El baile de los planetas (II)
David Barrado y Navascués
Seguimos con la discusión sobre qué es y qué no es un planeta…
La reunión de la asamblea general de la Unión Astronómica Internacional continua en Praga. En los diferentes corrillos domina la conversación sobre la propuesta de definición del término «planeta«. Me comentan que el disgusto de un número significativo de astrónomos es grande, el desacuerdo es evidente. La política domina. El sector americano insiste en conservar el status para Plutón, y garantizarlo para 2003 UB(313), ambos descubiertos por americanos, de manera que el Sistema Solar contendría doce planetas en lugar de los nueve tradicionales (o los ocho si se eliminase a Plutón de la lista, opción que yo apoyo). El lobby funciona a diferentes niveles. Un ejemplo, artículo de Gibor Basri y Mike Brown (descubridor de 2003 UB) en astro-ph, el repositorio de artículos astronómicos, esta misma mañana.
Mientas tanto, una propuesta alternativa adquiere más y más fuerza. La votación será este mismo jueves.
Propuesta alternativa, que traduciré a lo largo de la mañana (cortesía de Javier Licandro):
New proposal for Resolution 5: Definition of a Planet
(1) A planet is a celestial body that (a) is by far the largest object in its local population [1], (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape [2], (c) does not produce energy by any nuclear fusion mechanism [3].
(2) According to point (1) the eight classical planets discovered before 1900, which move in nearly circular orbits close to the ecliptic plane are the only planets of our Solar System. All the other objects in orbit around the Sun are smaller than Mercury. We recognize that there are objects that fulfill the criteria (b) and (c) but not criterion (a). Those objects are defined as «dwarf» planets. Ceres as well as Pluto and several other large Trans-Neptunian objects belong to this category. In contrast to the planets, these objects typically have highly inclined orbits and/or large eccentricities.
(3) All the other natural objects orbiting the Sun that do not fulfill any of the previous criteria shall be referred to collectively as “Small Solar System Bodies”.[4]
PD: Traducción de la propuesta alternativa.
Un planeta es un objeto celeste que:
a) es el de mayor objeto de la población local,
b) contiene suficiente masa como para que su fuerza de gravedad sea dominante, de manera que se encuentre en equilibrio hidrostático,
c) no produce energía a partir de reacciones nucleares de fusión.
ENLACES:
Planetas: preguntas y respuestas de la IAU
Más en:
El baile de los planetas
El baile de los planetas (II)
El baile de los planetas (III)
¿Qué es un planeta?…
Now adding the homepage to my regular check rotation rather than waiting for individual links to find me, and a stop at blog44hits confirmed the rotation upgrade, the move from passive discovery to active checking is a vote of confidence in a sites ongoing quality and this site has earned that active engagement clearly.
Closed the tab with a small sense of finality rather than the usual rushed exit, and a stop at emmywrite produced the same considered closing, when reading ends with deliberate satisfaction rather than impatient skip you know the time was well spent and this site is producing those satisfying endings consistently across what I read.
Glad to find a site whose links lead somewhere worth going rather than back to itself for SEO juice, and a stop at austrasiaa kept that generous outbound feel, citing other peoples work with real respect rather than just for ranking signals is a sign of an honest operation worth supporting going forward.
Reading this on a long flight and finding it the best thing I read across hours of trying, and a stop at appgiant kept the streak going, when content beats long flight reading you know it has substance because flight reading is a hard test of a piece given the alternatives available everywhere.
Came away with a small but real shift in perspective on the topic, and a stop at oregoncityparks pushed that shift a bit further, the kind of subtle reframing that good writing does to a reader without making a big deal of it is something I always appreciate when it happens which is sadly not that often.
Found this through a friend who recommended it and now I see why, and a look at horizonhub only strengthened that recommendation in my own mind, word of mouth still works for content that actually delivers and this site is clearly earning recommendations the old fashioned way through quality rather than marketing.
Now feeling the rare pleasure of trusting a source completely on first encounter, and a look at acapparelstores extended that initial trust into something more durable, the calibration of trust to evidence is something I do informally and this site has earned high trust through the cumulative weight of multiple consistently good posts already.
Started imagining how I would explain the topic to someone else after reading, and a look at blog66glass gave me more material for that imagined explanation, content that improves my own ability to discuss a topic is content that has actually transferred knowledge rather than just decorating my screen for a few minutes.
Worth every minute of the time spent reading, and a stop at synoptica extends that value across more pages, in a media environment where most content is engineered to waste attention this site stands out by treating reader time as something valuable rather than something to be exploited and stretched as far as possible.