF’s Green Bank Telescope, astronomers from the University of California, Los Angeles, confirmed that the icy surface of Jupiter’s moon Europa scatters radio energy in an unusually strong and complex way not seen on rocky worlds.

The post Radar Observations Reveal New Clues about Europa’s Hidden Interior appeared first on Sci.News: Breaking Science News.

Jupiter’s Atmosphere Holds Steady

13 March 2026 at 16:00

A close-up photograph of Jupiter. Dramatic cloud bands encircle the planet, and a large dark shadow of a nearby moon appears at left.

Jupiter’s upper atmosphere is hundreds of degrees hotter than it has any right to be, and for decades astronomers could only study it in brief, seemingly chaotic glimpses. New global maps built from years of observations have finally revealed the big picture — and it is surprisingly calm.

Order from Chaos

Although we’re well acquainted with Jupiter, having sent eight spacecraft on close passages and lived with it dominating the night sky for millennia, some of its simplest characteristics continue to puzzle us. For example, high above Jupiter’s cloud bands, temperatures exceed 800 K — far hotter than we’d expect given the meager sunlight that reaches that distance. Astronomers have long suspected that this excess is deposited by energy from the planet’s brilliant polar auroras, but previous observations provided only localized, sporadic snapshots that collectively painted a confusing picture of an ever-changing landscape.

A photograph of Jupiter seen in red/orange false color with a dark stripe down the middle.

Jupiter as seen by the slit camera on the Keck telescope during one of the team’s observations. The spectrograph slit is the dark vertical band stretching from the equator to the north pole, and the Great Red Spot appears in black at the lower right. [Adapted from Roberts et al. 2026]

To truly understand how Jupiter’s upper atmosphere got so hot and whether it was actually changing over time, astronomers needed to construct a global, comprehensive map — and then do so repeatedly over several years and look for any changes. A team led by Kate Roberts (Boston University) has now assembled just this sequence using the NIRSPEC instrument at the Keck Observatory. The researchers collected over 175,000 high-resolution infrared spectra across 14 nights from 2022 to 2025; they then processed the massive dataset to extract the emission from a charged form of hydrogen, H3+. This species is a standard natural thermometer that glows at infrared wavelengths, and by mapping the spectra to their corresponding specific locations on Jupiter, the team could construct the first true global maps of Jupiter’s upper atmospheric temperature, density, and radiance.

Consistency is Key

A look at how the maps evolved over time revealed striking order: the spatial patterns remained nearly constant, and the temperatures barely changed even over years. In general, the team noted that temperature decreases smoothly from the auroral regions near the poles (~1,150 K) to the equator (~750 K) at every longitude, and that although there is some night-to-night temperature variation, things stay remarkably steady over the years-long baseline.

A 2D heatmap with longitude on the bottom axis and latitude on the vertical axis. There is a general trend towards higher temperatures at higher latitudes.

A map of the average temperature of Jupiter’s upper atmosphere, as measured by the new Keck NIRSPEC data. Click to enlarge. [Adapted from Roberts et al. 2026]

What once “appeared stochastic,” the authors write, “exhibits predominantly spatial rather than temporal variability.” Earlier observations were simply sampling different longitudes at different times, mistaking geography for weather.

The conclusion that the upper atmosphere is complex but steady has implications beyond just Jupiter, as the team notes that JWST has already observed spatial patterns in the temperatures of the upper atmospheres of both Uranus and Neptune. As Roberts and colleagues note, “similar physical mechanisms could give rise to comparably stable structures” on those distant ice giants, meaning this analysis could ground our understanding of the upper atmospheres of giant worlds across the solar system.

Citation

“A Global View of Jupiter’s Upper Atmosphere Through H3+,” Kate Roberts et al 2026 ApJL 998 L13. doi:10.3847/2041-8213/ae3c9b

The post Jupiter’s Atmosphere Holds Steady appeared first on AAS Nova.

A Close Look at an Ancient Moon

5 September 2025 at 17:00

A photograph of a heavily cratered moon on a black background.

By piecing together observations from dozens of radio telescopes in Chile, planetary scientists recently completed the first-ever map of Callisto’s emission at millimeter wavelengths.

Old and Cold

In striking contrast to Io’s frenzied volcanism and Europa’s cracking ice shell, Jupiter’s moon Callisto is much quieter and colder than its Galilean siblings. Though a liquid water ocean hypothetically sloshes beneath its frigid surface, it’d be hard to infer that just by looking at the moon. Callisto’s terrain is ancient, static, and bears the scars of the millennia of exposure to space. There are no volcanoes, plate tectonics, or any other features to disturb what researchers call “evolved ruins” of the numerous craters. These have names like Valhalla, Asgard, and Lofn, since Callisto’s geologic features are named after settings and characters in Norse mythology to further reinforce their freezing existence.

This never-reset canvas makes Callisto an ideal laboratory for studying the long-term effects of asteroid impacts, dust accumulation from nearby natural satellites, and other processes that modify a planetary surface over time. One way to infer the composition and structure of the first few meters of material is to observe the way the temperature changes over the course of a day. For example, ice and rock respond differently to temperature changes; similarly, small-grains of either material warm up and cool down at different speeds than their larger-grain counterparts.

An image of a purple-orange blob against a black background.

The residuals from one of ALMA’s observations of Callisto. [Adapted from Camarca et al. 2025]

In theory, planetary scientists can measure the temperature of a moon by noting how bright each patch of its surface appears in millimeter-wavelength observations. However, this is easier said than done, as only a handful of telescopes are capable of seeing Callisto as anything more than a fuzzy blob at those wavelengths. Back in 2016–2017, planetary scientists used the Atacama Large Millimeter/submillimeter Array (ALMA), a radio interferometer in Chile, to attempt the challenging feat of making a map of Callisto’s surface.

Mapping from Afar

A team led by Maria Camarca, California Institute of Technology, just finished churning through all of the data and assembling their map of Callisto’s temperature residuals. Though the final spatial resolution was at best a few hundred kilometers, meaning a comparable map of Earth would blur all of New England together, this represents the most detailed thermal map of Callisto yet. The map was detailed enough to easily spot the largest craters, and several impact craters including Valhalla stood out as being 3–5K colder than all of the surrounding terrain. The team spotted another anomalously cold region that coincides with the location of maximum carbon dioxide gas density recently seen with JWST.

A multi-panel figure of a black and white surface beneath transparent red and blue blobs.

A map of Callisto’s thermal emission (red/blue) overlaid atop visible images of the surface collected by spacecraft. Click to enlarge. [Camarca et al. 2025]

The team also found that their data could not be explained by a simple model for Callisto’s surface that assumed one dominant material and structure. Instead, their images were better explained by more complex simulations that use two different thermal inertias. Though they are not sure yet why this may be, it is clear that Callisto, often overlooked compared to its flashier siblings, is a complex world worthy of further study. Luckily, the upcoming Jupiter Icy Moons Explorer mission and ALMA’s Wideband Sensitivity Upgrade will bring new knowledge of Callisto’s ancient surface.

Citation

“A Multifrequency Global View of Callisto’s Thermal Properties from ALMA,” Maria Camarca et al 2025 Planet. Sci. J. 6 183. doi:10.3847/PSJ/ade7ee

The post A Close Look at an Ancient Moon appeared first on AAS Nova.

If Jupiter Disappeared Would Earth Face More Asteroid Hits?

27 February 2026 at 13:56

Jupiter dominates the Solar System’s architecture. At about 318 times Earth’s mass and orbiting far beyond Mars, it acts as a gravitational gatekeeper, tugging on asteroids and comets that might otherwise stay put or never reach the inner planets. Remove Jupiter from the picture and Earth’s impact environment would change in complicated ways. It would […]

The post If Jupiter Disappeared Would Earth Face More Asteroid Hits? appeared first on Curiosmos.

❌